| 
            plscmap1a
          ( | r , | 
| g , | |
| b , | |
| alpha , | |
| ncol1 ); | 
      Set semitransparent cmap1 colors (see the section called “Color Map1”)
      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) 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 to insure that these RGBA
      vectors are continuous functions of their integer indices.
    
r
          (PLINT_VECTORA 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_VECTORA 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_VECTORA 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_VECTORA 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
            Number of items in the
            
              ,
            r
            
              ,
            g
            
              , and
            b
            
               vectors.
          alpha
            
      Redacted form: plscmap1a(r, g, b, alpha)
    
This function is used in example 31.