The PLOT_FIELD procedure plots a 2D field. N random points are picked, and from each point a path is traced along the field. The length of the path is proportional to the field vector magnitude.
This routine is written in the IDL language. Its source code can be found in the file
plot_field.pro
in the
lib
subdirectory of the IDL distribution.
Set this keyword to the aspect ratio of the plot (i.e., the ratio of the X size to Y size). The default is 1.0.