gwy_data_field_invalidate ()

void
gwy_data_field_invalidate (GwyDataField *data_field);

Invalidates cached data field stats.

User code should rarely need this macro, as all GwyDataField methods do proper invalidation when they change data, as well as gwy_data_field_get_data() does.

However, if you get raw data with gwy_data_field_get_data() and then mix direct changes to it with calls to methods like gwy_data_field_get_max(), you may need to explicitely invalidate cached values to let gwy_data_field_get_max() know it has to recompute the maximum.

gwy_data_field_duplicate()

#define             gwy_data_field_duplicate(data_field)

Convenience macro doing gwy_serializable_duplicate() with all the necessary typecasting.

Use gwy_data_field_new_alike() if you don't want to copy data, only resolutions and units.

gwy_data_field_assign()

#define             gwy_data_field_assign(dest, source)

Convenience macro making one data field identical to another.

This is just a gwy_serializable_clone() wrapper with all the necessary typecasting.

Since: 2.52

gwy_data_field_new ()

GwyDataField *
gwy_data_field_new (gint xres,
                    gint yres,
                    gdouble xreal,
                    gdouble yreal,
                    gboolean nullme);

Creates a new data field.

gwy_data_field_new_alike ()

GwyDataField *
gwy_data_field_new_alike (GwyDataField *model,
                          gboolean nullme);

Creates a new data field similar to an existing one.

Use gwy_data_field_duplicate() if you want to copy a data field including data.

gwy_data_field_data_changed ()

void
gwy_data_field_data_changed (GwyDataField *data_field);

Emits signal "data-changed" on a data field.

gwy_data_field_new_resampled ()

GwyDataField *
gwy_data_field_new_resampled (GwyDataField *data_field,
                              gint xres,
                              gint yres,
                              GwyInterpolationType interpolation);

Creates a new data field by resampling an existing one.

This method is equivalent to gwy_data_field_duplicate() followed by gwy_data_field_resample(), but it is more efficient.

gwy_data_field_resample ()

void
gwy_data_field_resample (GwyDataField *data_field,
                         gint xres,
                         gint yres,
                         GwyInterpolationType interpolation);

Resamples a data field using given interpolation method

This method may invalidate raw data buffer returned by gwy_data_field_get_data().

gwy_data_field_bin ()

void
gwy_data_field_bin (GwyDataField *data_field,
                    GwyDataField *target,
                    gint binw,
                    gint binh,
                    gint xoff,
                    gint yoff,
                    gint trimlowest,
                    gint trimhighest);

Bins a data field into another data field.

See gwy_data_field_new_binned() for a detailed description.

Since: 2.55

gwy_data_field_new_binned ()

GwyDataField *
gwy_data_field_new_binned (GwyDataField *data_field,
                           gint binw,
                           gint binh,
                           gint xoff,
                           gint yoff,
                           gint trimlowest,
                           gint trimhighest);

Creates a new data field by binning an existing one.

The data field is divided into rectangles of dimensions binw ×binh , offset by (xoff , yoff ). The values in each complete rectangle are averaged and the average becomes the pixel value in the newly created, smaller data field.

Note that the result is the average – not sum – of the individual values. Multiply the returned data field with binw ×binh if you want sum.

By giving non-zero trimlowest and trimhighest you can change the plain average to a trimmed one (even turning it to median in the extreme case). It must always hold that trimlowest + trimhighest is smaller than binw ×binh .

Since: 2.50

gwy_data_field_resize ()

void
gwy_data_field_resize (GwyDataField *data_field,
                       gint ulcol,
                       gint ulrow,
                       gint brcol,
                       gint brrow);

Resizes (crops) a data field.

Crops a data field to a rectangle between upper-left and bottom-right points, recomputing real size.

This method may invalidate raw data buffer returned by gwy_data_field_get_data().

gwy_data_field_area_extract ()

GwyDataField *
gwy_data_field_area_extract (GwyDataField *data_field,
                             gint col,
                             gint row,
                             gint width,
                             gint height);

Extracts a rectangular part of a data field to a new data field.

gwy_data_field_copy ()

void
gwy_data_field_copy (GwyDataField *src,
                     GwyDataField *dest,
                     gboolean nondata_too);

Copies the contents of an already allocated data field to a data field of the same size.

gwy_data_field_area_copy ()

void
gwy_data_field_area_copy (GwyDataField *src,
                          GwyDataField *dest,
                          gint col,
                          gint row,
                          gint width,
                          gint height,
                          gint destcol,
                          gint destrow);

Copies a rectangular area from one data field to another.

The area starts at (col , row ) in src and its dimension is width *height . It is copied to dest starting from (destcol , destrow ).

The source area has to be completely contained in src . No assumptions are made about destination position, however, parts of the source area sticking out the destination data field dest are cut off.

If src is equal to dest , the areas may not overlap.

gwy_data_field_get_data ()

gdouble *
gwy_data_field_get_data (GwyDataField *data_field);

Gets the raw data buffer of a data field.

The returned buffer is not guaranteed to be valid through whole data field life time. Some function may change it, most notably gwy_data_field_resize() and gwy_data_field_resample().

This function invalidates any cached information, use gwy_data_field_get_data_const() if you are not going to change the data.

See gwy_data_field_invalidate() for some discussion.

gwy_data_field_get_data_const ()

const gdouble *
gwy_data_field_get_data_const (GwyDataField *data_field);

Gets the raw data buffer of a data field, read-only.

The returned buffer is not guaranteed to be valid through whole data field life time. Some function may change it, most notably gwy_data_field_resize() and gwy_data_field_resample().

Use gwy_data_field_get_data() if you want to change the data.

See gwy_data_field_invalidate() for some discussion.

gwy_data_field_get_xres ()

gint
gwy_data_field_get_xres (GwyDataField *data_field);

Gets X resolution (number of columns) of a data field.

gwy_data_field_get_yres ()

gint
gwy_data_field_get_yres (GwyDataField *data_field);

Gets Y resolution (number of rows) of the field.

gwy_data_field_get_xreal ()

gdouble
gwy_data_field_get_xreal (GwyDataField *data_field);

Gets the X real (physical) size of a data field.

gwy_data_field_get_yreal ()

gdouble
gwy_data_field_get_yreal (GwyDataField *data_field);

Gets the Y real (physical) size of a data field.

gwy_data_field_set_xreal ()

void
gwy_data_field_set_xreal (GwyDataField *data_field,
                          gdouble xreal);

Sets X real (physical) size value of a data field.

gwy_data_field_set_yreal ()

void
gwy_data_field_set_yreal (GwyDataField *data_field,
                          gdouble yreal);

Sets Y real (physical) size value of a data field.

gwy_data_field_get_dx ()

gdouble
gwy_data_field_get_dx (GwyDataField *data_field);

Gets the horizontal pixel size of a data field in real units.

The result is the same as gwy_data_field_get_xreal(data_field)/gwy_data_field_get_xres(data_field).

Since: 2.52

gwy_data_field_get_dy ()

gdouble
gwy_data_field_get_dy (GwyDataField *data_field);

Gets the vertical pixel size of a data field in real units.

The result is the same as gwy_data_field_get_yreal(data_field)/gwy_data_field_get_yres(data_field).

Since: 2.52

gwy_data_field_get_xoffset ()

gdouble
gwy_data_field_get_xoffset (GwyDataField *data_field);

Gets the X offset of data field origin.

gwy_data_field_get_yoffset ()

gdouble
gwy_data_field_get_yoffset (GwyDataField *data_field);

Gets the Y offset of data field origin.

gwy_data_field_set_xoffset ()

void
gwy_data_field_set_xoffset (GwyDataField *data_field,
                            gdouble xoff);

Sets the X offset of a data field origin.

Note offsets don't affect any calculation, nor functions like gwy_data_field_rtoj().

gwy_data_field_set_yoffset ()

void
gwy_data_field_set_yoffset (GwyDataField *data_field,
                            gdouble yoff);

Sets the Y offset of a data field origin.

Note offsets don't affect any calculation, nor functions like gwy_data_field_rtoi().

gwy_data_field_get_si_unit_xy ()

GwySIUnit *
gwy_data_field_get_si_unit_xy (GwyDataField *data_field);

Returns lateral SI unit of a data field.

gwy_data_field_get_si_unit_z ()

GwySIUnit *
gwy_data_field_get_si_unit_z (GwyDataField *data_field);

Returns value SI unit of a data field.

gwy_data_field_set_si_unit_xy ()

void
gwy_data_field_set_si_unit_xy (GwyDataField *data_field,
                               GwySIUnit *si_unit);

Sets the SI unit corresponding to the lateral (XY) dimensions of a data field.

It does not assume a reference on si_unit , instead it adds its own reference.

gwy_data_field_set_si_unit_z ()

void
gwy_data_field_set_si_unit_z (GwyDataField *data_field,
                              GwySIUnit *si_unit);

Sets the SI unit corresponding to the "height" (Z) dimension of a data field.

It does not assume a reference on si_unit , instead it adds its own reference.

gwy_data_field_get_value_format_xy ()

GwySIValueFormat *
gwy_data_field_get_value_format_xy (GwyDataField *data_field,
                                    GwySIUnitFormatStyle style,
                                    GwySIValueFormat *format);

Finds value format good for displaying coordinates of a data field.

gwy_data_field_get_value_format_z ()

GwySIValueFormat *
gwy_data_field_get_value_format_z (GwyDataField *data_field,
                                   GwySIUnitFormatStyle style,
                                   GwySIValueFormat *format);

Finds value format good for displaying values of a data field.

gwy_data_field_copy_units ()

void
gwy_data_field_copy_units (GwyDataField *data_field,
                           GwyDataField *target);

Sets lateral and value units of a data field to match another data field.

Since: 2.49

gwy_data_field_copy_units_to_data_line ()

void
gwy_data_field_copy_units_to_data_line
                               (GwyDataField *data_field,
                                GwyDataLine *data_line);

Sets lateral and value units of a data line to match a data field.

gwy_data_line_copy_units_to_data_field ()

void
gwy_data_line_copy_units_to_data_field
                               (GwyDataLine *data_line,
                                GwyDataField *data_field);

Sets lateral and value units of a data field to match a data line.

gwy_data_field_itor ()

gdouble
gwy_data_field_itor (GwyDataField *data_field,
                     gdouble row);

Transforms vertical pixel coordinate to real (physical) Y coordinate.

That is it maps range [0..y-resolution] to range [0..real-y-size]. It is not suitable for conversion of matrix indices to physical coordinates, you have to use gwy_data_field_itor(data_field , row + 0.5) for that.

gwy_data_field_jtor ()

gdouble
gwy_data_field_jtor (GwyDataField *data_field,
                     gdouble col);

Transforms horizontal pixel coordinate to real (physical) X coordinate.

That is it maps range [0..x-resolution] to range [0..real-x-size]. It is not suitable for conversion of matrix indices to physical coordinates, you have to use gwy_data_field_jtor(data_field , col + 0.5) for that.

gwy_data_field_rtoi ()

gdouble
gwy_data_field_rtoi (GwyDataField *data_field,
                     gdouble realy);

Transforms real (physical) Y coordinate to row.

That is it maps range [0..real-y-size] to range [0..y-resolution].

gwy_data_field_rtoj ()

gdouble
gwy_data_field_rtoj (GwyDataField *data_field,
                     gdouble realx);

Transforms real (physical) X coordinate to column.

That is it maps range [0..real-x-size] to range [0..x-resolution].

gwy_data_field_get_val ()

gdouble
gwy_data_field_get_val (GwyDataField *data_field,
                        gint col,
                        gint row);

Gets value at given position in a data field.

Do not access data with this function inside inner loops, it's slow. Get the raw data buffer with gwy_data_field_get_data_const() and access it directly instead.

gwy_data_field_set_val ()

void
gwy_data_field_set_val (GwyDataField *data_field,
                        gint col,
                        gint row,
                        gdouble value);

Sets value at given position in a data field.

Do not set data with this function inside inner loops, it's slow. Get the raw data buffer with gwy_data_field_get_data() and write to it directly instead.

gwy_data_field_get_dval ()

gdouble
gwy_data_field_get_dval (GwyDataField *data_field,
                         gdouble x,
                         gdouble y,
                         GwyInterpolationType interpolation);

Gets interpolated value at arbitrary data field point indexed by pixel coordinates.

Note pixel values are centered in pixels, so to get the same value as gwy_data_field_get_val(data_field , j , i ) returns, it's necessary to add 0.5: gwy_data_field_get_dval(data_field , j +0.5, i +0.5, interpolation ).

See also gwy_data_field_get_dval_real() that does the same, but takes real coordinates.

gwy_data_field_get_dval_real ()

gdouble
gwy_data_field_get_dval_real (GwyDataField *data_field,
                              gdouble x,
                              gdouble y,
                              GwyInterpolationType interpolation);

Gets interpolated value at arbitrary data field point indexed by real coordinates.

See also gwy_data_field_get_dval() that does the same, but takes pixel coordinates.

gwy_data_field_rotate ()

void
gwy_data_field_rotate (GwyDataField *data_field,
                       gdouble angle,
                       GwyInterpolationType interpolation);

Rotates a data field by a given angle.

This function is mostly obsolete. See gwy_data_field_new_rotated() and gwy_data_field_new_rotated_90().

Values that get outside of data field by the rotation are lost. Undefined values from outside of data field that get inside are set to data field minimum value.

The rotation is performed in pixel space, i.e. it can be in fact a more general affine transform in the real coordinates when pixels are not square.

gwy_data_field_new_rotated ()

GwyDataField *
gwy_data_field_new_rotated (GwyDataField *dfield,
                            GwyDataField *exterior_mask,
                            gdouble angle,
                            GwyInterpolationType interp,
                            GwyRotateResizeType resize);

Creates a new data field by rotating a data field by an atribtrary angle.

The returned data field can have pixel corresponding to exterior in dfield (unless resize is GWY_ROTATE_RESIZE_CUT). They are filled with a neutral value; pass exterior_mask and replace them as you wish if you need more control.

The rotation is performed in real space, i.e. it is a more general affine transform in the pixel space for data field with non-square pixels. See gwy_data_field_rotate() which rotates in the pixel space.

The returned data field has always square pixels. If you want to rotate by a multiple of G_PI/2 while preserving non-square pixels, you must use explicitly a function such as gwy_data_field_new_rotated_90().

Since: 2.46

gwy_data_field_new_rotated_90 ()

GwyDataField *
gwy_data_field_new_rotated_90 (GwyDataField *data_field,
                               gboolean clockwise);

Creates a new data field by rotating a data field by 90 degrees.

Since: 2.46

gwy_data_field_invert ()

void
gwy_data_field_invert (GwyDataField *data_field,
                       gboolean yflipped,
                       gboolean xflipped,
                       gboolean zflipped);

Reflects and/or inverts a data field.

In the case of value (Z) reflection, it's inverted about the mean value.

Note the unusual axis argument order, with Y and X swapped. It is because historically the arguments were called X and Y, but had a somewhat idiosyncratic interpretation, doing the opposite of one might expect intuitively.

gwy_data_field_flip_xy ()

void
gwy_data_field_flip_xy (GwyDataField *src,
                        GwyDataField *dest,
                        gboolean minor);

Copies data from one data field to another with transposition.

The destination data field is resized as necessary, its real dimensions set to transposed src dimensions and its offsets are reset. Units are not updated.

Since: 2.49

gwy_data_field_area_flip_xy ()

void
gwy_data_field_area_flip_xy (GwyDataField *src,
                             gint col,
                             gint row,
                             gint width,
                             gint height,
                             GwyDataField *dest,
                             gboolean minor);

Copies data from a rectangular part of one data field to another with transposition.

The destination data field is resized as necessary, its real dimensions set to transposed src area dimensions and its offsets are reset. Units are not updated.

Since: 2.49

gwy_data_field_fill ()

void
gwy_data_field_fill (GwyDataField *data_field,
                     gdouble value);

Fills a data field with given value.

gwy_data_field_clear ()

void
gwy_data_field_clear (GwyDataField *data_field);

Fills a data field with zeroes.

gwy_data_field_multiply ()

void
gwy_data_field_multiply (GwyDataField *data_field,
                         gdouble value);

Multiplies all values in a data field by given value.

gwy_data_field_add ()

void
gwy_data_field_add (GwyDataField *data_field,
                    gdouble value);

Adds given value to all values in a data field.

gwy_data_field_abs ()

void
gwy_data_field_abs (GwyDataField *data_field);

Takes absolute value of all values in a data field.

Since: 2.52

gwy_data_field_area_fill ()

void
gwy_data_field_area_fill (GwyDataField *data_field,
                          gint col,
                          gint row,
                          gint width,
                          gint height,
                          gdouble value);

Fills a rectangular part of a data field with given value.

gwy_data_field_area_fill_mask ()

void
gwy_data_field_area_fill_mask (GwyDataField *data_field,
                               GwyDataField *mask,
                               GwyMaskingType mode,
                               gint col,
                               gint row,
                               gint width,
                               gint height,
                               gdouble value);

Fills a masked rectangular part of a data field with given value.

Since: 2.44

gwy_data_field_area_clear ()

void
gwy_data_field_area_clear (GwyDataField *data_field,
                           gint col,
                           gint row,
                           gint width,
                           gint height);

Fills a rectangular part of a data field with zeroes.

gwy_data_field_area_multiply ()

void
gwy_data_field_area_multiply (GwyDataField *data_field,
                              gint col,
                              gint row,
                              gint width,
                              gint height,
                              gdouble value);

Multiplies values in a rectangular part of a data field by given value

gwy_data_field_area_add ()

void
gwy_data_field_area_add (GwyDataField *data_field,
                         gint col,
                         gint row,
                         gint width,
                         gint height,
                         gdouble value);

Adds given value to all values in a rectangular part of a data field.

gwy_data_field_area_abs ()

void
gwy_data_field_area_abs (GwyDataField *data_field,
                         gint col,
                         gint row,
                         gint width,
                         gint height);

Takes absolute value of values in a rectangular part of a data field.

Since: 2.52

gwy_data_field_get_profile ()

GwyDataLine *
gwy_data_field_get_profile (GwyDataField *data_field,
                            GwyDataLine *data_line,
                            gint scol,
                            gint srow,
                            gint ecol,
                            gint erow,
                            gint res,
                            gint thickness,
                            GwyInterpolationType interpolation);

Extracts a possibly averaged profile from data field to a data line.

gwy_data_field_get_profile_mask ()

GwyXY *
gwy_data_field_get_profile_mask (GwyDataField *data_field,
                                 gint *ndata,
                                 GwyDataField *mask,
                                 GwyMaskingType masking,
                                 gdouble xfrom,
                                 gdouble yfrom,
                                 gdouble xto,
                                 gdouble yto,
                                 gint res,
                                 gint thickness,
                                 GwyInterpolationType interpolation);

Extracts a possibly averaged profile from data field, with masking.

The extracted profile can contain holes due to masking. It can also contain no points at all if the all data values along the profile were excluded due to masking – in this case NULL is returned.

Unlike gwy_data_field_get_profile(), this function takes real coordinates (without offsets), not row and column indices.

Since: 2.49

gwy_data_field_get_row ()

void
gwy_data_field_get_row (GwyDataField *data_field,
                        GwyDataLine *data_line,
                        gint row);

Extracts a data field row into a data line.

gwy_data_field_get_column ()

void
gwy_data_field_get_column (GwyDataField *data_field,
                           GwyDataLine *data_line,
                           gint col);

Extracts a data field column into a data line.

gwy_data_field_set_row ()

void
gwy_data_field_set_row (GwyDataField *data_field,
                        GwyDataLine *data_line,
                        gint row);

Sets a row in the data field to values of a data line.

Data line length must be equal to width of data field.

gwy_data_field_set_column ()

void
gwy_data_field_set_column (GwyDataField *data_field,
                           GwyDataLine *data_line,
                           gint col);

Sets a column in the data field to values of a data line.

Data line length must be equal to height of data field.

gwy_data_field_get_row_part ()

void
gwy_data_field_get_row_part (GwyDataField *data_field,
                             GwyDataLine *data_line,
                             gint row,
                             gint from,
                             gint to);

Extracts part of a data field row into a data line.

gwy_data_field_get_column_part ()

void
gwy_data_field_get_column_part (GwyDataField *data_field,
                                GwyDataLine *data_line,
                                gint col,
                                gint from,
                                gint to);

Extracts part of a data field column into a data line.

gwy_data_field_set_row_part ()

void
gwy_data_field_set_row_part (GwyDataField *data_field,
                             GwyDataLine *data_line,
                             gint row,
                             gint from,
                             gint to);

Puts a data line into a data field row.

If data line length differs from to -from , it is resampled to this length.

gwy_data_field_set_column_part ()

void
gwy_data_field_set_column_part (GwyDataField *data_field,
                                GwyDataLine *data_line,
                                gint col,
                                gint from,
                                gint to);

Puts a data line into data field column.

If data line length differs from to -from , it is resampled to this length.

gwy_data_field_get_xder ()

gdouble
gwy_data_field_get_xder (GwyDataField *data_field,
                         gint col,
                         gint row);

Computes central derivative in X direction.

On border points, one-side derivative is returned.

gwy_data_field_get_yder ()

gdouble
gwy_data_field_get_yder (GwyDataField *data_field,
                         gint col,
                         gint row);

Computes central derivative in Y direction.

On border points, one-side derivative is returned.

Note the derivative is for legacy reasons calulcated for the opposite y direction than is usual elsewhere in Gwyddion, i.e. if values increase with increasing row number, the returned value is negative.

gwy_data_field_get_angder ()

gdouble
gwy_data_field_get_angder (GwyDataField *data_field,
                           gint col,
                           gint row,
                           gdouble theta);

Computes derivative in direction specified by given angle.

gwy_data_field_average_xyz ()

void
gwy_data_field_average_xyz (GwyDataField *data_field,
                            GwyDataField *density_map,
                            const GwyXYZ *points,
                            gint npoints);

Fills a data field with regularised XYZ data using a simple method.

The real dimensions and offsets of field determine the rectangle in the XY plane that will be regularised. The regularisation method is fast but simple and there are no absolute guarantees of quality, even though the result will be usually quite acceptable.

This especially applies to reasonable views of the XYZ data. Unreasonable views can be rendered unreasonably. In particular if the rectangle does not contain any point from points (either due to high zoom to an empty region or by just being completely off) data_field will be filled entirely with the value of the closest point or something similar.

Since: 2.44

gwy_data_field_get_xmeasure

#define gwy_data_field_get_xmeasure gwy_data_field_get_dx

Alias for gwy_data_field_get_dx().

gwy_data_field_get_ymeasure

#define gwy_data_field_get_ymeasure gwy_data_field_get_dy

Alias for gwy_data_field_get_dy().

struct GwyDataField

struct GwyDataField;

The GwyDataField struct contains private data only and should be accessed using the functions below.

struct GwyDataFieldClass

struct GwyDataFieldClass {
    GObjectClass parent_class;

    void (*data_changed)(GwyDataField *data_field);
};

The “data-changed” signal

void
user_function (GwyDataField *gwydatafield,
               gpointer      user_data)

The ::data-changed signal is never emitted by data field itself. It is intended as a means to notify others data field users they should update themselves.

Flags: Run First