Draw Operations 7-9
SHADE( (DRAW DRAW, item 8) shades the area on a graph
that is below one specified function and above another,
between two X values. SHADE( is not an interactive operation.
It draws lowerfunc and upperfunc in terms of X on the
current graph and shades the area that is specifically above
lowerfunc and below upperfunc. Only the areas where
lowerfunc < upperfunc are shaded.
You can specify the shading resolution (an integer between 1
and 9). If none is specified, 1 is used. resolution=1 shades
every pixel. resolution=2 shades every second pixel.
resolution=3 shades every third pixel, and so on.
Optionally, you can specify Xleft (the left boundary) and
Xright (the right boundary) for the shaded area. If Xleft or
Xright is not specified, XMIN and XMAX are used.
SHADE(lowerfunc,upperfunc)
SHADE(lowerfunc,upperfunc,resolution)
SHADE(lowerfunc,upperfunc,resolution,Xleft)
SHADE(lowerfunc,upperfunc,resolution,Xleft,Xright)
Shading a Graph