IRAF help page for package plot, program velvect

from NOAO velvect -- two dimensional velocity field plotUSAGEPARAMETERSDESCRIPTIONEXAMPLES

velvect -- two dimensional velocity field plot

USAGE

velvect uimage vimage

PARAMETERS

uimage

Name of image containing u components of the velocity field.

vimage

Name of image containing v components of the velocity field.

device = stdgraph

Output device for plot.

title = imtitle

Title to be centered over the plot. By default, it will be the title from the image header of the uimage.

append = no

Append to an old plot?

verbose = yes

Print warning messages?

DESCRIPTION

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))

EXAMPLES

EXAMPLES 1. Make a vector plot from the two images "crab.blue" and "crab.red".

cl> velvect crab.blue crab.red

This page automatically generated from the iraf .hlp file. If you would like your local iraf package .hlp files converted into HTML please contact Dave Mills at NOAO.

dmills@noao.edu