R/col.persp3d.R

In fzwaeustc/pcrfn: Peng's Collection of R Functions at Nielsen

col.persp3d <-
function(z, colfun, ncol=12, colcoe=1,
                          colrange=range(z, na.rm=T),...){
    #ncol: The number of color you use if colcoe=1;
    #colcoe: some sort of expanding factor. If you are using topo.colors, you may 
    #don't want to use the full range of topo colors. Using colcoe>1
    #will enable some truncation at the lower spectrum of topo.colors.
    #see the tail function below;
    #colrange: The real range of the z value to which these colors are mapped
    #it may be larger than the actual range of Z values, as you can expect.
    
#     ncol=12
#     colcoe=1
#     z=p_norm_100_mat
#     colrange=range(z, na.rm=T)
#     colfun=brewer.pal
    
    #require(RColorBrewer)
    
    if(class(colfun)!="function") 
      stop("A color scheme function is needed for col.persp3d, such as
           topo.colors, or brewer.pal")
    
    ncolor <- ncol
    
    funmatch <- match.fun(colfun)

    pre_colors <- funmatch(trunc(colcoe* ncolor), ...)
    
    couleurs  <- tail(pre_colors,ncolor)
    zlim <- colrange
    nrz <- nrow(z)
    ncz <- ncol(z)
    col <- couleurs[trunc((z-zlim[1])
                                /(zlim[2]-zlim[1])*(ncol-1))+1]
    return(col)    
  }