Python vcs.getcolors函数代码示例

def initVCS(x,levs1,levs2,split):
    x.setcolormap("bl_to_darkred")
    iso1                = x.createisofill()
    #iso         = x.createboxfill()
    #iso.boxfill_type="custom"
    iso1.levels         = levs1
    iso1.ext_1          = True
    iso1.ext_2          = True
    cols                = vcs.getcolors(iso1.levels,split=split)
    iso1.fillareacolors = cols

    iso2                = x.createisofill()
    levs                = levs2
    iso2.levels         = levs
    iso2.ext_1          = True
    iso2.ext_2          = True
    cols                = vcs.getcolors(iso2.levels,split=1)
    iso2.fillareacolors = cols

    leg                 = x.createtextorientation()
    leg.halign          = "left"
    leg.height          = 8

    tmpl                = x.createtemplate()
    tmpl.blank()
    tmpl.scalefont(.9)

    oldOrientation = tmpl.legend.textorientation
    tmpl.legend.textorientation = leg
    for a in ["data","legend","box1","xlabel1","xtic1","ylabel1","ytic1"]:
        setattr(getattr(tmpl,a),"priority",1)

    Ez                  = EzTemplate.Multi(rows=3,columns=1,x=x,template=tmpl)
    Ez.legend.direction ='vertical'
    Ez.margins.left     =.05
    Ez.margins.right    =.05
    Ez.margins.top      =.05
    Ez.margins.bottom   =.05

    title               = x.createtext()
    title.height        = 14
    title.halign        = "center"
    title.x             = [.5]
    title.y             = [.975]

    t1                  = Ez.get(legend="local")
    t2                  = Ez.get(legend="local")
    t3                  = Ez.get(legend="local")

    del(Ez) ; # Purge EzTemplate object
    vcs.removeobject(vcs.elements['textorientation'][oldOrientation])

    return iso1,iso2,title,t1,t2,t3,tmpl

    def _updateContourLevelsAndColorsForCustomBoxfill(self):
        """Set contour information for a custom boxfill."""
        self._contourLevels = self._gm.levels

        if numpy.allclose(self._contourLevels[0], [0., 1.e20]) or \
              numpy.allclose(self._contourLevels, 1.e20):
            levs2 = vcs.mkscale(self._scalarRange[0],
                                self._scalarRange[1])
            if len(levs2) == 1: # constant value ?
                levs2 = [levs2[0], levs2[0] + .00001]
            self._contourLevels = []
            if self._gm.ext_1:
                ## user wants arrow at the end
                levs2[0] = -1.e20
            if self._gm.ext_2:
                ## user wants arrow at the end
                levs2[-1] = 1.e20
            for i in range(len(levs2) - 1):
                self._contourLevels.append([levs2[i], levs2[i+1]])
        else:
            if not isinstance(self._gm.levels[0], (list, tuple)):
                self._contourLevels = []
                levs2 = self._gm.levels
                if numpy.allclose(levs2[0], 1.e20):
                    levs2[0] = 0
                for i in range(len(levs2) - 1):
                    self._contourLevels.append([levs2[i], levs2[i+1]])

        # Contour colors:
        self._contourColors = self._gm.fillareacolors
        if self._contourColors is None:
            # TODO BUG levs2 may not be defined here...
            self._contourColors = vcs.getcolors(levs2, split=0)

 def vcs_colors(self):
     """Used internally, don't worry about it."""
     levs = self.levels
     if self._gm.fillareacolors:
         colors = self._gm.fillareacolors
         return colors
     else:
         real_levs = levs
         if self.ext_left:
             levs = levs[1:]
         if self.ext_right:
             levs = levs[:-1]
         colors = vcs.getcolors(levs, colors=range(self.color_1, self.color_2))
         levs = real_levs
         if len(colors) < len(levs):
             # Pad out colors to the right number of buckets
             diff = len(levs) - len(colors)
             colors += diff * colors[-1:]
         return sorted(colors)

    def _updateContourLevelsAndColorsGeneric(self):
        # Contour values:
        self._contourLevels = self._gm.levels
        if numpy.allclose(self._contourLevels[0], [0., 1.e20]) or \
                numpy.allclose(self._contourLevels, 1.e20):
            levs2 = vcs.mkscale(self._scalarRange[0],
                                self._scalarRange[1])
            if len(levs2) == 1:  # constant value ?
                levs2 = [levs2[0], levs2[0] + .00001]
            self._contourLevels = []
            if self._gm.ext_1:
                # user wants arrow at the end
                levs2[0] = -1.e20
            if self._gm.ext_2:
                # user wants arrow at the end
                levs2[-1] = 1.e20
            for i in range(len(levs2) - 1):
                self._contourLevels.append([levs2[i], levs2[i + 1]])
        else:
            if not isinstance(self._gm.levels[0], (list, tuple)):
                self._contourLevels = []
                levs2 = self._gm.levels
                if numpy.allclose(levs2[0], 1.e20):
                    levs2[0] = -1.e20
                for i in range(len(levs2) - 1):
                    self._contourLevels.append([levs2[i], levs2[i + 1]])
            else:
                levs2 = self._gm.levels

        if isinstance(self._contourLevels, numpy.ndarray):
            self._contourLevels = self._contourLevels.tolist()

        # Figure out colors
        self._contourColors = self._gm.fillareacolors
        if self._contourColors == [1] or self._contourColors is None:
            # TODO BUG It's possible that levs2 may not exist here...
            self._contourColors = vcs.getcolors(levs2, split=0)
            if isinstance(self._contourColors, (int, float)):
                self._contourColors = [self._contourColors]

def histogram(canvas, values, xaxis=None, yaxis=None):
    fa = canvas.createfillarea()
    t = canvas.gettemplate("default")
    fa.viewport = [t.data.x1, t.data.x2, t.data.y1, t.data.y2]
    num_fills = len(values)
    fa.color = vcs.getcolors(range(num_fills))
    x, y = [], []
    
    for i in range(num_fills):
        point1, point2 = i / float(num_fills), (i + 1) / float(num_fills)
        xl = [point1, point1, point2, point2]
        yl = [0, values[i], values[i], 0]
        x.append(xl)
        y.append(yl)
    fa.x = x
    fa.y = y

    outline = vcs.createline(source="default")
    outline.viewport = fa.viewport
    outline.x = x
    outline.y = y
    
    canvas.plot(fa)
    canvas.plot(outline)

#Filter the variable by lat and long
s = s(lat = (25., 75.6), lon = (25., 85.))

# Initialize a canvas
x = vcs.init()
# Set canvas resolution

# Set canvas colormap
x.setcolormap("bl_to_darkred")

# Set up some levels to filter data by
levs = [-1e20, -5, -4.5, -4, -3.5, -3, -2.5, -2, -1.5, -1, -.5, 0, .5, 1, 1.5, 2, 2.5, 3, 3.5, 4, 4.5, 5, 1e20]

# Retrieve the colors that would best spread the supplied range of colors
cols = vcs.getcolors(levs, range(239, 11, -1))

# Create and initilize an isofill
iso = x.createisofill()
iso.levels = levs

# Draw the extension arrows on either side of the color legend
iso.ext_1 = "y"
iso.ext_2 = "y"

# Set the fill colors to the ones we retrieved earlier
iso.fillareacolors = cols

# Create a label
txt = x.createtext()
txt.string = "Moscow"

import sys,cdms2,vcs
x=vcs.init()
f=cdms2.open(vcs.prefix+"/sample_data/clt.nc")
s=f("clt",time=slice(0,23))
#f=cdms2.open(sys.prefix+"/sample_data/sampleCurveGrid4.nc")
#f=cdms2.open(sys.prefix+"/sample_data/sampleGenGrid3.nc")
#s=f("sample")
gm = x.createisofill()
gm = x.createboxfill()
#gm=x.createisoline()
levs = vcs.mkevenlevels(20,80)
gm.levels= levs
gm.fillareacolors = vcs.getcolors(levs)
#gm = x.createmeshfill()
d = x.plot(s,gm)
#d = x.plot(s.filled())
raw_input("Press enter")
x.animate.create(thread_it=False,min=20,max=80)
x.animate.fps(5000)
x.animate.run()
raw_input("Press enter to end")
x.animate.stop()

def createTemplateandGM(x,min,max,deltaisof,deltaisol,days_line,ntemplate=1,orientation='landscape'):

##     x.scriptrun('resol_24.scr')
##     x.setcolormap('cmap')
    dot=x.createline()
    dot.type='dot'
    if orientation[0].lower()=='p':
        x.portrait()
    tmpl=x.createtemplate()

    ## Turns off everything
    for a in dir(tmpl):
        try:
            setattr(getattr(tmpl,a),'priority',0)
        except:
            pass

    ## Turns on what we want
    tmpl.data.priority=1
    tmpl.box1.priority=1
    tmpl.legend.priority=1
    tmpl.xlabel1.priority=1
    tmpl.xlabel2.priority=1
    tmpl.ylabel1.priority=2
    tmpl.ylabel2.priority=2
    tmpl.xtic1.priority=2
    tmpl.xtic2.priority=2
    tmpl.ytic1.priority=2
    tmpl.ytic2.priority=2
    tmpl.xname.priority=1
    tmpl.yname.priority=1
    tmpl.dataname.priority=1
    
    
    if ntemplate==2:
        tmpl.reset('x',.06,.44,tmpl.data.x1,tmpl.data.x2)
    else:
        tmpl.reset('x',.2,.9,tmpl.data.x1,tmpl.data.x2)
    tmpl.reset('y',.2,.9,tmpl.data.y1,tmpl.data.y2)
    tmpl.ytic2.x1=tmpl.data.x1
    tmpl.ytic2.x2=tmpl.data.x2
    tmpl.ytic2.line=dot

    to=x.createtextorientation()
    to.halign='center'
    tmpl.dataname.x=(tmpl.data.x1+tmpl.data.x2)/2.
    tmpl.dataname.y=tmpl.data.y2+.03
    tmpl.dataname.textorientation=to

    tmpl.legend.x1=.3
    tmpl.legend.x2=.7

    tmpl.yname.x=tmpl.yname.x-.01
    tmpl.xname.y=tmpl.xname.y-.075

    tmpl.xtic2.y1=tmpl.data.y1
    tmpl.xtic2.y2=tmpl.data.y2
    tmpl.xtic2.line=dot
    tmpl.scalefont(.8)
    
    
    tmplnoleg=x.createtemplate(source=tmpl.name)
    tmplnoleg.legend.priority=0
    isof=x.createisofill()
    levs2=list(numpy.arange(min,max,deltaisof))
    levs1a=list(numpy.arange(min,0,deltaisol))
    levs1b=list(numpy.arange(0,max,deltaisol))
    isof.levels=levs2
    isof.fillareacolors=vcs.getcolors(levs2,colors=range(16,40))

    levs1a=list(numpy.arange(min,0,deltaisol))
    levs1b=list(numpy.arange(0,max,deltaisol))

    isol1=x.createisoline()
    isol1.level=levs1a
    isol1.label='y'
    isol1.line=['dot']
    isol2=x.createisoline()
    isol2.level=levs1b
    isol2.label='y'

    tick2={}
    for i in days_line:
        tick2[1./i]=str(i)+' days'
    tick1={}
    for i in (0,):
        tick1[i]=' '

    for gm in [isof,isol1,isol2]:
        gm.datawc_x1=-15
        gm.datawc_x2=15
        gm.datawc_y1=0.
        gm.datawc_y2=.8
        gm.yticlabels2=tick2
        gm.xticlabels2=tick1
    return tmpl,tmplnoleg,isof,isol1,isol2

# Initialize canvas:
canvas = vcs.init()
canvas.setbgoutputdimensions(1200,1091,units="pixels")
canvas.drawlogooff()

# Create and plot quick boxfill with default settings:
boxfill=canvas.createboxfill()

# Change the type
boxfill.boxfill_type = 'custom'
levels = range(20,81,10)
boxfill.levels=levels
boxfill.ext_1="y"
boxfill.ext_2="y"
boxfill.fillareacolors=vcs.getcolors(boxfill.levels)

canvas.plot(clt, boxfill, bg=1)

# Load the image testing module:
testingDir = os.path.join(os.path.dirname(__file__), "..")
sys.path.append(testingDir)
import checkimage

# Create the test image and compare:
baseline = sys.argv[1]
testFile = "test_boxfill_custom_ext1_ext2.png"
canvas.png(testFile)
ret = checkimage.check_result_image(testFile, baseline,
                                    checkimage.defaultThreshold)
sys.exit(ret)

pr = f("precip_trend")

x = vcs.init()
vcs.scriptrun(ViridisScript)

colormapname = "bl_to_darkred"
# colormapname = "viridis"
x.setcolormap(colormapname)

iso = x.createisofill()

number_different_colors = 64
levels = numpy.arange(-1., 1.00001, 2. / float(number_different_colors + 1)).tolist()
iso.levels = levels

cols = vcs.getcolors(levels, split=0)

iso.fillareacolors = cols
iso.legend = vcs.mklabels(numpy.arange(-1, 1.01, .125))

# Now create a template to move things around a bit
t = x.createtemplate()
t.xmintic1.priority = 1  # turn on bottom sub ticks
t.xmintic2.priority = 1  # turn on top sub ticks
t.ymintic1.priority = 1  # turn on left sub ticks
t.ymintic2.priority = 1  # turn on right sub ticks

t.scale(.9, "x")
t.scale(1.8, "y")
t.moveto(.05, .1)
# Move legend

sys.path.append(pth)

f=cdms2.open(os.path.join(vcs.sample_data,"clt.nc"))
s=f("clt",slice(0,12)) # read only 12 times steps to speed up things

x=vcs.init()
x.setantialiasing(0)
x.drawlogooff()
x.setbgoutputdimensions(1200,1091,units="pixels")

iso=x.createisoline()
iso.label='y'
levs = range(0,101,10)
iso.level=levs
# add dummy values to levs to get the correct number of cols
cols=vcs.getcolors(levs+[56,])
print levs
print cols
iso.textcolors = cols
iso.linecolors = cols
x.plot(s,iso,bg=1)
x.animate.create()
print "Saving now"
prefix= os.path.split(__file__)[1][:-3]
x.animate.save("%s.mp4"%prefix)
pngs = x.animate.close(preserve_pngs = True) # so we can look at them again
src_pth = sys.argv[1]
pth = os.path.join(src_pth,prefix)
ret = 0
for p in pngs:
  print "Checking:",p

    def test_portrait(self):
        try:
            import vcs
        except:
            raise RuntimeError(
                "Sorry your python is not build with VCS support cannot geenrate portrait plots")

        import json
        # CDAT MODULES
        import pcmdi_metrics
        import pcmdi_metrics.graphics.portraits
        import MV2
        import numpy
        from genutil import statistics
        import os
        import sys
        import glob

        # CREATES VCS OBJECT AS A PORTAIT PLOT AND LOADS PLOT SETTINGS FOR
        # EXAMPLE
        x = vcs.init()
        x.portrait()
        # Turn off antialiasing for test suite
        x.setantialiasing(0)

        # PARAMETERS STUFF
        P = pcmdi_metrics.graphics.portraits.Portrait()

        # Turn off verbosity
        P.verbose = False

        P.PLOT_SETTINGS.levels = [-1.e20, -.5, -.4, -.3, -.2, -.1,
                                  0., .1, .2, .3, .4, .5, 1.e20]

        P.PLOT_SETTINGS.x1 = .1
        P.PLOT_SETTINGS.x2 = .85
        P.PLOT_SETTINGS.y1 = .12
        P.PLOT_SETTINGS.y2 = .95

        P.PLOT_SETTINGS.xtic2y1 = P.PLOT_SETTINGS.y1
        P.PLOT_SETTINGS.xtic2y2 = P.PLOT_SETTINGS.y2
        P.PLOT_SETTINGS.ytic2x1 = P.PLOT_SETTINGS.x1
        P.PLOT_SETTINGS.ytic2x2 = P.PLOT_SETTINGS.x2

        # P.PLOT_SETTINGS.missing_color = 3
        # P.PLOT_SETTINGS.logo = None
        P.PLOT_SETTINGS.time_stamp = None
        P.PLOT_SETTINGS.draw_mesh = 'n'
        # P.PLOT_SETTINGS.tictable.font = 3

        x.scriptrun(
            os.path.join(
                pcmdi_metrics.__path__[0],
                "..",
                "..",
                "..",
                "..",
                "share",
                "graphics",
                'vcs',
                'portraits.scr'))
        P.PLOT_SETTINGS.colormap = 'bl_rd_12'
        # cols=vcs.getcolors(P.PLOT_SETTINGS.levels,range(16,40),split=1)
        cols = vcs.getcolors(P.PLOT_SETTINGS.levels, range(144, 156), split=1)
        P.PLOT_SETTINGS.fillareacolors = cols

        P.PLOT_SETTINGS.parametertable.expansion = 100

        # LIST OF VARIABLES TO BE USED IN PORTRAIT PLOT
        vars = [
            'pr',
            'rsut',
            'rsutcs',
            'rlutcs',
            'tas',
            'tos',
            'sos',
            'zos',
            'ua-850',
            'ua-200',
            'zg-500']
        vars = []

        # LOAD METRICS DICTIONARIES FROM JSON FILES FOR EACH VAR AND STORE AS A
        # SINGLE DICTIONARY
        var_cmip5_dics = {}
        mods = set()
        json_files = glob.glob(
            os.path.join(
                pcmdi_metrics.__path__[0],
                "..",
                "..",
                "..",
                "..",
                "share",
                "CMIP_metrics_results",
                "CMIP5",
                "amip",
                "*.json"))

#.........这里部分代码省略.........

#.........这里部分代码省略.........
        # Do we use a predefined meshfill ?
        if meshfill is None:
            mtics={}
            for i in range(100):
                mtics[i-.5]=''
            icont = 1
            meshfill=x.createmeshfill()
            meshfill.xticlabels1=eval(data.getAxis(1).names)
            meshfill.yticlabels1=eval(data.getAxis(0).names)
            
            meshfill.datawc_x1=-.5
            meshfill.datawc_x2=data.shape[1]-.5
            meshfill.datawc_y1=-.5
            meshfill.datawc_y2=data.shape[0]-.5
            meshfill.mesh=self.PLOT_SETTINGS.draw_mesh
            meshfill.missing=self.PLOT_SETTINGS.missing_color
            meshfill.xticlabels2=mtics
            meshfill.yticlabels2=mtics
            if self.PLOT_SETTINGS.colormap is None:
                self.set_colormap(x)
            elif x.getcolormapname()!=self.PLOT_SETTINGS.colormap:
                x.setcolormap(self.PLOT_SETTINGS.colormap)
            
            if self.PLOT_SETTINGS.levels is None:
                min,max=vcs.minmax(data)
                if max!=0: max=max+.000001
                levs=vcs.mkscale(min,max)
            else:
                levs=self.PLOT_SETTINGS.levels

            if len(levs)>1:
                meshfill.levels=levs
                if self.PLOT_SETTINGS.fillareacolors is None:
                    cols=vcs.getcolors(levs,range(16,40),split=1)
                    meshfill.fillareacolors=cols
                else:
                    meshfill.fillareacolors=self.PLOT_SETTINGS.fillareacolors
            
##             self.setmeshfill(x,meshfill,levs)
##             if self.PLOT_SETTINGS.legend is None:
##                 meshfill.legend=vcs.mklabels(levs)
##             else:
##                 meshfill.legend=self.PLOT_SETTINGS.legend
            # Now creates the mesh associated
            n=int(multiple)
            ntot=int((multiple-n)*10+.1)
##             data=data
            sh=list(data.shape)
            sh.append(2)
            I=MV2.indices((sh[0],sh[1]))
            Y=I[0]
            X=I[1]
##             if ntot>1:
##                 meshfill.mesh='y'
            if ntot == 1:
                sh.append(4)
                M=MV2.zeros(sh)
                M[:,:,0,0]=Y-.5
                M[:,:,1,0]=X-.5
                M[:,:,0,1]=Y-.5
                M[:,:,1,1]=X+.5
                M[:,:,0,2]=Y+.5
                M[:,:,1,2]=X+.5
                M[:,:,0,3]=Y+.5
                M[:,:,1,3]=X-.5
                M=MV2.reshape(M,(sh[0]*sh[1],2,4))

import vcs, cdms2, os

vcs.download_sample_data_files()

# An example demonstrating patterns with meshfill
cltfile = cdms2.open(os.path.join(vcs.sample_data, "clt.nc"))
clt = cltfile("clt")

canvas = vcs.init()
iso = canvas.createisofill()

iso.fillareastyle = "hatch"
# Refer to http://uvcdat.llnl.gov/examples/pattern_chart.html for a list of patterns
iso.fillareaindices = [1, 2, 3, 4, 5]
iso.levels = [0, 20, 40, 60, 80, 100]
iso.fillareaopacity = [50.0, 85.1, 23.5, 99.9, 100]
iso.fillareacolors = vcs.getcolors(iso.levels)

canvas.plot(clt, iso)
canvas.png("isofill_pattern")

#.........这里部分代码省略.........
                        if varmin<0 and varmax>0 and hasattr(var,"RMSE"):
                            mx = max(-varmin,varmax)
                            #temporarily disabled from dicsussion with J. Potter on 4/28/16
                            #levels = [float(v) for v in vcs.mkscale( -mx,mx, nlevels, zero=-1 )]
                            levels = [float(v) for v in vcs.mkscale( varmin,varmax, nlevels, zero=-1 )]
                        else:
                            levels = [float(v) for v in vcs.mkscale( varmin, varmax, nlevels, zero=1 )]

                        # Exceptions occur because mkscale doesn't always work.  E.g. vcs.mkscale(0,1.e35,16)
                    except RuntimeWarning,err:
                        levels = []
                    if levels==[]:
                        ## Here's how to do it with percentiles (clip out large values first).
                        #pc05 = numpy.percentile(self.vars[0],0.05)
                        #pc95 = numpy.percentile(self.vars[0],0.95)
                        #levels = [float(v) for v in vcs.mkscale( pc05, pc95, nlevels-2 )]
                        #levels = [varmin]+levels+[varmax]
                        # Evenly distributed levels, after clipping out large values:
                        # This cannot be expected to work always, but it's better than doing nothing.
                        amed = numpy.median(self.vars[0]._data)
                        vclip = amed * 1.0e6
                        logger.warning("Graphics problems, clipping some data at %s",vclip)
                        self.vars[0]._data[ self.vars[0]._data > vclip ] = vclip
                        a = numpy.sort(self.vars[0]._data.flatten())
                        asp = numpy.array_split(a,nlevels)
                        afirsts = [c[0] for c in asp]+[asp[-1][-1]]
                        alasts = [asp[0][0]]+[c[-1] for c in asp]
                        levels = [0.5*(afirsts[i]+alasts[i]) for i in range(len(afirsts))]
                        levf = levels[0]
                        levl = levels[-1]
                        levels = [ round(lv,2) for lv in levels ]
                        levels[0] = round(1.1*levels[0]-0.1*levels[1],2)
                        levels[-1] = round(1.1*levels[-1]-0.1*levels[-2],2)

                # ... mkscale returns numpy.float64, which behaves unexpectedly in _setlevels when
                # passed a tuple value
                if levels is not None and len(levels)>0:
                    self.presentation.levels = levels
                    if varmin<0 and varmax>0 and hasattr(var,"model"):
                        self.presentation.fillareacolors=vcs.getcolors(levels,colors=range(16,240),split=1)
                #nlevels = max(1, len(levels) - 1)
                #self.presentation.list()
 
                #nlrange = range(nlevels+1)
                #nlrange.reverse()
                #self.presentation.legend = vcs.mklabels( self.presentation.levels )
                ## Once you set the levels, the VCS default color choice looks bad.  So you really
                ## have to set contour fill colors (integers from 0 through 255) too:
                #cmin = 32./nlevels
                #cmax = 255./nlevels
                ## A more flexible way to do what's going on here, thanks to Charles Doutriaux:
                ## r=10
                ## g=16
                ## b=20
                ## X.setcolorcell(16,r,g,b)
                ## colors = [16,17,18,...] etc.
                ## vcs.getcolors is useful, more complicated - see its doc string
                #colors =  [int(round(a*cmin+(nlevels-a)*cmax)) for a in nlrange]
                #self.presentation.fillareacolors = colors
                ##self.presentation.fillareacolors=[32,48,64,80,96,112,128,144,160,176,240]
            elif vcs.isvector(self.presentation) or self.presentation.__class__.__name__=="Gv":
                # axis min,max copied from isofill
                axaxi = {ax:id for id,ax in self.axax[seqgetattr(var,'id','')].items()}
                if 'X' in axaxi.keys() and 'Y' in axaxi.keys():
                    axx = axaxi['X']
                    axy = axaxi['Y']
                elif 'Y' in axaxi.keys() and 'Z' in axaxi.keys():
                    axx = axaxi['Y']
                    axy = axaxi['Z']
                self.presentation.datawc_x1 = axmin[axx]
                self.presentation.datawc_x2 = axmax[axx]
                self.presentation.datawc_y1 = axmin[axy]
                self.presentation.datawc_y2 = axmax[axy]

                vec = self.presentation

                #vec.scale = min(vcsx.bgX,vcsx.bgY)/10.
                # Former scale factor, didn't work on more than one variable.
                #   That is, 100 workrf for moisture transport, 10 for wind stress:
                vec.scale = min(vcsx.bgX,vcsx.bgY)/ 100.
                if hasattr(self.vars[0],'__getitem__') and not hasattr( self.vars[0], '__cdms_internals__'):
                    # generally a tuple of variables - we need 2 variables to describe a vector
                    v = self.vars[0][0]
                    w = self.vars[0][1]
                    vm = max(abs(v.min()),abs(v.max()))
                    wm = max(abs(w.min()),abs(w.max()))
                    vec.scale = 10 / math.sqrt( math.sqrt( vm**2 + wm**2 ))
                else:   # We shouldn't get here, but may as well try to make it work if possible:
                    logger.warning("Trying to make a vector plot without tuples!  Variables involved are:")
                    v = self.vars[0]
                    v = self.vars[1]
                nlats = latAxis(v).shape[0]
                nlons = lonAxis(w).shape[0]
                # vector density factor of 32 works for moisture transport, 16 for wind stress
                nlatvs = vcsx.bgY/32   # how many vectors we want in lat direction
                nlonvs = vcsx.bgX/32
                #self.strideX = int( 0.9* vcsx.bgX/nlons )
                #self.strideY = int( 0.6* vcsx.bgY/nlats )
                self.strideX = max(1, int( nlons/nlonvs )) # stride values must be at least 1
                self.strideY = max(1, int( nlats/nlatvs ))