diff options
Diffstat (limited to 'pkg/plot/doc/velvect.hlp')
| -rw-r--r-- | pkg/plot/doc/velvect.hlp | 47 |
1 files changed, 47 insertions, 0 deletions
diff --git a/pkg/plot/doc/velvect.hlp b/pkg/plot/doc/velvect.hlp new file mode 100644 index 00000000..43b73cfb --- /dev/null +++ b/pkg/plot/doc/velvect.hlp @@ -0,0 +1,47 @@ +.help velvect Sep85 plot +.ih +NAME +velvect -- two dimensional velocity field plot +.ih +USAGE +velvect uimage vimage +.ih +PARAMETERS +.ls uimage +Name of image containing u components of the velocity field. +.le +.ls vimage +Name of image containing v components of the velocity field. +.le +.ls device = stdgraph +Output device for plot. +.le +.ls title = "imtitle" +Title to be centered over the plot. By default, it will be the title +from the image header of the \fBuimage\fR. +.le +.ls append = no +Append to an old plot? +.le +.ls verbose = yes +Print warning messages? +.le +.ih +DESCRIPTION +Task \fIvelvect\fR 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 \fIuimage\fR and \fIvimage\fR contain the velocity field to be +plotted. The vector at the point (i,j) has: + +.nf + magnitude = sqrt (uimage(i,j)**2 + vimage(i,j)**2) + direction = atan2 (vimage(i,j), uimage(i,j)) +.fi +.ih +EXAMPLES +1. Make a vector plot from the two images "crab.blue" and "crab.red". + + cl> velvect crab.blue crab.red +.endhelp |