# plvect.3plplot man page

**plvect** — Vector plot

## Synopsis

**plvect**(*u*, *v*, *nx*, *ny*, *scale*, *pltr*, *pltr_data*)

## Description

Draws a vector plot of the vector (*u*[*nx*][*ny*],*v*[*nx*][*ny*]) . The scaling factor for the vectors is given by *scale*. A transformation routine pointed to by *pltr* with a pointer *pltr_data* for additional data required by the transformation routine is used to map indices within the array to the world coordinates. The style of the vector arrow may be set using **plsvect**(3plplot).

Redacted form: **plvect(u, v, scale, pltr, pltr_data)**

This function is used in example 22.

## Arguments

*u, v*(const PLFLT * const *, input)- Pointers to a pair of vectored two-dimensional arrays containing the x and y components of the vector data to be plotted.
*nx, ny*(PLINT, input)- Physical dimensions of the arrays
*u*and*v*. *scale*(PLFLT, input)- Parameter to control the scaling factor of the vectors for plotting. If
*scale*= 0 then the scaling factor is automatically calculated for the data. If*scale*< 0 then the scaling factor is automatically calculated for the data and then multiplied by -*scale*. If*scale*> 0 then the scaling factor is set to*scale*. *pltr*(void (*) (PLFLT, PLFLT, PLFLT *, PLFLT *, PLPointer) , input)- Pointer to function that defines transformation between indices in array
*z*and the world coordinates (C only). Transformation functions are provided in the PLplot library:**pltr0**(3plplot) for identity mapping, and**pltr1**(3plplot) and**pltr2**(3plplot) for arbitrary mappings respectively defined by one- and two-dimensional arrays. In addition, user-supplied routines for the transformation can be used as well. Examples of all of these approaches are given in the PLplot documentation. The transformation function should have the form given by any of**pltr0**(3plplot),**pltr1**(3plplot), or**pltr2**(3plplot). *pltr_data*(PLPointer, input)- Extra parameter to help pass information to
**pltr0**(3plplot),**pltr1**(3plplot),**pltr2**(3plplot), or whatever routine that is externally supplied.

## Authors

Many developers (who are credited at http://plplot.sourceforge.net/credits.p…) have contributed to PLplot over its long history.

## See Also

PLplot documentation at http://plplot.sourceforge.net/documenta….

## Info

PLplot API August, 2015