PLSCMAP1A(3plplot) | PLplot API | PLSCMAP1A(3plplot) |

# NAME¶

**plscmap1a** - Set semitransparent cmap1 RGBA colors.

# SYNOPSIS¶

**plscmap1a**(*r*, *g*, *b*, *alpha*,
*ncol1*)

# DESCRIPTION¶

Set semitransparent cmap1 colors (see the PLplot documentation)
using RGBA vector values. This function also sets the number of cmap1
colors. N.B. Continuous cmap1 colors are indexed with a floating-point index
in the range from 0.0-1.0 which is linearly transformed (e.g., by
**plcol1**(3plplot)) to an integer index of these RGBA vectors in the
range from 0 to *ncol1-1*. So in order for this continuous color model
to work properly, it is the responsibility of the user of
**plscmap1**(3plplot) to insure that these RGBA vectors are continuous
functions of their integer indices.

Redacted form: **plscmap1a(r, g, b, alpha)**

This function is used in example 31.

# ARGUMENTS¶

*r*(**PLINT_VECTOR**(3plplot), input)- A vector that represents (using unsigned 8-bit integers in the range from 0-255) the degree of red in the color as a continuous function of the integer index of the vector.
*g*(**PLINT_VECTOR**(3plplot), input)- A vector that represents (using unsigned 8-bit integers in the range from 0-255) the degree of green in the color as a continuous function of the integer index of the vector.
*b*(**PLINT_VECTOR**(3plplot), input)- A vector that represents (using unsigned 8-bit integers in the range from 0-255) the degree of blue in the color as a continuous function of the integer index of the vector.
*alpha*(**PLFLT_VECTOR**(3plplot), input)- A vector that represents (using PLFLT values in the range from 0.0-1.0 where 0.0 corresponds to completely transparent and 1.0 corresponds to completely opaque) the alpha transparency of the color as a continuous function of the integer index of the vector.
*ncol1*(**PLINT**(3plplot), input)- Number of items in the
*r*,*g*,*b*, and*alpha*vectors.

# AUTHORS¶

Many developers (who are credited at http://plplot.org/credits.php) have contributed to PLplot over its long history.

# SEE ALSO¶

PLplot documentation at http://plplot.org/documentation.php.

August, 2021 |