In this section:
The following code is extracted from program simdem10.f95 in the Simdem package, and it illustrates how easy it is to plot a curve in the parametric form x = x(t), y = y(t), where x and y are double precision arrays. Of course, the arrays x, and y do not need to be in parameteric form, and any number of up to 4 x,y pairs in the form y = f(x) can be plotted. Setting l(i) = m(i) = 0 suppresses the plotting of y(i).
! ! Define line and symbol types and number of points ! l1 = 1 !solid line type l2 = 2 !dashed line type l3 = 3 !dotted line type l4 = 4 !dashed-dotted line type m1 = 5 !circle symbol type m2 = 8 !triangle symbol type m3 = 11 !square symbol type m4 = 14 !diamond symbol type n = nmax/2 !number of points for plotting n1 = n n2 = n n3 = n n4 = n ! ! Define the data ! delta = pi2/(dble(n) - one) t(1) = zero do i = 2, n - 1 t(i) = t(i - 1) + delta enddo t(n) = pi2 do i = 1, n cosi = cos(t(i)) sini = sin(t(i)) x1(i) = a*cosi x2(i) = b*cosi x3(i) = c*cosi x4(i) = d*cosi y1(i) = a*sini y2(i) = b*sini y3(i) = c*sini y4(i) = d*sini enddo ! ! Define the title and legends ! ptitle = 'y = f(x)' xtitle = 'x' ytitle = 'y' ! ! Plot the graphs ! call gks004 (l1, l2, l3, l4, & m1, m2, m3, m4, & n1, n2, n3, n4, & x1, x2, x3, x4, & y1, y2, y3, y4, & ptitle, xtitle, ytitle, & axes, gsave)
The following plot is then displayed and can be edited to add further features, printed, or archived as a graphics file.