### PVECT

Draw proper motion vectors

#### Description:

Draw proper motion vectors on a projection of the celestial sphere. The XCOL and YCOL data areas are assumed to contain positions in radians, the EXCOL and EYCOL data areas are assumed to contain the proper motions in radians per year. It is possible to use the ERSCALE parameter to multiply the the proper motion so that it is correct for a given number of years. (The proper motion in RA is assumed to be $\stackrel{̇}{\alpha }cos\delta$.)

pvect [erscale]

#### Parameters:

##### ERSCALE = _REAL (Read and Write)
The scale factor for multiplying the vectors.

[The value of the global parameter PONGO_ERSCALE is used. If PONGO_ERSCALE is not defined, the default value 1.0 is used.]

If TRUE, the ZCOL values are additionally used to multiply the vectors. [FALSE]