velvect -- two dimensional velocity field plot
velvect uimage vimage
Task velvect draws a representation of a two-dimensional velocity field by drawing arrows from each data location. The length of the arrow is proportional to the strength of the field at that location and the direction of the arrow indicates the direction of the flow at that location. The two images uimage and vimage contain the velocity field to be plotted. The vector at the point (i,j) has:
magnitude = sqrt (uimage(i,j)**2 + vimage(i,j)**2) direction = atan2 (vimage(i,j), uimage(i,j))
1. Make a vector plot from the two images "crab.blue" and "crab.red".
cl> velvect crab.blue crab.red