begin f = addfile("pop.nc","r") ; POP model data. u = f->urot v = f->vrot u@lat2d = f->lat2d u@lon2d = f->lon2d v@lat2d = f->lat2d v@lon2d = f->lon2d wks = gsn_open_wks("png","vector1f") ; Open png file called "vector1f.png" res = True ; Plot options set res@gsnAddCyclic = True ; Add a longitude cyclic point. res@vcMonoLineArrowColor = False ; Turn on color vectors res@vcLevelPalette = "gui_default" ; Change color map. res@vcRefMagnitudeF = 40 ; Define reference magnitude res@vcRefLengthF = 0.045 ; Define length of vector reference res@vcRefAnnoOrthogonalPosF = -0.13 ; Move reference into plot. res@vcRefAnnoArrowUseVecColor = False ; Allow us to change ref vec color res@vcRefAnnoArrowLineColor = "black" ; Black ref vector ; ; Instead of thinning the vectors by subscripting the data with "::4", ; you can instead thin the vectors with the resource below. ; res@vcMinDistanceF = 0.005 ; Thin the vectors res@mpFillDrawOrder = "Postdraw" ; Draw filled map last plot = gsn_csm_vector_map(wks,u,v,res) ; Call the gsn_csm function for ; drawing the vectors over a map. end