plscmap1la.3plplot man page
plscmap1la — Set cmap1 colors and alpha transparency using a piece-wise linear relationship
plscmap1la(itype, npts, intensity, coord1, coord2, coord3, alpha, alt_hue_path)
This is a variant of plscmap1l(3plplot) that supports alpha channel transparency. It sets cmap1 colors using a piece-wise linear relationship between cmap1 intensity index (from 0. to 1.) and position in HLS or RGB color space (see the PLplot documentation) with alpha transparency value (0.0 - 1.0). It may be called at any time.
Redacted form: plscmap1la(itype, intensity, coord1, coord2, coord3, alpha, alt_hue_path)
This function is used in example 30.
- itype (PLBOOL, input)
true: RGB, false: HLS.
- npts (PLINT, input)
number of control points
- intensity (const PLFLT *, input)
position for each control point (between 0.0 and 1.0, in ascending order)
- coord1 (const PLFLT *, input)
first coordinate (H or R) for each control point
- coord2 (const PLFLT *, input)
second coordinate (L or G) for each control point
- coord3 (const PLFLT *, input)
third coordinate (S or B) for each control point
- alpha (const PLFLT *, input)
the alpha transparency value for each control point
- alt_hue_path (const PLBOOL *, input)
alternative interpolation method flag for each control point. (alt_hue_path[i] refers to the interpolation interval between the i and i + 1 control points).
Many developers (who are credited at http://plplot.sourceforge.net/credits.php) have contributed to PLplot over its long history.
PLplot documentation at http://plplot.sourceforge.net/documentation.php.