coloring vectors using a scalar

I'm trying to color vectors using a scalar with the gsn_csm_vector_scalar_map function. My understanding is that this should be the default behavior, but the vectors are still colored by magnitude. I've included a code snippet below. Commented code are options that I have tried in various combinations. Thanks.

; Open a workspace to begin creating the plot
wsplot = gsn_open_wks("ps", "./graphs/anomavgNARR."+filemidout+"."+i)

; Change options for plot (res=True)
res = True

; Color fill on, contours off, line labels off, manual level selection
; mode, spacing every 1.0 units, min value 270, max value 320, use
; entire color spectrum
res@gsnSpreadColors = True

; set vector resources
res@vfXCStride = 4
res@vfYCStride = 4
res@vcRefMagnitudeF = 100000.0
res@vcRefLengthF = 0.008
res@vcGlyphStyle = "LineArrow"
res@vcRefAnnoOrthogonalPosF = -1.0
res@vcRefAnnoParallelPosF = 1.0
res@vcLineArrowThicknessF = 3.0
res@vcVectorDrawOrder = "PostDraw"
res@vcMapDirection = False

;res@sfDataArray = vectorcolor
;res@vcLevelSelectionMode = "ExplicitLevels"
res@vcScalarFieldData = vectorcolor
;res@vcVectorFieldData =
res@vcMonoLineArrowColor = False
;res@sfMissingValueV = -999
res@vcScalarMissingValColor = -1
res@vcUseScalarArray = True
;res@vcLevelColors = (/0,1,2,3/)
;res@vcLevels = (/-0.5,0,0.5/)
;res@vcLevelCount = 3

; Draw map boundaries: coastlines, national boundaries, and states/provinces
res@mpAreaMaskingOn = False
res@mpFillOn = False
res@mpDataBaseVersion="Ncarg4_1"
res@mpOutlineBoundarySets = "National"
res@mpOutlineSpecifiers = (/"Canada:Provinces", "United States:States", "Mexico:States"/)

; Always display tick marks
res@pmTickMarkDisplayMode = "Always"
; Do not add cyclic reference point, maximize plot to workstation size,
; orient paper horizontally, 0.5 inch paper margin
res@gsnAddCyclic = False
res@gsnMaximize = True
res@gsnPaperOrientation = "landscape"
res@gsnPaperMargin = 0.5
; blank strings above image
res@gsnCenterString = ""
res@gsnRightString = ""
res@gsnLeftString = ""
res@gsnScalarContour = False

; Define map projection properties
res@mpProjection = "LambertConformal"
res@mpLambertMeridianF = 253
res@mpLambertParallel1F = 50
res@mpLambertParallel2F = 50

; Define display boundaries
res@mpLimitMode = "Corners"
res@mpLeftCornerLatF = lat2d(0,nlat/6)
res@mpLeftCornerLonF = lon2d(0,nlat/6)
res@mpRightCornerLatF = lat2d(mlon/2,nlat-nlat/3)
res@mpRightCornerLonF = lon2d(mlon/2,nlat-nlat/3)
; map perimeter on, map fill on, no map rotation
res@mpPerimOn = True
res@mpCenterRotF = 0
; 10deg lat-lon grid spacing, show lat-lon grid, make lat-lon lines
; dashed
res@mpGridSpacingF = 10.0
res@mpGridAndLimbOn = True
res@mpGridLineDashPattern = 16
; NCDOverlay is false
res@tfDoNDCOverlay = False

; Create the label bar for the colored contours
res@lbLabelFontHeightF = 0.020
res@lbTitleString = ""
res@lbLabelFont = 21
res@lbLabelAutoStride = False
res@lbLabelStride = 10
res@lbOrientation = "Vertical"
res@pmLabelBarOrthogonalPosF = 0.02
res@pmLabelZone = 2
res@lbBoxLinesOn = True

; Define the colorscale for the plot and reverse it (R-W-B)
gsn_define_colormap(wsplot, "cosam")

; Create the plot
plot = gsn_csm_vector_scalar_map(wsplot, plotthisu(:,:), plotthisv(:,:), vectorcolor(:,:), res)

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
* Nicole Schiffer
* Graduate Research Assistant
* Department of Atmospheric Sciences
* University of Illinois, Urbana-Champaign
* Email: nschiff2 [at] illinois [dot] edu
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

_______________________________________________
ncl-talk mailing list
List instructions, subscriber options, unsubscribe:
http://mailman.ucar.edu/mailman/listinfo/ncl-talk
Received on Fri Nov 13 19:32:37 2009