tip: Gwyddion Data Processing Library Reference Manual

## tip tip — SPM tip methods |

## Functions

void | (*GwyTipModelFunc) ()
void | (*GwyTipGuessFunc) ()
gint | gwy_tip_model_get_npresets ()
const GwyTipModelPreset * | gwy_tip_model_get_preset ()
const GwyTipModelPreset * | gwy_tip_model_get_preset_by_name ()
gint | gwy_tip_model_get_preset_id ()
const gchar * | gwy_tip_model_get_preset_tip_name ()
const gchar * | gwy_tip_model_get_preset_group_name ()
gint | gwy_tip_model_get_preset_nparams ()
const GwyTipParamType * | gwy_tip_model_get_preset_params ()
void | gwy_tip_model_preset_create ()
void | gwy_tip_model_preset_create_for_zrange ()
GwyDataField * | gwy_tip_dilation ()
GwyDataField * | gwy_tip_erosion ()
GwyDataField * | gwy_tip_cmap ()
GwyDataField * | gwy_tip_estimate_partial ()
GwyDataField * | gwy_tip_estimate_full ()

## Types and Values

struct | GwyTipModelPreset

## Object Hierarchy

        gpointer
        ╰── GwyTipModelPreset

## Includes

    #include <libprocess/gwyprocess.h>

## Description

## Functions

### GwyTipModelFunc ()

    void
    (*GwyTipModelFunc) (GwyDataField *tip,
                        gdouble height,
                        gdouble radius,
                        gdouble rotation,
                        gdouble *params);

`GwyTipModelFunc` is deprecated and should not be used in newly-written code.

### GwyTipGuessFunc ()

    void
    (*GwyTipGuessFunc) (GwyDataField *data,
                        gdouble height,
                        gdouble radius,
                        gdouble *params,
                        gint *xres,
                        gint *yres);

`GwyTipGuessFunc` is deprecated and should not be used in newly-written code.

### gwy_tip_model_get_npresets ()

    gint
    gwy_tip_model_get_npresets (void);

Find number of actual tip model presets.

#### Returns

Number of presets.

### gwy_tip_model_get_preset ()

    const GwyTipModelPreset *
    gwy_tip_model_get_preset (gint preset_id);

Get data related to tip preset.

#### Parameters

preset_id | Preset identifier. |

#### Returns

Chosen preset data.

### gwy_tip_model_get_preset_by_name ()

    const GwyTipModelPreset *
    gwy_tip_model_get_preset_by_name (const gchar *name);

Get data related to preset with specified name.

#### Parameters

name | Name of tip (e. g. "contact"). |

#### Returns

Chosen preset data.

### gwy_tip_model_get_preset_id ()

    gint
    gwy_tip_model_get_preset_id (const GwyTipModelPreset *preset);

Get preset identifier within all presets.

#### Parameters

preset | Tip model preset. |

#### Returns

Preset id.

### gwy_tip_model_get_preset_tip_name ()

    const gchar *
    gwy_tip_model_get_preset_tip_name (const GwyTipModelPreset *preset);

Get name of the preset (e. g. "contact").

#### Parameters

preset | Tip model preset. |

#### Returns

Preset name.

### gwy_tip_model_get_preset_group_name ()

    const gchar *
    gwy_tip_model_get_preset_group_name (const GwyTipModelPreset *preset);

Get group name of preset (e. g. "analytical".)

#### Parameters

preset | Tip model preset. |

#### Returns

Preset group name.

### gwy_tip_model_get_preset_nparams ()

    gint
    gwy_tip_model_get_preset_nparams (const GwyTipModelPreset *preset);

Get number of tip preset parameters.

In versions prior to 2.47 the function alwas returned zero and thus was useless. You had to know the what parameters each model had and always pass a maximum-nparams-sized array with only the interesting elements containing your parameters. Since version 2.47 it returns the true number of parameters used in functions such as `gwy_tip_model_preset_create()` and `gwy_tip_model_preset_create_for_zrange()`. It does not return the number of parameters the old functions take. They behave exactly as before.

#### Parameters

preset | Tip model preset. |

#### Returns

Number of parameters.

### gwy_tip_model_get_preset_params ()

    const GwyTipParamType *
    gwy_tip_model_get_preset_params (const GwyTipModelPreset *preset);

Gets the list of parameters of a tip model preset.

All tip models have parameters from a predefined set given by the GwyTipParamType enum.

Note further items may be in principle added to the set in the future so you may want to avoid tip models that have parameters with an unknown (higher than known) id.

#### Parameters

preset | Tip model preset. |

#### Returns

List of all tip model parameter ids in ascending order. The array is owned by the library and must not be modified nor freed.

Since: 2.47

### gwy_tip_model_preset_create ()

    void
    gwy_tip_model_preset_create (const GwyTipModelPreset *preset,
                                 GwyDataField *tip,
                                 const gdouble *params);

Fills a data field with a preset tip model.

Both pixel and physical dimensions of the `tip` data field are preserved by this function. Ensure that before using this function the `tip` data field has the same pixels as target data field you want to use the tip model with.

The number of parameters is the true full number of parameters as reported by `gwy_tip_model_get_preset_nparams()` and `gwy_tip_model_get_preset_params()`. And only those parameters are passed in `params` .

#### Parameters

preset | Tip model preset. |
tip | Data field to fill with the tip model. |
params | Parameters of the tip model. |

Since: 2.47

### gwy_tip_model_preset_create_for_zrange ()

    void
    gwy_tip_model_preset_create_for_zrange
                                   (const GwyTipModelPreset *preset,
                                    GwyDataField *tip,
                                    gdouble zrange,
                                    gboolean square,
                                    const gdouble *params);

Fills a data field with a preset tip model, resizing it to make it suitable for the given value range.

The dimensions of a pixel in `tip` is preserved by this function. Ensure that before using this function the `tip` data field has the same pixels as target data field you want to use the tip model with.

However, its dimensions will generally be changed to ensure it is optimal for `zrange` . This means it is guaranteed the height difference between the apex and any border pixel in `tip` is at least `zrange` , while simultaneously the smallest such difference is not much larger than `zrange` .

The number of parameters is the true full number of parameters as reported by `gwy_tip_model_get_preset_nparams()` and `gwy_tip_model_get_preset_params()`. And only those parameters are passed in `params` .

#### Parameters

preset | Tip model preset. |
tip | Data field to fill with the tip model. |
zrange | Range of height values in the data determining the required height of the tip model. |
square | `TRUE` to enforce a square data field (with `xres` and `yres` equal). |
params | Parameters of the tip model. |

Since: 2.47

### gwy_tip_dilation ()

    GwyDataField *
    gwy_tip_dilation (GwyDataField *tip,
                      GwyDataField *surface,
                      GwyDataField *result,
                      GwySetFractionFunc set_fraction,
                      GwySetMessageFunc set_message);

Performs the tip convolution algorithm published by Villarrubia, which is equivalent to morphological dilation operation.

If the operation is aborted the size and contents of `result` field is undefined.

#### Parameters

tip | Tip data. |
surface | Surface data. |
result | Data field where to store dilated surface to. |
set_fraction | Function that sets fraction to output (or `NULL`). |
set_message | Function that sets message to output (or `NULL`). |

#### Returns

Dilated surface data, i.e. `result` , on success. May return `NULL` if aborted.

### gwy_tip_erosion ()

    GwyDataField *
    gwy_tip_erosion (GwyDataField *tip,
                     GwyDataField *surface,
                     GwyDataField *result,
                     GwySetFractionFunc set_fraction,
                     GwySetMessageFunc set_message);

Performs surface reconstruction (erosion) algorithm published by Villarrubia, which is equivalent to morphological erosion operation.

If the operation is aborted the size and contents of `result` field is undefined.

#### Parameters

tip | Tip data. |
surface | Surface to be eroded. |
result | Data field where to store dilated surface to. |
set_fraction | Function that sets fraction to output (or `NULL`). |
set_message | Function that sets message to output (or `NULL`). |

#### Returns

Reconstructed (eroded) surface, i.e. `result` , on success. May return `NULL` if aborted.

### gwy_tip_cmap ()

    GwyDataField *
    gwy_tip_cmap (GwyDataField *tip,
                  GwyDataField *surface,
                  GwyDataField *result,
                  GwySetFractionFunc set_fraction,
                  GwySetMessageFunc set_message);

Performs certainty map algorithm published by Villarrubia. This function converts all fields into form requested by "morph_lib.c" library, that is almost identical with original Villarubia's library. Result certainty map can be used as a mask of points where tip did not directly touch the surface.

#### Parameters

tip | Tip data. |
surface | Surface data. |
result | Data field to store ceratainty map data to. |
set_fraction | Function that sets fraction to output (or `NULL`). |
set_message | Function that sets message to output (of `NULL`). |

#### Returns

Certainty map, i.e. `result` , on success. May return `NULL` if aborted.

### gwy_tip_estimate_partial ()

    GwyDataField *
    gwy_tip_estimate_partial (GwyDataField *tip,
                              GwyDataField *surface,
                              gdouble threshold,
                              gboolean use_edges,
                              gint *count,
                              GwySetFractionFunc set_fraction,
                              GwySetMessageFunc set_message);

Performs partial blind estimation algorithm published by Villarrubia. This function converts all fields into form requested by "morph_lib.c" library, that is almost identical with original Villarubia's library. Note that the threshold value must be chosen sufficently high value to supress small fluctulations due to noise (that would lead to very sharp tip) but sufficiently low value to put algorithm at work. A value similar to 1/10000 of surface range can be good. Otherwise we recommend to start with zero threshold and increase it slowly to observe changes and choose right value.

#### Parameters

tip | Tip data to be refined (allocated). |
surface | Surface data. |
threshold | Threshold for noise supression. |
use_edges | Whether use also edges of image. |
count | Where to store the number of places that produced refinements to. |
set_fraction | Function that sets fraction to output (or `NULL`). |
set_message | Function that sets message to output (or `NULL`). |

#### Returns

Estimated tip. May return `NULL` if aborted.

### gwy_tip_estimate_full ()

    GwyDataField *
    gwy_tip_estimate_full (GwyDataField *tip,
                           GwyDataField *surface,
                           gdouble threshold,
                           gboolean use_edges,
                           gint *count,
                           GwySetFractionFunc set_fraction,
                           GwySetMessageFunc set_message);

Performs full blind estimation algorithm published by Villarrubia. This function converts all fields into form requested by "morph_lib.c" library, that is almost identical with original Villarubia's library. Note that the threshold value must be chosen sufficently high value to supress small fluctulations due to noise (that would lead to very sharp tip) but sufficiently low value to put algorithm at work. A value similar to 1/10000 of surface range can be good. Otherwise we recommend to start with zero threshold and increase it slowly to observe changes and choose right value.

#### Parameters

tip | Tip data to be refined (allocated). |
surface | Surface data. |
threshold | Threshold for noise supression. |
use_edges | Whether use also edges of image. |
count | Where to store the number of places that produced refinements to. |
set_fraction | Function that sets fraction to output (or `NULL`). |
set_message | Function that sets message to output (or `NULL`). |

#### Returns

Estimated tip. May return `NULL` if aborted.

## Types and Values

### struct GwyTipModelPreset

    struct GwyTipModelPreset;

`GwyTipModelPreset` is deprecated and should not be used in newly-written code.