Combine colormapped data values with an illumination intensity map (a.k.a. "hillshade") of the values. Parameters ---------- data : 2D array-like The height values used to generate a shaded map. cmap : `~matplotlib.colors.Colormap`
(self, data, cmap, norm=None, blend_mode='overlay', vmin=None,
vmax=None, vert_exag=1, dx=1, dy=1, fraction=1, **kwargs)
| 3958 | return intensity |
| 3959 | |
| 3960 | def shade(self, data, cmap, norm=None, blend_mode='overlay', vmin=None, |
| 3961 | vmax=None, vert_exag=1, dx=1, dy=1, fraction=1, **kwargs): |
| 3962 | """ |
| 3963 | Combine colormapped data values with an illumination intensity map |
| 3964 | (a.k.a. "hillshade") of the values. |
| 3965 | |
| 3966 | Parameters |
| 3967 | ---------- |
| 3968 | data : 2D array-like |
| 3969 | The height values used to generate a shaded map. |
| 3970 | cmap : `~matplotlib.colors.Colormap` |
| 3971 | The colormap used to color the *data* array. Note that this must be |
| 3972 | a `~matplotlib.colors.Colormap` instance. For example, rather than |
| 3973 | passing in ``cmap='gist_earth'``, use |
| 3974 | ``cmap=plt.get_cmap('gist_earth')`` instead. |
| 3975 | norm : `~matplotlib.colors.Normalize` instance, optional |
| 3976 | The normalization used to scale values before colormapping. If |
| 3977 | None, the input will be linearly scaled between its min and max. |
| 3978 | blend_mode : {'hsv', 'overlay', 'soft'} or callable, optional |
| 3979 | The type of blending used to combine the colormapped data |
| 3980 | values with the illumination intensity. Default is |
| 3981 | "overlay". Note that for most topographic surfaces, |
| 3982 | "overlay" or "soft" appear more visually realistic. If a |
| 3983 | user-defined function is supplied, it is expected to |
| 3984 | combine an (M, N, 3) RGB array of floats (ranging 0 to 1) with |
| 3985 | an (M, N, 1) hillshade array (also 0 to 1). (Call signature |
| 3986 | ``func(rgb, illum, **kwargs)``) Additional kwargs supplied |
| 3987 | to this function will be passed on to the *blend_mode* |
| 3988 | function. |
| 3989 | vmin : float or None, optional |
| 3990 | The minimum value used in colormapping *data*. If *None* the |
| 3991 | minimum value in *data* is used. If *norm* is specified, then this |
| 3992 | argument will be ignored. |
| 3993 | vmax : float or None, optional |
| 3994 | The maximum value used in colormapping *data*. If *None* the |
| 3995 | maximum value in *data* is used. If *norm* is specified, then this |
| 3996 | argument will be ignored. |
| 3997 | vert_exag : number, optional |
| 3998 | The amount to exaggerate the elevation values by when calculating |
| 3999 | illumination. This can be used either to correct for differences in |
| 4000 | units between the x-y coordinate system and the elevation |
| 4001 | coordinate system (e.g. decimal degrees vs. meters) or to |
| 4002 | exaggerate or de-emphasize topography. |
| 4003 | dx : number, optional |
| 4004 | The x-spacing (columns) of the input *elevation* grid. |
| 4005 | dy : number, optional |
| 4006 | The y-spacing (rows) of the input *elevation* grid. |
| 4007 | fraction : number, optional |
| 4008 | Increases or decreases the contrast of the hillshade. Values |
| 4009 | greater than one will cause intermediate values to move closer to |
| 4010 | full illumination or shadow (and clipping any values that move |
| 4011 | beyond 0 or 1). Note that this is not visually or mathematically |
| 4012 | the same as vertical exaggeration. |
| 4013 | **kwargs |
| 4014 | Additional kwargs are passed on to the *blend_mode* function. |
| 4015 | |
| 4016 | Returns |
| 4017 | ------- |