<html><head><meta http-equiv="Content-Type" content="text/html charset=utf-8"></head><body style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space;" class="">Hi Francesco,<div class=""><br class=""></div><div class="">Before the line “<font face="Menlo" class="">wks = gsn_open_wks(typefile,namefile)</font>”, you can set the “<font face="Menlo" class="">wkBackgroundOpacityF</font>” attribute on the variable “<font face="Menlo" class="">typefile</font>” to 0.0 in order to make the workstation background fully transparent:</div><div class=""><font face="Menlo" class="">typefile@wkBackgroundOpacityF = 0.0</font></div><div class=""><font face="Menlo" class="">wks = gsn_open_wks(typefile,namefile)</font></div><div class=""><br class=""></div><div class="">Please note that this resource is only valid for certain workstation types (for example “png” is valid, but “pdf” and “ps” are not).</div><div class=""><br class=""></div><div class="">The <a href="https://www.ncl.ucar.edu/Document/Graphics/Resources/wk.shtml" class="">workstation resources documentation</a> on our website contains more information about “wkBackgroundOpacityF” and other potentially useful resources. </div><div class=""><br class=""></div><div class="">I hope this helps!</div><div class="">Kevin</div><div class=""><br class=""><div><blockquote type="cite" class=""><div class="">On Feb 26, 2018, at 5:29 PM, Francesco Trotta <<a href="mailto:francesco.trotta4@unibo.it" class="">francesco.trotta4@unibo.it</a>> wrote:</div><br class="Apple-interchange-newline"><div class=""><div style="margin-top: 0px; margin-bottom: 0px; font-family: Calibri, Arial, Helvetica, sans-serif; font-size: 16px; font-style: normal; font-variant-caps: normal; font-weight: normal; letter-spacing: normal; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px; -webkit-text-stroke-width: 0px; background-color: rgb(255, 255, 255);" class="">Dear ncl-support</div><div style="margin-top: 0px; margin-bottom: 0px; font-family: Calibri, Arial, Helvetica, sans-serif; font-size: 16px; font-style: normal; font-variant-caps: normal; font-weight: normal; letter-spacing: normal; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px; -webkit-text-stroke-width: 0px; background-color: rgb(255, 255, 255);" class=""> I'm generating a contour_map plot for the ocean temperature<span class="Apple-converted-space"> </span><br class=""></div><div style="margin-top: 0px; margin-bottom: 0px; font-family: Calibri, Arial, Helvetica, sans-serif; font-size: 16px; font-style: normal; font-variant-caps: normal; font-weight: normal; letter-spacing: normal; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px; -webkit-text-stroke-width: 0px; background-color: rgb(255, 255, 255);" class=""> I would like to generate a png with a background transparent beacause I want overlay the map on google map.<span class="Apple-converted-space"> </span><br class=""></div><div style="margin-top: 0px; margin-bottom: 0px; font-family: Calibri, Arial, Helvetica, sans-serif; font-size: 16px; font-style: normal; font-variant-caps: normal; font-weight: normal; letter-spacing: normal; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px; -webkit-text-stroke-width: 0px; background-color: rgb(255, 255, 255);" class=""> I'm using the following scripts but I got a white background</div><div style="margin-top: 0px; margin-bottom: 0px; font-family: Calibri, Arial, Helvetica, sans-serif; font-size: 16px; font-style: normal; font-variant-caps: normal; font-weight: normal; letter-spacing: normal; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px; -webkit-text-stroke-width: 0px; background-color: rgb(255, 255, 255);" class=""><br class=""></div><div style="margin-top: 0px; margin-bottom: 0px; font-family: Calibri, Arial, Helvetica, sans-serif; font-size: 16px; font-style: normal; font-variant-caps: normal; font-weight: normal; letter-spacing: normal; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px; -webkit-text-stroke-width: 0px; background-color: rgb(255, 255, 255);" class=""> How can I get a transparent background?<br class=""></div><div style="margin-top: 0px; margin-bottom: 0px; font-family: Calibri, Arial, Helvetica, sans-serif; font-size: 16px; font-style: normal; font-variant-caps: normal; font-weight: normal; letter-spacing: normal; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px; -webkit-text-stroke-width: 0px; background-color: rgb(255, 255, 255);" class="">thanks</div><div style="margin-top: 0px; margin-bottom: 0px; font-family: Calibri, Arial, Helvetica, sans-serif; font-size: 16px; font-style: normal; font-variant-caps: normal; font-weight: normal; letter-spacing: normal; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px; -webkit-text-stroke-width: 0px; background-color: rgb(255, 255, 255);" class="">Francesco<span class="Apple-converted-space"> </span><br class=""></div><div style="margin-top: 0px; margin-bottom: 0px; font-family: Calibri, Arial, Helvetica, sans-serif; font-size: 16px; font-style: normal; font-variant-caps: normal; font-weight: normal; letter-spacing: normal; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px; -webkit-text-stroke-width: 0px; background-color: rgb(255, 255, 255);" class=""><br class=""></div><div style="margin-top: 0px; margin-bottom: 0px; font-family: Calibri, Arial, Helvetica, sans-serif; font-size: 16px; font-style: normal; font-variant-caps: normal; font-weight: normal; letter-spacing: normal; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px; -webkit-text-stroke-width: 0px; background-color: rgb(255, 255, 255);" class=""><br class=""></div><div style="margin-top: 0px; margin-bottom: 0px; font-family: Calibri, Arial, Helvetica, sans-serif; font-size: 16px; font-style: normal; font-variant-caps: normal; font-weight: normal; letter-spacing: normal; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px; -webkit-text-stroke-width: 0px; background-color: rgb(255, 255, 255);" class=""> ;============== open a file ========================================<br class=""> wks = gsn_open_wks(typefile,namefile)<br class=""><br class=""> setvalues NhlGetWorkspaceObjectId()<br class=""> "wsMaximumSize" : 300000000<br class=""> end setvalues<br class=""><br class=""> ;============== miscellanous =======================================<br class=""> gsn_define_colormap(wks,colorsMap)<br class=""><br class=""> ;============== map resources ======================================<br class=""> res = True<br class=""> ;--- Title attributes -----------------------------------<br class=""> res@tiMainFont = 0<br class=""> res@tiMainPosition = "Center"<br class=""> res@tiMainFontHeightF = 0.011<br class=""> ;res@tiMainOffsetYF = 0.01<br class=""> ;--- GSN attributes -------------------------------------<br class=""> res@gsnDraw = False<br class=""> res@gsnFrame = False<br class=""> res@gsnMaximize = True<br class=""> res@gsnAddCyclic = False <br class=""> res@gsnSpreadColors = True<br class=""> ;--- Map attributes (window) ----------------------------<br class=""> res@mpLimitMode = "LatLon" ;Zoom in on the plot area<br class=""> res@mpMinLatF = minLatF<br class=""> res@mpMaxLatF = maxLatF<br class=""> res@mpMinLonF = minLonF<br class=""> res@mpMaxLonF = maxLonF<br class=""> ;--- Map attributes (projection) ----------------------------<br class=""> res@mpProjection = "mercator"<br class=""> ;--- Map attributes (land outlines) ---------------------<br class=""> res@mpDataBaseVersion = "HighRes" ;use GMT coastline<br class=""> res@mpOutlineOn = lmapOutlineOn ;turn on continental outlines<br class=""> res@mpOutlineBoundarySets = "AllBoundaries" ;turn on country boundaries (all the boundaries database in use)<br class=""> res@mpGeophysicalLineThicknessF = 2.5 ;thickness of outlines<br class=""> res@mpGeophysicalLineColor= "Black" ;color of cont. outlines<br class=""> res@mpOutlineDrawOrder = "PostDraw" ;draw continental outline last<br class=""> res@mpFillOn = False ;turn on gray fill for continental background<br class=""> res@pmTickMarkDisplayMode = "Always"<br class=""> ;--- Map attributes (lat/lon grid lines) ----------------<br class=""> res@mpGridAndLimbOn = False ;turn on lat/lon lines<br class=""> res@mpGridLineDashPattern = 2 ;... with xxxx lines<br class=""> res@mpGridLineColor = "black" ;color of the lines<br class=""> res@mpGridLatSpacingF = 10 ;space (in degree) between 2 lines<br class=""> res@mpGridLonSpacingF = 10 ;idem<br class=""> res@mpGridLineThicknessF = 2.0 ;thickness of the lines<br class=""> res@mpGridAndLimbDrawOrder= "PostDraw" ;draw lat/lon lines last<br class=""> res@mpLabelFontHeightF = 0.005 ;label font size<br class=""> ;--- contours attributes --------------------------------<br class=""> res@cnFillOn = True ;areas between levels filled with color<br class=""> res@cnFillMode = "AreaFill" ;AreaFill<br class=""> res@cnLevelSelectionMode = "ManualLevels" ;set manual contour levels<br class=""> res@cnMinLevelValF = minLevelVal ;set max contour level<br class=""> res@cnMaxLevelValF = maxLevelVal ;set min contour level<br class=""> res@cnLevelSpacingF = levelSpacing<br class=""> res@cnLinesOn = False ;turn off the contour lines<br class=""> res@cnLineLabelsOn = False ;turn off the line labels<br class=""> res@cnLineLabelFontHeightF= 0.005<br class=""> res@cnLineLabelDensityF = 1 ;label spacing when cnLineLabelPlacementMode != "Constant"<br class=""> res@cnLineLabelFontAspectF= 1 ;shape of the line label. > 1 :thinner characters. < 1 :wider<br class=""> res@cnLineLabelInterval = 1<br class=""> res@cnInfoLabelOn = False ;turn off "CONTOUR FROM X TO X BY X" legend.<br class=""> res@cnLabelMasking = True ;mask lines where label appear<br class=""> res@cnConstFEnableFill = True ;allow constant values (1=sig) to fill<br class=""> res@cnConstFLabelOn = False<br class=""> ;--- LabelBar attributes --------------------------------<br class=""> res@lbLabelBarOn = llabbarOn<br class=""> res@lbLabelsOn = llabbarLabelsOn<br class=""> ;res@lbTitleString = "("+field@units+")"<br class=""> res@lbOrientation = "vertical" ; vertical label bar<br class=""> ;res@pmLabelBarHeightF = 0.7<br class=""> res@lbTitlePosition = "Bottom"<br class=""> res@lbAutoManage = False ; Necessary to control sizes<br class=""> res@pmLabelBarWidthF = 0.1 ; default is shorter<br class=""> ;res@pmLabelBarHeightF = 0.1 ; default is taller<br class=""> ;res@lbLabelFontHeightF = .018 ; default is HUGE<br class=""> res@lbPerimOn = False ; default has box<br class=""> res@lbLeftMarginF = 0.0<span class="Apple-converted-space"> </span><br class=""> res@lbTopMarginF = 0.0 ; eliminate any margin at the top and left of the colorbar<br class=""> res@lbBottomMarginF = 0.0 ; eliminate any margin at the top and left of the colorbar<br class=""> res@lbLabelOffsetF = .05 ; this specifies the offset between the colorbar and the labels as a fraction of vpWidthF<span class="Apple-converted-space"> </span><br class=""> res@lbLabelAutoStride = True ; (optional) this ensures that labels do not overlap when the font height is made very large.<br class=""> res@lbLabelFontHeightF = 0.015<br class=""> res@lbTitleFontHeightF = 0.015<br class=""> ;res@lbLabelStride = 5 ; Label every 5th entry<br class=""> if (ismissing(minLevelVal) .or. ismissing(maxLevelVal)) then res@lbLabelStrings = ""<span class="Apple-converted-space"> </span><br class=""> else res@lbLabelStrings = "" + sprintf(labformatStr,fspan(minLevelVal,maxLevelVal, \<br class=""> floattoint((maxLevelVal-minLevelVal)/levelSpacing)+1)) end if<br class=""> <br class=""> ;-------------- scalars attributes ----------------------<br class=""> res@sfXArray = lon2d(0:ny-1,0:nx-1) ; abscisses<br class=""> res@sfYArray = lat2d(0:ny-1,0:nx-1) ; ordonnees<br class=""><br class=""> ;=== draw contour/contour lines ====================================<br class=""> plot = gsn_csm_contour_map(wks,field(:,:),res)<br class=""><br class=""> draw(plot)<br class=""> frame(wks)<br class=""><br class=""> system("convert -alpha off -background white -geometry "+typefile@wkWidth+"x"+typefile@wkHeight+ \<br class=""> " -density 300 -trim "+namefile+".png "+namefile+".png")<br class=""><br class=""></div><span style="font-family: Calibri, Arial, Helvetica, sans-serif; font-size: 16px; font-style: normal; font-variant-caps: normal; font-weight: normal; letter-spacing: normal; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px; -webkit-text-stroke-width: 0px; background-color: rgb(255, 255, 255); float: none; display: inline !important;" class="">_______________________________________________</span><br style="font-family: Calibri, Arial, Helvetica, sans-serif; font-size: 16px; font-style: normal; font-variant-caps: normal; font-weight: normal; letter-spacing: normal; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px; -webkit-text-stroke-width: 0px; background-color: rgb(255, 255, 255);" class=""><span style="font-family: Calibri, Arial, Helvetica, sans-serif; font-size: 16px; font-style: normal; font-variant-caps: normal; font-weight: normal; letter-spacing: normal; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px; -webkit-text-stroke-width: 0px; background-color: rgb(255, 255, 255); float: none; display: inline !important;" class="">ncl-talk mailing list</span><br style="font-family: Calibri, Arial, Helvetica, sans-serif; font-size: 16px; font-style: normal; font-variant-caps: normal; font-weight: normal; letter-spacing: normal; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px; -webkit-text-stroke-width: 0px; background-color: rgb(255, 255, 255);" class=""><a href="mailto:ncl-talk@ucar.edu" style="font-family: Calibri, Arial, Helvetica, sans-serif; font-size: 16px; font-style: normal; font-variant-caps: normal; font-weight: normal; letter-spacing: normal; orphans: auto; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: auto; word-spacing: 0px; -webkit-text-size-adjust: auto; -webkit-text-stroke-width: 0px; background-color: rgb(255, 255, 255);" class="">ncl-talk@ucar.edu</a><br style="font-family: Calibri, Arial, Helvetica, sans-serif; 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-webkit-text-stroke-width: 0px; background-color: rgb(255, 255, 255);" class=""><a href="http://mailman.ucar.edu/mailman/listinfo/ncl-talk" style="font-family: Calibri, Arial, Helvetica, sans-serif; font-size: 16px; font-style: normal; font-variant-caps: normal; font-weight: normal; letter-spacing: normal; orphans: auto; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: auto; word-spacing: 0px; -webkit-text-size-adjust: auto; -webkit-text-stroke-width: 0px; background-color: rgb(255, 255, 255);" class="">http://mailman.ucar.edu/mailman/listinfo/ncl-talk</a><br style="font-family: Calibri, Arial, Helvetica, sans-serif; font-size: 16px; font-style: normal; font-variant-caps: normal; font-weight: normal; letter-spacing: normal; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px; -webkit-text-stroke-width: 0px; background-color: rgb(255, 255, 255);" class=""></div></blockquote></div><br class=""></div></body></html>