IDL vector filed plot

The VELOVECT procedure produces a two-dimensional velocity field plot. A directed arrow is drawn at each point showing the direction and magnitude of the field.

This routine is written in the IDL language. Its source code can be found in the file velovect.pro in the lib subdirectory of the IDL distribution.

Examples

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; Create some random data:U = RANDOMN(S, 20, 20)V = RANDOMN(S, 20, 20); Plot the vector field:VELOVECT, U, V; Plot the field, using dots to represent vectors with values ; greater than 18:VELOVECT, U, V, MISSING=18, /DOTS; Plot with a title. Note that the XTITLE keyword is passed; directly to the PLOT procedure:VELOVECT, U, V, MISSING=18, /DOTS, XTITLE='Random Vectors'

Syntax

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VELOVECT, U, V [, X, Y] [, COLOR=index] [, MISSING=value [, /DOTS]] [, LENGTH=value] [, /OVERPLOT] [Also accepts all PLOT keywords]

Arguments

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U

The X component of the two-dimensional field. U must be a two-dimensional array.

V

The Y component of the two dimensional field. V must have the same dimensions as U.

X

Optional abscissae values. X must be a vector with a length equal to the first dimension of U and V.

Y

Optional ordinate values. Y must be a vector with a length equal to the second dimension of U and V.