help for circvplot

Cumulative vector plot for circular data

circvplot varname [if exp] [in range] [, resultant(resultant_options) rotate(#) twoway_options ]


circvplot produces a cumulative vector plot for varname. varname should be a circular variable taking on values between 0 and 360 degrees. Each value of varname is plotted as a unit vector. The vectors are sorted and plotted end to end, by default starting opposite the mean direction. The resultant of the vectors is also shown as an arrow.

The graph will usually best be shown with xsize() and ysize() equal, or nearly so.


resultant() specifies options controlling the rendering of the arrow showing the resultant. In particular, arrowheadfactor(#) specifies that the arrowhead length should be the default length (which is 7% of the resultant length) X a factor of #. Otherwise, such options are typically appropriate connect_options.

rotate() changes the direction at which plotting starts by a clockwise rotation of # degrees from the default of opposite the vector mean. Such rotation is needed occasionally to avoid producing a loop that cuts itself.

twoway_options are options of twoway. By default the subtitle() indicates the mean direction and vector strength and is at pos(6). Note that the degree symbol can be specified by `=char(176)'.


. circvplot wallasp, title("Wall aspect", pos(12)) clcolor(blue) result(clcolor(red)) . graph display, xsize(4) ysize(4)


Nicholas J. Cox, University of Durham, U.K. n.j.cox@durham.ac.uk

Also see

On-line: help for circdplot (if installed), circrplot (if installed)