Plotting r = r(θ)

In this section:

• Introduction
• Simfit plotting styles
• Plotting a pie chart
• Plotting a bar chart
• Plotting y = f(x)
• Plotting r = r(θ)
• Plotting x = x(t), y = y(t)
• Plotting x = x(t), y = y(t), z = z(t)
• Plotting z = f(x,y)

The following code is extracted from program simdem64.f95 in the Simdem package, and it illustrates how easy it is to plot a curve in the parametric form r = r(θ), where r and theta are double precision arrays.

!
! calculate r = sin(4*theta)
!
      delta = two*pi/dble(n - 1)
      theta(1) = zero
      do i = 2, n - 1
         theta(i) = theta(i - 1) + delta
      enddo
      theta(n) = two*pi
      do i = 1, n
         r(i) = sin(four*theta(i))
      enddo
!
! plot the 8 leaved rose
!
      call rtplot (n, r, theta)

The following plot is then displayed and can be edited to add further features, printed, or archived as a graphics file.