### Configure Gwyddion MinGW Cross-Compilation Setup Variables

Source: https://gwyddion.net/documentation/user-guide-en/installation-cross-mingw32

This code block shows an example of the `setup32` configuration file, which defines critical paths for the Gwyddion source code, MinGW installation, target installation directory, Win32 Python, and NSIS compiler. Users need to review and potentially adjust these variables, especially `source_dir`, before starting the cross-compilation process.

```Shell
source_dir=$HOME/Projects/Gwyddion/gwyddion-mingw
mingw_prefix=/usr/i686-pc-mingw32/sys-root/mingw
target_prefix=$HOME/opt/gwyddion-mingw32
python_dir=$HOME/.wine/drive_c/Python27
nsis_compiler=C:\\Program\\ Files\\ \(x86\\)\\NSIS\\makensis.exe
```

--------------------------------

### Install NSIS (Nullsoft Scriptable Install System) under Wine

Source: https://gwyddion.net/documentation/user-guide-en/installation-cross-mingw32

Install NSIS, a Windows program used for creating the Gwyddion installer, by running its setup executable through Wine. Version 3.06 or newer is recommended.

```Windows Command Prompt
wine nsis-3.06-setup.exe
```

--------------------------------

### Start Using a GwyResource

Source: https://gwyddion.net/documentation/head/libgwyddion/GwyResource

Initializes a GwyResource for proper use, creating auxiliary structures and performing necessary setup. This function acts as a constructor from a usage perspective and increments the GObject reference count. Resources should be released with `gwy_resource_release()` when no longer needed.

```C
void
gwy_resource_use (GwyResource *resource);
```

```APIDOC
gwy_resource_use:
  resource: A resource.
  Returns: void
```

--------------------------------

### Document API Introduction: gwy.ShapeFitPreset.setup

Source: https://gwyddion.net/documentation/head/pygwy/since-index

Documents the introduction of the `setup` method within the `gwy.ShapeFitPreset` class, introduced in version 2.47. This method is part of the Gwyddion library's API.

```APIDOC
gwy.ShapeFitPreset.setup
```

--------------------------------

### Get 3D Setup Object from Gwy3DView

Source: https://gwyddion.net/documentation/libgwydgets/Gwy3DView

Gets the 3D setup object of a 3D view. This is a convenience method that can be used instead of fetching the setup object from the data container.

```C
Gwy3DSetup *
gwy_3d_view_get_setup (Gwy3DView *gwy3dview);
```

```APIDOC
gwy_3d_view_get_setup(gwy3dview)
  Gets the 3D setup object of a 3D view.
  Parameters:
    gwy3dview: Gwy3DView * - A 3D data view widget.
  Returns:
    Gwy3DSetup * - The corresponding 3D setup.
```

--------------------------------

### gwy.gwy_app_setup_logging

Source: https://gwyddion.net/documentation/head/pygwy/since-index

Documents the introduction of the gwy.gwy_app_setup_logging function in version 2.45.

```APIDOC
gwy.gwy_app_setup_logging
```

--------------------------------

### Get Gwy3DView Setup Prefix

Source: https://gwyddion.net/documentation/head/libgwydgets/Gwy3DView

Retrieves the prefix identifying the 3D view setup within the container.

```C
const gchar *
gwy_3d_view_get_setup_prefix (Gwy3DView *gwy3dview);
```

```APIDOC
Parameters:
  gwy3dview: A 3D data view widget.
Returns:
  The setup key prefix.
```

--------------------------------

### Create new Gwy3DSetup instance

Source: https://gwyddion.net/documentation/head/libgwydgets/Gwy3DSetup

Documents the `gwy_3d_setup_new` function, which creates a new 3D view setup with default values. It returns a pointer to the newly created `Gwy3DSetup` object.

```APIDOC
Function: gwy_3d_setup_new
Signature: Gwy3DSetup * gwy_3d_setup_new (void)
Description: Creates a new 3D view setup with default values.
Returns: A newly created 3D view setup.
```

--------------------------------

### Introduce get Method in gwy.Surface

Source: https://gwyddion.net/documentation/head/pygwy/since-index

Documents the introduction of the `get` method within the `gwy.Surface` class, first available in Gwyddion version 2.45.

```APIDOC
gwy.Surface.get
```

--------------------------------

### Display GNU GPL Interactive Program Startup Notice

Source: https://gwyddion.net/documentation/user-guide-en/gpl

This example shows a short notice to be displayed by interactive programs upon startup, informing users about the program's free software status, lack of warranty, and where to find more details about the license terms.

```Text
      Gnomovision version 69, Copyright (C) year name of author Gnomovision
      comes with ABSOLUTELY NO WARRANTY; for details type "show w".
      This is free software, and you are welcome to redistribute it under
      certain conditions; type "show c" for details.
```

--------------------------------

### Get 3D View Setup Object (C)

Source: https://gwyddion.net/documentation/head/libgwydgets/Gwy3DView

Retrieves the 3D setup object associated with a 3D view. This function provides a convenient way to access the setup object without directly fetching it from the data container.

```C
Gwy3DSetup *
gwy_3d_view_get_setup (Gwy3DView *gwy3dview);
```

```APIDOC
gwy_3d_view_get_setup:
  description: Gets the 3D setup object of a 3D view. This is a convenience method that can be used instead of fetching the setup object from the data container.
  parameters:
    gwy3dview:
      type: Gwy3DView *
      description: A 3D data view widget.
  returns:
    type: Gwy3DSetup *
    description: The corresponding 3D setup.
```

--------------------------------

### Document gwy.gwy_volume_func_run API Introduction

Source: https://gwyddion.net/documentation/head/pygwy/since-index

Provides an introduction and version information for the `gwy.gwy_volume_func_run` API function, indicating its first appearance in the Gwyddion `gwy` module.

```APIDOC
gwy.gwy_volume_func_run (Introduced in version 2.32)
```

--------------------------------

### Document API Introduction: gwy.Spectra.__init__

Source: https://gwyddion.net/documentation/head/pygwy/since-index

Documents the introduction of the `__init__` method within the `gwy.Spectra` class, introduced in version 2.7. This method is part of the Gwyddion library's API.

```APIDOC
gwy.Spectra.__init__
```

--------------------------------

### Get Gwy3DView Setup Prefix

Source: https://gwyddion.net/documentation/libgwydgets/Gwy3DView

Retrieves the string prefix used to identify the 3D view's setup parameters within its container. This prefix helps organize and locate view-specific settings.

```C
const gchar *
gwy_3d_view_get_setup_prefix (Gwy3DView *gwy3dview);
```

```APIDOC
Function: gwy_3d_view_get_setup_prefix
Parameters:
  gwy3dview: A 3D data view widget.
Returns:
  The setup key prefix.
```

--------------------------------

### Document gwy.gwy_xyz_func_run API Introduction

Source: https://gwyddion.net/documentation/head/pygwy/since-index

Provides an introduction and version information for the `gwy.gwy_xyz_func_run` API function, indicating its first appearance in the Gwyddion `gwy` module.

```APIDOC
gwy.gwy_xyz_func_run (Introduced in version 2.45)
```

--------------------------------

### C Example: Deserializing an Object with gwy_serialize_unpack_object_struct

Source: https://gwyddion.net/documentation/libgwyddion/GwySerializable

Illustrates how to use 'gwy_serialize_unpack_object_struct' to deserialize a simple object with a single real number 'foo'. This example shows the setup of 'GwySerializeSpec' and the call to the deserialization function, omitting error checking for brevity.

```C
static GObject* my_object_deserialize(const guchar *buffer,
                                  gsize size,
                                  gsize *position) {
    double foo = 1.0;
    GwySerializeSpec spec[] = {
        { 'd', "foo", &foo, NULL, },
    };
    MyObject *my_object;

    gwy_serialize_unpack_object_struct(buffer, size, position,
                                       "MyObject",
                                       G_N_ELEMENTS(spec), spec);
    return my_object_new(foo);
}
```

--------------------------------

### Get Y-Offset of GwyLawn Origin

Source: https://gwyddion.net/documentation/head/libgwyprocess/GwyLawn

Retrieves the offset of the data lawn origin in the y direction. This value represents the starting point along the Y-axis.

```C
gdouble
gwy_lawn_get_yoffset (GwyLawn *lawn);
```

```APIDOC
Parameters:
  lawn (GwyLawn *): A data lawn.
Returns:
  gdouble: Offset value.
```

--------------------------------

### Document gwy.RGBA.__init__ API

Source: https://gwyddion.net/documentation/head/pygwy/since-index

Documents the introduction of the gwy.RGBA.__init__ API element within the gwy library.

```APIDOC
gwy.RGBA.__init__
```

--------------------------------

### Get Z-axis Offset of GwyBrick

Source: https://gwyddion.net/documentation/head/libgwyprocess/api-index-2-31

Retrieves the offset value for the Z-axis of the GwyBrick, typically representing the physical origin or starting point of the data along this dimension.

```APIDOC
gwy_brick_get_zoffset()
```

--------------------------------

### Gwy3DSetup API Reference

Source: https://gwyddion.net/documentation/libgwydgets/Gwy3DSetup

Comprehensive API documentation for the Gwy3DSetup object, detailing its structure, functions, properties, and inheritance within the Gwyddion library.

```APIDOC
Class: Gwy3DSetup
Description: Represents a basic 3D scene setup: viewpoint, projection, light, scale, etc.
Inherits: GObject
Implements: GwySerializable
Includes: #include <libgwydgets/gwydgets.h>

Functions:
  gwy_3d_setup_new():
    Signature: Gwy3DSetup * gwy_3d_setup_new (void);
    Description: Creates a new 3D view setup with default values.
    Returns: A newly created 3D view setup.

Properties:
  axes-visible:
    Type: gboolean
    Description: Whether axes are visible.
    Flags: Read / Write
    Default: TRUE
  fmscale-reserve-space:
    Type: gboolean
    Description: Whethere to reserve entire vertical stripe of the false colour scale.
    Flags: Read / Write
    Default: TRUE
    Since: 2.49
  fmscale-size:
    Type: double
    Description: Size of false colour scale relative to view height.
    Flags: Read / Write
    Allowed values: [0,1]
    Default: 1
    Since: 2.49
  fmscale-visible:
    Type: gboolean
    Description: Whether false color bar is visible.
    Flags: Read / Write
    Default: FALSE
  fmscale-y-align:
    Type: double
    Description: Vertical alignment of false colour scale.
    Flags: Read / Write
    Allowed values: [0,1]
    Default: 0.5
    Since: 2.49
  hide-masked:
    Type: gboolean
    Description: Hide masked vertices.
    Flags: Read / Write
    Default: FALSE
  labels-visible:
    Type: gboolean
    Description: Whether axis labels are visible if axes are visible.
    Flags: Read / Write
    Default: TRUE

Types and Values:
  struct Gwy3DSetup;
  struct Gwy3DSetupClass:
    Definition:
      GObjectClass parent_class;
      void (*reserved1)(void);
      void (*reserved2)(void);
```

--------------------------------

### Get Y-axis Offset of GwyBrick

Source: https://gwyddion.net/documentation/head/libgwyprocess/api-index-2-31

Retrieves the offset value for the Y-axis of the GwyBrick, typically representing the physical origin or starting point of the data along this dimension.

```APIDOC
gwy_brick_get_yoffset()
```

--------------------------------

### API Introduction: gwy.DataField.affine_prepare

Source: https://gwyddion.net/documentation/head/pygwy/since-index

Documents the introduction of the `gwy.DataField.affine_prepare` method in Gwyddion .NET API version 2.49.

```APIDOC
gwy.DataField.affine_prepare (Introduced in version 2.49)
```

--------------------------------

### API Introduction: gwy.Brick.__init__

Source: https://gwyddion.net/documentation/head/pygwy/since-index

An introduction or reference to the `gwy.Brick.__init__` method, first appearing in version 2.31.

```APIDOC
gwy.Brick.__init__
```

--------------------------------

### Get X-axis Offset of GwyBrick

Source: https://gwyddion.net/documentation/head/libgwyprocess/api-index-2-31

Retrieves the offset value for the X-axis of the GwyBrick, typically representing the physical origin or starting point of the data along this dimension.

```APIDOC
gwy_brick_get_xoffset()
```

--------------------------------

### gwy.DataLine.fft_window Method Introduction

Source: https://gwyddion.net/documentation/head/pygwy/since-index

Documents the introduction of the `fft_window` method within the `gwy.DataLine` class, indicating its availability from version 2.62.

```APIDOC
gwy.DataLine.fft_window()
  Introduced: 2.62
```

--------------------------------

### Get X-Offset of GwyLawn Origin

Source: https://gwyddion.net/documentation/head/libgwyprocess/GwyLawn

Retrieves the offset of the data lawn origin in the x direction. This value represents the starting point along the X-axis.

```C
gdouble
gwy_lawn_get_xoffset (GwyLawn *lawn);
```

```APIDOC
Parameters:
  lawn (GwyLawn *): A data lawn.
Returns:
  gdouble: Offset value.
```

--------------------------------

### Typical GwyNLFitPreset Usage Example

Source: https://gwyddion.net/documentation/head/libgwyddion/GwyNLFitPreset

This C code example illustrates the typical workflow for using GwyNLFitPreset to perform non-linear fitting. It demonstrates how to retrieve a specific preset (e.g., 'Gaussian'), allocate memory for parameters and errors, guess initial parameter values, execute the fitting process, and properly free allocated resources.

```C
GwyNLFitPreset *preset;
GwyNLFitter *fitter;
gdouble *params, *errors;

preset = gwy_inventory_get_item(gwy_nlfit_presets(), "Gaussian");
params = g_new(gdouble, gwy_nlfit_preset_get_nparams(preset));
errors = g_new(gdouble, gwy_nlfit_preset_get_nparams(preset));
/* Use a priori parameter value information, or: */
gwy_nlfit_preset_guess(preset, ndata, xdata, ydata, params, &ok);
fitter = gwy_nlfit_preset_fit(preset, NULL,
                              ndata, xdata, ydata, params,
                              params, errors, NULL);

/* Examine fitting status, parameters and errors... */

g_free(params);
g_free(errors);
gwy_math_nlfit_free(fitter);
```

--------------------------------

### Get Current Text Header Context Line Number (C)

Source: https://gwyddion.net/documentation/libgwyapp/libgwyapp-file-module-utils

Retrieves the current line number being processed within a GwyTextHeaderContext. Line numbers start from zero.

```C
guint
gwy_text_header_context_get_lineno (const GwyTextHeaderContext *context);
```

```APIDOC
gwy_text_header_context_get_lineno:
  Gets the current header line.
  Parameters:
    context: Header parsing context.
  Returns: The current line number, starting from zero.
  Since: 2.18
```

--------------------------------

### Get Y Offset for GwyDataField

Source: https://gwyddion.net/documentation/head/libgwyprocess/api-index-all

Retrieves the Y-axis offset of a GwyDataField. This function indicates the starting position of the data field along the vertical axis. It is part of the GwyDataField module.

```APIDOC
gwy_data_field_get_yoffset()
Type: function
Module: GwyDataField
```

--------------------------------

### Introduce gwy.gwy_app_data_browser_copy_xyz

Source: https://gwyddion.net/documentation/head/pygwy/since-index

Documents the introduction of the `gwy.gwy_app_data_browser_copy_xyz` function, indicating its availability from version 2.45 onwards.

```APIDOC
Function: gwy.gwy_app_data_browser_copy_xyz
Introduced in version: 2.45
```

--------------------------------

### API Introduction: gwy.AppDataId.verify_spectra

Source: https://gwyddion.net/documentation/head/pygwy/since-index

An introduction or reference to the `gwy.AppDataId.verify_spectra` method, first appearing in version 2.41.

```APIDOC
gwy.AppDataId.verify_spectra
```

--------------------------------

### Get Current Text Header Context Line Number

Source: https://gwyddion.net/documentation/head/libgwyapp/libgwyapp-file-module-utils

Retrieves the current line number being processed within a GwyTextHeaderContext. The line numbering starts from zero.

```C
guint
gwy_text_header_context_get_lineno (const GwyTextHeaderContext *context);
```

```APIDOC
gwy_text_header_context_get_lineno():
  Description: Gets the current header line.
  Parameters:
    context:
      type: const GwyTextHeaderContext *
      description: Header parsing context.
  Returns:
    type: guint
    description: The current line number, starting from zero.
  Since: 2.18
```

--------------------------------

### Get GwyTipModel Preset Group Name

Source: https://gwyddion.net/documentation/head/libgwyprocess/libgwyprocess-tip

Retrieves the group name to which a `GwyTipModelPreset` belongs, for example, 'analytical'. This helps categorize and organize different tip models.

```APIDOC
gwy_tip_model_get_preset_group_name:
  Signature: const gchar * gwy_tip_model_get_preset_group_name (const GwyTipModelPreset *preset)
  Parameters:
    preset: const GwyTipModelPreset * (Tip model preset)
  Returns: const gchar * (Preset group name)
```

--------------------------------

### Introduce gwy.gwy_app_data_browser_find_volume_by_title

Source: https://gwyddion.net/documentation/head/pygwy/since-index

Documents the introduction of the `gwy.gwy_app_data_browser_find_volume_by_title` function, indicating its availability from version 2.45 onwards.

```APIDOC
Function: gwy.gwy_app_data_browser_find_volume_by_title
Introduced in version: 2.45
```

--------------------------------

### Get X Offset for GwyDataField

Source: https://gwyddion.net/documentation/head/libgwyprocess/api-index-all

Retrieves the X-axis offset of a GwyDataField. This function indicates the starting position of the data field along the horizontal axis. It is part of the GwyDataField module.

```APIDOC
gwy_data_field_get_xoffset()
Type: function
Module: GwyDataField
```

--------------------------------

### Introduce gwy.gwy_app_current_tool

Source: https://gwyddion.net/documentation/head/pygwy/since-index

Documents the introduction of the `gwy.gwy_app_current_tool` function, indicating its availability from version 2.55 onwards.

```APIDOC
Function: gwy.gwy_app_current_tool
Introduced in version: 2.55
```

--------------------------------

### Get Value Format for Y-Coordinates (gwy.DataLine)

Source: https://gwyddion.net/documentation/head/pygwy/gwy.DataLine-class

This method finds a suitable value format for displaying the values (Y-coordinates) of a data line. It takes a style parameter to guide the formatting.

```APIDOC
gwy.DataLine.get_value_format_y(style)
```

--------------------------------

### Check Help System Availability (C API)

Source: https://gwyddion.net/documentation/head/libgwyapp/libgwyapp-help

Performs a weak check to determine if the help system is potentially available. It verifies the presence of a help backend, the user guide module map, and local user guide directory if applicable. A `TRUE` return does not guarantee full functionality, but `FALSE` indicates help will not work.

```C
gboolean
gwy_help_is_available (void);
```

```APIDOC
gwy_help_is_available:
  Parameters: None
  Returns: gboolean - TRUE if help seems available, FALSE if it is not.
  Since: 2.38
```

--------------------------------

### Get Y Offset of DataField Origin

Source: https://gwyddion.net/documentation/head/pygwy/gwy.DataField-class

Retrieves the Y offset of the data field's origin. This indicates the physical starting position along the Y-axis relative to a global coordinate system.

```APIDOC
gwy.DataField.get_yoffset()
```

--------------------------------

### Document gwy.SelectionGraphZoom.__init__ API

Source: https://gwyddion.net/documentation/head/pygwy/since-index

Documents the introduction of the gwy.SelectionGraphZoom.__init__ API element within the gwy library.

```APIDOC
gwy.SelectionGraphZoom.__init__
```

--------------------------------

### Introduce gwy.gwy_app_data_browser_copy_volume

Source: https://gwyddion.net/documentation/head/pygwy/since-index

Documents the introduction of the `gwy.gwy_app_data_browser_copy_volume` function, indicating its availability from version 2.32 onwards.

```APIDOC
Function: gwy.gwy_app_data_browser_copy_volume
Introduced in version: 2.32
```

--------------------------------

### Get Value Format for X-Coordinates (gwy.DataLine)

Source: https://gwyddion.net/documentation/head/pygwy/gwy.DataLine-class

This method finds a suitable value format for displaying the coordinates along the X-axis of a data line. It takes a style parameter to guide the formatting.

```APIDOC
gwy.DataLine.get_value_format_x(style)
```

--------------------------------

### Gwyddion Expression Language: Identifiers

Source: https://gwyddion.net/documentation/user-guide-en/expression-syntax

Examples of valid identifiers for functions, constants, and variables in the Gwyddion expression language. Identifiers start with a letter and can contain letters, numbers, or underscores.

```Gwyddion Expression Language
pow10
Pi
d2_2
```

--------------------------------

### Introduce gwy.gwy_app_data_browser_select_volume

Source: https://gwyddion.net/documentation/head/pygwy/since-index

Documents the introduction of the `gwy.gwy_app_data_browser_select_volume` function, indicating its availability from version 2.32 onwards.

```APIDOC
Function: gwy.gwy_app_data_browser_select_volume
Introduced in version: 2.32
```

--------------------------------

### Introduce gwy.gwy_app_data_browser_get

Source: https://gwyddion.net/documentation/head/pygwy/since-index

Documents the introduction of the `gwy.gwy_app_data_browser_get` function, indicating its availability from version 2.41 onwards.

```APIDOC
Function: gwy.gwy_app_data_browser_get
Introduced in version: 2.41
```

--------------------------------

### Get Number of Preset Graph Colors (C API)

Source: https://gwyddion.net/documentation/head/libgwydgets/libgwydgets-GwyGraphBasics

Returns the total number of distinct preset colors available through gwy_graph_get_preset_color(). This count indicates how many unique colors can be retrieved before they start repeating.

```APIDOC
gwy_graph_get_n_preset_colors(): guint
  Returns: The number of distinct colors.
```

--------------------------------

### Get GwyContainer Quark Keys with Prefix

Source: https://gwyddion.net/documentation/libgwyddion/GwyContainer

Retrieves quark keys from a GwyContainer that start with a given prefix. This function returns a newly allocated, zero-terminated array of GQuark keys. The number of keys can optionally be stored in `n`.

```C
GQuark *
gwy_container_keys_with_prefix (GwyContainer *container,
                                const gchar *prefix,
                                guint *n);
```

```APIDOC
Function: gwy_container_keys_with_prefix
Parameters:
  container: GwyContainer * - A container.
  prefix: const gchar * - A nul-terminated id prefix.
  n: guint * - Location to store the number of keys to. Can be NULL.
Returns:
  GQuark * - A newly allocated array with quark keys, in no particular order. The array is zero-terminated.
Since: 2.50
```

--------------------------------

### gwy.gwy_app_find_window_for_volume API Introduction

Source: https://gwyddion.net/documentation/head/pygwy/since-index

Documents the introduction of the 'gwy.gwy_app_find_window_for_volume' function in Gwyddion version 2.42.

```APIDOC
gwy.gwy_app_find_window_for_volume
  Introduced: 2.42
```

--------------------------------

### Get X Offset of DataField Origin

Source: https://gwyddion.net/documentation/head/pygwy/gwy.DataField-class

Retrieves the X offset of the data field's origin. This indicates the physical starting position along the X-axis relative to a global coordinate system.

```APIDOC
gwy.DataField.get_xoffset()
```

--------------------------------

### gwy.DataLine.check_compatibility_with_brick_z Method Introduction

Source: https://gwyddion.net/documentation/head/pygwy/since-index

Documents the introduction of the `check_compatibility_with_brick_z` method within the `gwy.DataLine` class, indicating its availability from version 2.51.

```APIDOC
gwy.DataLine.check_compatibility_with_brick_z()
  Introduced: 2.51
```

--------------------------------

### Build Gwyddion Windows Installer

Source: https://gwyddion.net/documentation/user-guide-en/installation-cross-mingw32

These commands execute the `cross-build-32` or `cross-build-64` scripts, which automate all steps necessary to cross-compile Gwyddion and create a Windows installer for the specified architecture. Upon successful completion, the executable installer will be located in the `$target_prefix` directory.

```Shell
./cross-build-32
```

```Shell
./cross-build-64
```

--------------------------------

### GwyContainer: Get Quark Keys with Prefix

Source: https://gwyddion.net/documentation/head/libgwyddion/GwyContainer

Retrieves quark keys from a GwyContainer that start with a specified prefix. Returns a newly allocated, zero-terminated array of GQuark keys. The number of keys can optionally be stored in `n`.

```C
GQuark *
gwy_container_keys_with_prefix (GwyContainer *container,
                                const gchar *prefix,
                                guint *n);
```

```APIDOC
Function: gwy_container_keys_with_prefix
Description: Gets quark keys of a container that start with given prefix.
Parameters:
  container: GwyContainer * - A container.
  prefix: const gchar * - A nul-terminated id prefix.
  n: guint * - Location to store the number of keys to. Can be NULL.
Returns:
  GQuark * - A newly allocated array with quark keys, in no particular order. The array is zero-terminated.
Since: 2.50
```

--------------------------------

### Document gwy.gwy_widget_sync_sensitivity API Introduction

Source: https://gwyddion.net/documentation/head/pygwy/since-index

Provides an introduction and version information for the `gwy.gwy_widget_sync_sensitivity` API function, indicating its first appearance in the Gwyddion `gwy` module.

```APIDOC
gwy.gwy_widget_sync_sensitivity (Introduced in version 2.8)
```

--------------------------------

### Introduce gwy.gwy_app_data_browser_get_gui_enabled

Source: https://gwyddion.net/documentation/head/pygwy/since-index

Documents the introduction of the `gwy.gwy_app_data_browser_get_gui_enabled` function, indicating its availability from version 2.21 onwards.

```APIDOC
Function: gwy.gwy_app_data_browser_get_gui_enabled
Introduced in version: 2.21
```

--------------------------------

### Get SI Unit Format with Significant Digits (gwy_si_unit_get_format_with_digits)

Source: https://gwyddion.net/documentation/libgwyddion/GwySIUnit

Determines an appropriate format for representing values with a specified number of significant digits. The resulting format guides how values should be printed, including magnitude, units, and decimal precision.

```C
GwySIValueFormat *
gwy_si_unit_get_format_with_digits (GwySIUnit *siunit,
                                    GwySIUnitFormatStyle style,
                                    gdouble maximum,
                                    gint sdigits,
                                    GwySIValueFormat *format);
```

```APIDOC
Parameters:
  siunit: An SI unit.
  style: Unit format style.
  maximum: The maximum value to be represented.
  sdigits: The number of significant digits the value should have.
  format: A value format to set-up, may be NULL, a new value format is allocated then.
Returns:
  The value format. If format was NULL, a newly allocated format is returned, otherwise (modified) format itself is returned.
```

--------------------------------

### Get Y offset of Gwyddion Lawn origin with Lawn.get_yoffset

Source: https://gwyddion.net/documentation/head/pygwy/gwy.Lawn-class

Retrieves the offset of the data lawn's origin in the y direction. This offset indicates the starting position of the data within a larger coordinate system.

```APIDOC
Lawn.get_yoffset()
  Description: Gets the offset of data lawn origin in y direction.
  Returns:
    float - Offset value.
  Since: 2.60
```

--------------------------------

### C Example: GwyDataView Setup for Data Previews

Source: https://gwyddion.net/documentation/head/libgwymodule/gwymodule-tutorial-process

This C code demonstrates how to initialize and configure a GwyDataView widget for displaying 2D data previews. It covers creating a GwyContainer, populating it with a data field, instantiating GwyDataView and GwyPixmapLayer, associating the layer with the data key '/0/data', and adjusting the zoom level for the preview. The example illustrates the use of raw data keys for container objects.

```C
GtkWidget *data_view;
GwyPixmapLayer *layer;
GwyContainer *mydata;
gdouble zoomval;

/* Create new container */
mydata = gwy_container_new();

/* Fill it with objects and auxiliary data, dfield and id were obtained
 * before. */
gwy_container_set_object_by_name(mydata, "/0/data", dfield);
gwy_app_sync_data_items(data, mydata, id, 0, FALSE,
                        GWY_DATA_ITEM_PALETTE,
                        GWY_DATA_ITEM_MASK_COLOR,
                        GWY_DATA_ITEM_RANGE,
                        0);

/* Create the data view and its layers */
data_view = gwy_data_view_new(mydata);
layer = gwy_layer_basic_new();
gwy_pixmap_layer_set_data_key(layer, "/0/data");
gwy_layer_basic_set_gradient_key(GWY_LAYER_BASIC(layer), "/0/base/palette");
gwy_data_view_set_base_layer(GWY_DATA_VIEW(data_view), layer);

/* Calculate preview size */
zoomval = PREVIEW_SIZE/(gdouble)MAX(gwy_data_field_get_xres(dfield),
                                    gwy_data_field_get_yres(dfield));
gwy_data_view_set_zoom(GWY_DATA_VIEW(data_view), zoomval);

/* Pack data_view somewhere... */
```

--------------------------------

### Quantitative MFM Data Processing Toolchain Example

Source: https://gwyddion.net/documentation/user-guide-en/mfm

This example provides a comprehensive, step-by-step guide for processing MFM data to obtain quantitative results using Gwyddion. It demonstrates the use of various Gwyddion modules, including force gradient recalculation, thresholding, stray field simulation, transfer function estimation, deconvolution, and arithmetic operations, applied to both calibration and test sample data.

```APIDOC
1. Convert calibration sample MFM phase data to MFM force gradient using
   [Recalculate to Force Gradient](mfm.html#mfm-data-conversion "Conversion to force gradient") with k 3.3 N/m and Q factor 226.
2. Add mask at 50% of the value using [thresholding](grain-analysis.html#grain-threshold "Thresholding").
3. Calculate the effective magnetic charge using
   [Perpendicular Media Stray field](mfm.html#mfm-field-simulation "Simulation of the stray field and MFM response") with
   130 nm film thickness, 500 kA/m magnetic charge, 12 pJ/m exchange constant,
   400 kJ/m³ uniaxial anisotropy, 0 deg cantilever angle and output Meff.
4. Calculate the TTF using [Transfer Function Guess](convolution-deconvolution.html#transfer-function-guess)
   with Wiener filter method, 65×65 TTF size and Welch window.
5. Convert MFM phase data of the test sample to MFM force gradient using [Recalculate to Force Gradient](mfm.html#mfm-data-conversion "Conversion to force gradient")
   with k 3.3 N/m and Q factor 226.
6. Scale the TTF to the pixel size of the test sample.
7. Use [Dimensions and Units](basic-operations.html#dimensions-and-units "Dimensions and Units") to match exactly the pixel size of the test sample measurements.
8. Deconvolve the cropped TTF from MFM force gradient on test sample using [Deconvolve](convolution-deconvolution.html#deconvolve "Image deconvolution"),
   using the maxium of L-curve curvature for obtaining best sigma.
9. Divide the resulting effective magnetic charge by 2 to get the stray field Hz
   using [Arithmetic](multidata.html#data-arithmetic "Arithmetic").
```

--------------------------------

### Introduce gwy.gwy_app_data_browser_select_brick

Source: https://gwyddion.net/documentation/head/pygwy/since-index

Documents the introduction of the `gwy.gwy_app_data_browser_select_brick` function, indicating its availability from version 2.61 onwards.

```APIDOC
Function: gwy.gwy_app_data_browser_select_brick
Introduced in version: 2.61
```

--------------------------------

### gwy_app_setup_logging

Source: https://gwyddion.net/documentation/libgwyapp/api-index-all

Sets up the application's logging system. This function is part of the logging module.

```APIDOC
gwy_app_setup_logging(): function in logging
```

--------------------------------

### Get GwyTipModel Preset by Name

Source: https://gwyddion.net/documentation/head/libgwyprocess/libgwyprocess-tip

Retrieves data associated with a specific tip model preset using its string name, for example, 'contact'. This provides a convenient way to access presets by their descriptive names.

```APIDOC
gwy_tip_model_get_preset_by_name:
  Signature: const GwyTipModelPreset * gwy_tip_model_get_preset_by_name (const gchar *name)
  Parameters:
    name: const gchar * (Name of tip, e.g., "contact")
  Returns: const GwyTipModelPreset * (Chosen preset data)
```

--------------------------------

### Get X offset of Gwyddion Lawn origin with Lawn.get_xoffset

Source: https://gwyddion.net/documentation/head/pygwy/gwy.Lawn-class

Retrieves the offset of the data lawn's origin in the x direction. This offset indicates the starting position of the data within a larger coordinate system.

```APIDOC
Lawn.get_xoffset()
  Description: Gets the offset of data lawn origin in x direction.
  Returns:
    float - Offset value.
  Since: 2.60
```

--------------------------------

### Check Help Availability (C API)

Source: https://gwyddion.net/documentation/libgwyapp/libgwyapp-help

Check whether help is available. This is a weak check that finds if we have any help-showing backend that might work at all, have the user guide module map, and if the user guide locations is a local directory it checks whether it exists. If it returns `TRUE` it does not guarantee help will work. If it returns `FALSE`, however, it means help will not work.

```C
gboolean
gwy_help_is_available (void);
```

```APIDOC
gwy_help_is_available:
  Parameters:
    - (void)
  Returns: gboolean - TRUE if help seems available, FALSE if it is not.
  Since: 2.38
```

--------------------------------

### gwy.DataLine.distribution Method Introduction

Source: https://gwyddion.net/documentation/head/pygwy/since-index

Documents the introduction of the `distribution` method within the `gwy.DataLine` class, indicating its availability from version 2.8.

```APIDOC
gwy.DataLine.distribution()
  Introduced: 2.8
```

--------------------------------

### Get Sum of Values in Data Line Part (C)

Source: https://gwyddion.net/documentation/libgwyprocess/libgwyprocess-linestats

This function computes the sum of all data points within a specified part of a GwyDataLine. It takes the data line, a starting index, and an ending index (exclusive) as input. It returns the calculated sum gdouble value.

```C
gdouble
gwy_data_line_part_get_sum (GwyDataLine *data_line,
                            gint from,
                            gint to);
```

```APIDOC
Function: gwy_data_line_part_get_sum
Description: Computes sum of all values in a part of a data line.
Parameters:
  data_line: A data line.
  from: Index the line part starts at.
  to: Index the line part ends at + 1.
Returns: Sum of all values within the interval.
```

--------------------------------

### Document API Introduction: gwy.Spectra.xytoi

Source: https://gwyddion.net/documentation/head/pygwy/since-index

Documents the introduction of the `xytoi` method within the `gwy.Spectra` class, introduced in version 2.7. This method is part of the Gwyddion library's API.

```APIDOC
gwy.Spectra.xytoi
```

--------------------------------

### Get Minimum Value of Data Line Part (C)

Source: https://gwyddion.net/documentation/libgwyprocess/libgwyprocess-linestats

This function finds the minimum value within a specified part of a GwyDataLine. It takes the data line, a starting index, and an ending index (exclusive) as input. It returns the minimum gdouble value found in the interval.

```C
gdouble
gwy_data_line_part_get_min (GwyDataLine *data_line,
                            gint from,
                            gint to);
```

```APIDOC
Function: gwy_data_line_part_get_min
Description: Finds the minimum value of a part of a data line.
Parameters:
  data_line: A data line.
  from: Index the line part starts at.
  to: Index the line part ends at + 1.
Returns: Minimum within given interval.
```

--------------------------------

### API Introduction: gwy.Brick.copy_zcalibration

Source: https://gwyddion.net/documentation/head/pygwy/since-index

An introduction or reference to the `gwy.Brick.copy_zcalibration` method, first appearing in version 2.52.

```APIDOC
gwy.Brick.copy_zcalibration
```

--------------------------------

### Get Maximum Value of Data Line Part (C)

Source: https://gwyddion.net/documentation/libgwyprocess/libgwyprocess-linestats

This function finds the maximum value within a specified part of a GwyDataLine. It takes the data line, a starting index, and an ending index (exclusive) as input. It returns the maximum gdouble value found in the interval.

```C
gdouble
gwy_data_line_part_get_max (GwyDataLine *data_line,
                            gint from,
                            gint to);
```

```APIDOC
Function: gwy_data_line_part_get_max
Description: Finds the maximum value of a part of a data line.
Parameters:
  data_line: A data line.
  from: Index the line part starts at.
  to: Index the line part ends at + 1.
Returns: Maximum within given interval.
```

--------------------------------

### Get Minimum Value of Data Line Part (Gwyddion C API)

Source: https://gwyddion.net/documentation/head/libgwyprocess/libgwyprocess-linestats

Finds the minimum value within a specified part of a GwyDataLine. This function takes the data line object, a starting index, and an ending index (exclusive) to define the segment of interest.

```APIDOC
gdouble gwy_data_line_part_get_min (GwyDataLine *data_line, gint from, gint to)
  Parameters:
    data_line (GwyDataLine*): A data line.
    from (gint): Index the line part starts at.
    to (gint): Index the line part ends at + 1.
  Returns: gdouble - Minimum within given interval.
```

--------------------------------

### gwy.DataLine.fft_raw Method Introduction

Source: https://gwyddion.net/documentation/head/pygwy/since-index

Documents the introduction of the `fft_raw` method within the `gwy.DataLine` class, indicating its availability from version 2.1.

```APIDOC
gwy.DataLine.fft_raw()
  Introduced: 2.1
```

--------------------------------

### GwyHelp Module API Reference

Source: https://gwyddion.net/documentation/head/libgwyapp/libgwyapp-help

API documentation for the GwyHelp module, detailing functions for integrating user guide access into Gwyddion dialogs and windows, along with related types.

```APIDOC
Module: help
Description: User guide access

Functions:
  void gwy_help_add_to_proc_dialog(GtkDialog *dialog, GwyHelpFlags flags)
    Description: Adds help to a data processing function dialog.
    Note: The help button will not be added if no help URI is found for the currently running function or help is not available.
    Parameters:
      dialog: Main dialog for a data processing function.
      flags: Flags allowing to modify the help setup.
    Since: 2.38

  void gwy_help_add_to_graph_dialog(GtkDialog *dialog, GwyHelpFlags flags)
    Description: Adds help to a graph function dialog.
    Note: The help button will not be added if no help URI is found for the currently running function or help is not available.
    Parameters:
      dialog: Main dialog for a graph function.
      flags: Flags allowing to modify the help setup.
    Since: 2.38

  void gwy_help_add_to_volume_dialog(GtkDialog *dialog, GwyHelpFlags flags)
    Description: Adds help to a volume data processing function dialog.
    Note: The help button will not be added if no help URI is found for the currently running function or help is not available.
    Parameters:
      dialog: Main dialog for a volume data processing function.
      flags: Flags allowing to modify the help setup.
    Since: 2.38

  void gwy_help_add_to_xyz_dialog(GtkDialog *dialog, GwyHelpFlags flags)
    Description: Adds help to a XYZ data processing function dialog.
    Note: The help button will not be added if no help URI is found for the currently running function or help is not available.
    Parameters:
      dialog: Main dialog for a XYZ data processing function.
      flags: Flags allowing to modify the help setup.
    Since: 2.45

  void gwy_help_add_to_cmap_dialog(GtkDialog *dialog, GwyHelpFlags flags)
    Description: Adds help to a curve map data processing function dialog.
    Note: The help button will not be added if no help URI is found for the currently running function or help is not available.
    Parameters:
      dialog: Main dialog for a curve map data processing function.
      flags: Flags allowing to modify the help setup.
    Since: 2.60

  void gwy_help_add_to_file_dialog()
  void gwy_help_add_to_tool_dialog()
  void gwy_help_add_to_window()
  void gwy_help_add_to_window_uri()
  void gwy_help_show()
  gboolean gwy_help_is_available()

Types and Values:
  enum GwyHelpFlags
```

--------------------------------

### Get Maximum Value of Data Line Part (Gwyddion C API)

Source: https://gwyddion.net/documentation/head/libgwyprocess/libgwyprocess-linestats

Finds the maximum value within a specified part of a GwyDataLine. This function takes the data line object, a starting index, and an ending index (exclusive) to define the segment of interest.

```APIDOC
gdouble gwy_data_line_part_get_max (GwyDataLine *data_line, gint from, gint to)
  Parameters:
    data_line (GwyDataLine*): A data line.
    from (gint): Index the line part starts at.
    to (gint): Index the line part ends at + 1.
  Returns: gdouble - Maximum within given interval.
```

--------------------------------

### Get Sum of Values in Data Line Part (Gwyddion C API)

Source: https://gwyddion.net/documentation/head/libgwyprocess/libgwyprocess-linestats

Computes the sum of all data points within a specified part of a GwyDataLine. This function takes the data line object, a starting index, and an ending index (exclusive) to define the segment of interest.

```APIDOC
gdouble gwy_data_line_part_get_sum (GwyDataLine *data_line, gint from, gint to)
  Parameters:
    data_line (GwyDataLine*): A data line.
    from (gint): Index the line part starts at.
    to (gint): Index the line part ends at + 1.
  Returns: gdouble - Sum of all values within the interval.
```

--------------------------------

### Introduce __init__ Constructor Method for gwy.Surface

Source: https://gwyddion.net/documentation/head/pygwy/since-index

Documents the introduction of the `__init__` constructor method within the `gwy.Surface` class, first available in Gwyddion version 2.45.

```APIDOC
gwy.Surface.__init__
```

--------------------------------

### Get Average Value of Data Line Part (C)

Source: https://gwyddion.net/documentation/libgwyprocess/libgwyprocess-linestats

This function computes the mean (average) value of all data points within a specified part of a GwyDataLine. It takes the data line, a starting index, and an ending index (exclusive) as input. It returns the calculated average gdouble value.

```C
gdouble
gwy_data_line_part_get_avg (GwyDataLine *data_line,
                            gint from,
                            gint to);
```

```APIDOC
Function: gwy_data_line_part_get_avg
Description: Computes mean value of all values in a part of a data line.
Parameters:
  data_line: A data line.
  from: Index the line part starts at.
  to: Index the line part ends at + 1.
Returns: Average value within given interval.
```

--------------------------------

### Document gwy.gwy_volume_func_get_menu_path API Introduction

Source: https://gwyddion.net/documentation/head/pygwy/since-index

Provides an introduction and version information for the `gwy.gwy_volume_func_get_menu_path` API function, indicating its first appearance in the Gwyddion `gwy` module.

```APIDOC
gwy.gwy_volume_func_get_menu_path (Introduced in version 2.32)
```

--------------------------------

### Run Gwyddion from Fink Installation

Source: https://gwyddion.net/documentation/user-guide-en/installation-osx

Executes the Gwyddion application installed via Fink by specifying its typical installation path. This command is used to launch Gwyddion after it has been installed through Fink.

```Shell
/usr/local/bin/gwyddion
```

--------------------------------

### Introduce gwy.gwy_app_data_browser_select_lawn

Source: https://gwyddion.net/documentation/head/pygwy/since-index

Documents the introduction of the `gwy.gwy_app_data_browser_select_lawn` function, indicating its availability from version 2.61 onwards.

```APIDOC
Function: gwy.gwy_app_data_browser_select_lawn
Introduced in version: 2.61
```

--------------------------------

### API Introduction: gwy.AppDataId.verify_xyz

Source: https://gwyddion.net/documentation/head/pygwy/since-index

An introduction or reference to the `gwy.AppDataId.verify_xyz` method, first appearing in version 2.46.

```APIDOC
gwy.AppDataId.verify_xyz
```

--------------------------------

### Add Help to Window (C API)

Source: https://gwyddion.net/documentation/libgwyapp/libgwyapp-help

Adds help to a window pointing to the user guide. If the window is a GtkDialog a help button will be added by default (this can be modified with `flags`). Normal windows do not get help buttons. No help may be added if help is not available. This is a relatively low-level function and should not be necessary in modules. An exception may be modules with multiple user interfaces described in different parts of the guide – but this should be rare. It is a suitable functions for adding help to base application windows, such as channel or volume windows.

```C
void
gwy_help_add_to_window (GtkWindow *window,
                        const gchar *filename,
                        const gchar *fragment,
                        GwyHelpFlags flags);
```

```APIDOC
gwy_help_add_to_window:
  Parameters:
    - window: A window.
    - filename: Base file name in the user guide without any path or extensions, for instance "statistical-analysis".
    - fragment: Fragment identifier (without "#"), or possibly NULL.
    - flags: Flags allowing to modify the help setup.
  Returns: void
  Since: 2.38
```

--------------------------------

### Get GwyContainer String Keys with Prefix by Name

Source: https://gwyddion.net/documentation/libgwyddion/GwyContainer

Retrieves string keys from a GwyContainer that start with a given prefix. This function returns a newly allocated, NULL-terminated array of `const gchar **` string keys. The number of keys can optionally be stored in `n`. The strings are owned by GLib and must not be freed.

```C
const gchar **
gwy_container_keys_with_prefix_by_name
                               (GwyContainer *container,
                                const gchar *prefix,
                                guint *n);
```

```APIDOC
Function: gwy_container_keys_with_prefix_by_name
Parameters:
  container: GwyContainer * - A container.
  prefix: const gchar * - A nul-terminated id prefix.
  n: guint * - Location to store the number of keys to. Can be NULL.
Returns:
  const gchar ** - A newly allocated array with string keys, in no particular order. Unlike the array the strings are owned by GLib and must not be freed. The array is NULL-terminated.
Since: 2.50
```

--------------------------------

### Introduce gwy.gwy_app_channel_log_add_proc

Source: https://gwyddion.net/documentation/head/pygwy/since-index

Documents the introduction of the `gwy.gwy_app_channel_log_add_proc` function, indicating its availability from version 2.38 onwards.

```APIDOC
Function: gwy.gwy_app_channel_log_add_proc
Introduced in version: 2.38
```

--------------------------------

### Document gwy.gwy_volume_func_get_tooltip API Introduction

Source: https://gwyddion.net/documentation/head/pygwy/since-index

Provides an introduction and version information for the `gwy.gwy_volume_func_get_tooltip` API function, indicating its first appearance in the Gwyddion `gwy` module.

```APIDOC
gwy.gwy_volume_func_get_tooltip (Introduced in version 2.32)
```

--------------------------------

### Get Average Value of Data Line Part (Gwyddion C API)

Source: https://gwyddion.net/documentation/head/libgwyprocess/libgwyprocess-linestats

Computes the mean (average) value of all data points within a specified part of a GwyDataLine. This function takes the data line object, a starting index, and an ending index (exclusive) to define the segment of interest.

```APIDOC
gdouble gwy_data_line_part_get_avg (GwyDataLine *data_line, gint from, gint to)
  Parameters:
    data_line (GwyDataLine*): A data line.
    from (gint): Index the line part starts at.
    to (gint): Index the line part ends at + 1.
  Returns: gdouble - Average value within given interval.
```

--------------------------------

### Get Log-Scale Suitable Ranges for GwyGraphCurveModel (C)

Source: https://gwyddion.net/documentation/libgwydgets/GwyGraphCurveModel

Retrieves the minimum and maximum displayable values for X and Y axes of a GwyGraphCurveModel, considering logarithmic scaling. It returns FALSE if no displayable data points exist under the specified log-scale setup, otherwise TRUE. The function's return values are cached for performance.

```C
gboolean
gwy_graph_curve_model_get_ranges (GwyGraphCurveModel *gcmodel,
                                  gboolean x_logscale,
                                  gboolean y_logscale,
                                  gdouble *x_min,
                                  gdouble *x_max,
                                  gdouble *y_min,
                                  gdouble *y_max);
```

--------------------------------

### Document API Introduction: gwy.Spectra.new_alike

Source: https://gwyddion.net/documentation/head/pygwy/since-index

Documents the introduction of the `new_alike` method within the `gwy.Spectra` class, introduced in version 2.7. This method is part of the Gwyddion library's API.

```APIDOC
gwy.Spectra.new_alike
```

--------------------------------

### GwyContainer: Get String Keys with Prefix by Name

Source: https://gwyddion.net/documentation/head/libgwyddion/GwyContainer

Retrieves string keys from a GwyContainer that start with a specified prefix. Returns a newly allocated, `NULL`-terminated array of `const gchar **` string keys. The number of keys can optionally be stored in `n`. The strings themselves are owned by GLib and must not be freed.

```C
const gchar **
gwy_container_keys_with_prefix_by_name
                               (GwyContainer *container,
                                const gchar *prefix,
                                guint *n);
```

```APIDOC
Function: gwy_container_keys_with_prefix_by_name
Description: Gets string keys of a container that start with given prefix.
Parameters:
  container: GwyContainer * - A container.
  prefix: const gchar * - A nul-terminated id prefix.
  n: guint * - Location to store the number of keys to. Can be NULL.
Returns:
  const gchar ** - A newly allocated array with string keys, in no particular order. Unlike the array the strings are owned by GLib and must not be freed. The array is NULL-terminated.
Since: 2.50
```

--------------------------------

### Introduce gwy.gwy_app_data_browser_select_spectra

Source: https://gwyddion.net/documentation/head/pygwy/since-index

Documents the introduction of the `gwy.gwy_app_data_browser_select_spectra` function, indicating its availability from version 2.7 onwards.

```APIDOC
Function: gwy.gwy_app_data_browser_select_spectra
Introduced in version: 2.7
```

--------------------------------

### gwy.gwy_app_wait_cursor_start

Source: https://gwyddion.net/documentation/head/pygwy/since-index

Documents the introduction of the gwy.gwy_app_wait_cursor_start function in version 2.3.

```APIDOC
gwy.gwy_app_wait_cursor_start
```