# colorbar

draw a colorbar

## Calling Sequence

    colorbar(umin, umax [, colminmax, fmt])

## Arguments

umin

  real scalar, the minimum value associated with the plot

umax

  real scalar, the maximum value associated with the plot

colminmax

  (optional) a vector with 2 integer components

fmt

  (optional) a string to set up the display format for colorbar graduations

## Description

Draw a colorbar for a plot3d, fec, Sgrayplot, etc... The function may be called BEFORE the plot3d, fec, Sgrayplot,... because its sets and changes the frame for the plot. This way the colorbar is not part of the associated plot and so is not modified by a zoom or a rotation.

The optional argument `colminmax` may be used to precise the first color (associated with umin) and the last color (associated with umax) of the current colormap. By default `colminmax=[1 nb_colors]` where nb_colors is the number of colors of the current colormap.

The optional argument `fmt` is a string containing a C-format, like `"%.2f"`, `"%e"`, etc...

For the 2 optional arguments you can use the syntax `keyword=value` (see the last example).

## Examples

    // example 1
    x = linspace(0,1,81);
    z = cos(2*%pi*x)'*sin(2*%pi*x);
    zm = min(z); zM = max(z);
    clf()
    xset("colormap",jetcolormap(64))
    colorbar(zm,zM)
    Sgrayplot(x,x,z)
    xtitle("The function cos(2 pi x)sin(2 pi y)")

// example 1 x = linspace(0,1,81); z = cos(2*%pi*x)'*sin(2*%pi*x); zm = min(z); zM = max(z); clf() xset("colormap",jetcolormap(64)) colorbar(zm,zM) Sgrayplot(x,x,z) xtitle("The function cos(2 pi x)sin(2 pi y)")

    // example 2
    x = linspace(0,1,81);
    z = cos(2*%pi*x)'*sin(2*%pi*x);
    zm = min(z); zM = max(z);
    zz = abs(0.5*cos(2*%pi*x)'*cos(2*%pi*x));
    zzm = min(zz); zzM = max(zz);
    clf();
    xset("colormap",jetcolormap(64))

    drawlater() ;
    subplot(2,2,1)
       colorbar(zm,zM)
       Sgrayplot(x,x,z, strf="031", rect=[0 0 1 1])
       xtitle("a Sgrayplot with a colorbar")
    subplot(2,2,2)
       colorbar(zm,zM)
       plot3d1(x,x,z)
       xtitle("a plot3d1 with a colorbar")
    subplot(2,2,3)
       colorbar(zzm,zzM)
       plot3d1(x,x,zz)
       xtitle("a plot3d1 with a colorbar")
    subplot(2,2,4)
       colorbar(zzm,zzM)
       Sgrayplot(x,x,zz, strf="031", rect=[0 0 1 1])
       xtitle("a Sgrayplot with a colorbar")
    drawnow() ;

x = linspace(0,1,81); z = cos(2*%pi*x)'*sin(2*%pi*x); zm = min(z); zM = max(z); zz = abs(0.5*cos(2*%pi*x)'*cos(2*%pi*x)); zzm = min(zz); zzM = max(zz); clf(); xset("colormap",jetcolormap(64)) drawlater(); subplot(2,2,1) colorbar(zm,zM) Sgrayplot(x,x,z, strf="031", rect=[0 0 1 1]) xtitle("a Sgrayplot with a colorbar") subplot(2,2,2) colorbar(zm,zM) plot3d1(x,x,z) xtitle("a plot3d1 with a colorbar") subplot(2,2,3) colorbar(zzm,zzM) plot3d1(x,x,zz) xtitle("a plot3d1 with a colorbar") subplot(2,2,4) colorbar(zzm,zzM) Sgrayplot(x,x,zz, strf="031", rect=[0 0 1 1]) xtitle("a Sgrayplot with a colorbar") drawnow() ;

    // example 3
    x = linspace(0,1,81);
    zz = abs(0.5*cos(2*%pi*x)'*cos(2*%pi*x));
    zzm = min(zz); zzM = max(zz);
    [xf,yf,zf]=genfac3d(x,x,zz);
    nb_col = 64;
    clf()
    xset("colormap",hotcolormap(nb_col))
    drawlater() ;
    colorbar(zzm,zzM,[1, nb_col],fmt="%.1f")
    nbcol = xget("lastpattern")
    zcol = dsearch(zf, linspace(zzm, zzM, nb_col+1));
    plot3d(xf, yf, list(zf, zcol), flag = [-2 6 4])
    xtitle("a plot3d with shaded interpolated colors")
    drawnow() ;
    show_window()

x = linspace(0,1,81); zz = abs(0.5*cos(2*%pi*x)'*cos(2*%pi*x)); zzm = min(zz); zzM = max(zz); [xf,yf,zf]=genfac3d(x,x,zz); nb_col = 64; xset("colormap",hotcolormap(nb_col)) colorbar(zzm,zzM,[1, nb_col],fmt="%.1f") nbcol = xget("lastpattern") zcol = dsearch(zf, linspace(zzm, zzM, nb_col+1)); plot3d(xf, yf, list(zf, zcol), flag = [-2 6 4]) xtitle("a plot3d with shaded interpolated colors")

## See Also

- colormap