PyNGL example panel plot#
Software requirements:
Python 2.7.x
Numpy 1.9.2
PyNGL/PyNIO 1.5.0
Run the panel example script:
python PyNGL_panel.py
Script PyNGL_panel.py:
'''
DKRZ PyNGL Script: PyNGL_panel.py
Description: plot 3 plots on one physical page
11.05.15 meier-fleischer(at)dkrz.de
'''
import numpy,sys,os
import Ngl, Nio
#-----------------------------------------------------------------------
#-- Function: main
#-----------------------------------------------------------------------
def main():
#-- define variables
diri = "$HOME/NCL/general/data/new_data/" #-- data directory
fname = "rectilinear_grid_2D.nc" #-- data file name
minval = 250. #-- minimum contour level
maxval = 315 #-- maximum contour level
inc = 5. #-- contour level spacing
ncn = (maxval-minval)/inc + 1 #-- number of contour levels
#-- open file and read variables
f = Nio.open_file(diri + fname,"r")
temp = f.variables["tsurf"][0,::-1,:] #-- first time step, reverse latitude
temp19 = f.variables["tsurf"][19,::-1,:] #-- first time step, reverse latitude
temp39 = f.variables["tsurf"][39,::-1,:] #-- first time step, reverse latitude
lat = f.variables["lat"][::-1] #-- reverse latitudes
lon = f.variables["lon"][:] #-- all longitudes
tempac = Ngl.add_cyclic(temp[:,:]) #-- add cyclic point
temp19ac = Ngl.add_cyclic(temp19[:,:]) #-- add cyclic point
temp39ac = Ngl.add_cyclic(temp39[:,:]) #-- add cyclic point
#-- open a workstation
wkres = Ngl.Resources() #-- generate an resources object for workstation
wkres.wkColorMap = "rainbow" #-- choose colormap
wkres.wkWidth = 1024 #-- width of workstation
wkres.wkHeight = 1024 #-- height of workstation
wks_type = "png" #-- output type
wks = Ngl.open_wks(wks_type,"Py_panel",wkres) #-- open workstation
#-- set res
res = Ngl.Resources() #-- generate an res object for plot
res.nglDraw = False #-- don't draw individual plots
res.nglFrame = False #-- don't advance frame
#-- viewport resources
res.vpXF = 0.1 #-- viewport x-position
res.vpYF = 0.75 #-- viewport y-position
res.vpWidthF = 0.7 #-- viewport width
res.vpHeightF = 0.7 #-- viewport height
#-- contour resources
res.cnFillOn = True #-- turn on contour fill
res.cnLineLabelsOn = False #-- turn off line labels
res.cnInfoLabelOn = False #-- turn off info label
res.cnLevelSelectionMode = "ManualLevels" #-- set manual levels
res.cnMinLevelValF = minval #-- minimum value
res.cnMaxLevelValF = maxval #-- maximum value
res.cnLevelSpacingF = inc #-- increment
#-- grid resources
res.sfXCStartV = float(min(lon)) #-- minimum longitude
res.sfXCEndV = float(max(lon)) #-- maximum longitude
res.sfYCStartV = float(min(lat)) #-- minimum latitude
res.sfYCEndV = float(max(lat)) #-- maximum latitude
#-- labelbar resources
res.pmLabelBarDisplayMode = "Never" #-- turn off the label bar
#-- assign plot array for all 3 plots
plot = []
#-- create the plots, but don't draw it yet
#-- plot 1
res.tiMainString = "time = 01" #-- title string
plot.append(Ngl.contour_map (wks,tempac,res)) #-- time = 0
#-- plot 2
res.tiMainString = "time = 20" #-- title string
plot.append(Ngl.contour_map (wks,temp19ac,res)) #-- time = 19
#-- plot 3
res.tiMainString = "time = 40" #-- title string
plot.append(Ngl.contour_map (wks,temp39ac,res)) #-- time = 39
#-- draw a common title string on top of the panel
textres = Ngl.Resources()
textres.txFontHeightF = 0.025 #-- title string size
Ngl.text_ndc(wks,"Panel Plot",0.5,.97,textres) #-- add title to plot
#-- set some panel resources: a common labelbar and title
#-- "[3,1]" indicates 3 row, 1 columns
panelres = Ngl.Resources()
panelres.nglPanelLabelBar = True #-- common labelbar
panelres.nglPanelYWhiteSpacePercent = 0 #-- reduce space between the panel plots
panelres.nglPanelXWhiteSpacePercent = 0 #-- reduce space between the panel plots
panelres.nglPanelTop = 0.95 #-- top position of panel
#-- create the panel
Ngl.panel(wks,plot,[3,1],panelres)
#-- done
Ngl.end()
if __name__ == '__main__':
main()
Result:
