Graphics

• 2- and 3-D plots of curves and surfaces.
• Use plot for 2-D functions.
• For $y = cos x$ and $y = cos^2x$ over $[0, \pi]$:

  >>x=0:0.1:pi; %(step-size = 0.1)
  >>y=cos(x);
  >>z=cos(x).^2;
  >>plot(x,y,x,z,'o') %(o's at (x_k, z_k))
  

• Function plot. fplot('name', [a,b],n) plots function name with n points (default 25) in interval of [a, b].

  
• plot and plot3 for parametric curves in 2- and 3-D space.
  • Ellipse $c(t) = (2 cos t, 3 sin t), t \in [0, 2\pi]$:

    
  • Curve $c(t) = (2 cos t, t^2, 1/t), t \in [0.1, 4\pi]$:

    
• 3-D surface plots, specify a rectangular subset of the domain of a function with meshgrid, mesh or surf.

  >>x=-pi:0.1:pi;
  >>y=x;
  >>[x,y]=meshgrid(x,y);
  >>z=sin(cos(x+y));
  >>mesh(z)
  

  >>help plot
  >>help fplot
  >>help plot3
  >>help mesh
  >>help meshgrid