Advanced Programming Guide

6.3 Maple Plotting Data Structures • 225Figure 6.1 How plots are displayedExamplesYou can assign the plotting data structures to variables, transform theminto other structures, save them, or print them.You can see examples of a plot structure in either two- or threedimensionsby line printing such a structure.> lprint( plot(2*x+3, x=0..5, numpoints=3, adaptive=false) );PLOT(CURVES([[0., 3.], [2.61565849999999989, 8.2313170\0000000066], [5., 13.]],COLOUR(RGB,1.0,0.,0.)),AXESLABELS("x",""),VIEW(0. .. 5.,DEFAULT))Here, plot generates a PLOT data structure that includes theinformation for a single curve defined by three points. The curve is coloredwith RGB values (1.0, 0, 0), which correspond to red. The plot has ahorizontal axis running from 0 to 5. Maple, by default, determines thescale along the vertical axes using the information that you provide inthe vertical components of the curve. The numpoints = 3 and adaptive= false settings ensure that the curve consists of only three points.The second example is the graph of z = xy over a 3 × 4 grid. ThePLOT3D structure contains a grid of z values over the rectangular region[0, 1] × [0, 2].> lprint( plot3d(x*y, x=0..1, y=0..2, grid=[3,4]) );PLOT3D(GRID(0. .. 1.,0. .. 2.,Array(1 .. 3,1 .. 4,{(2,2) = .333333333333333314, (2, 3) = .666666666666666629, (2, 4) = 1., (3, 2) = .666666666666666629, (3, 3) =1.33333333333333326, (3, 4) = 2.},datatype = float[8],storage = rectangular,order = C_order)),AXESLABELS(x,y,""))The structure includes labels x and y for the plane but no labelfor the z-axis.