Add map tickmark examples (transit from NCL to PyNGL)

examples/colors_draw_colormap_from_file.py

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+#
+#  File:
+#    colors_draw_colormap_from_file.py
+#
+#  Synopsis:
+#    Demonstrates how to draw a color map (user defined) from file.
+#
+#  Category:
+#    colors
+#
+#  Based on NCL example:
+#    -
+#
+#  Author:
+#    Karin Meier-Fleischer
+#  
+#  Date of initial publication:
+#    November, 2018
+#
+#  Description:
+#    This example shows how to draw a color map (user defined) from file.
+#
+#  Effects illustrated:
+#    o  Drawing a color map
+#
+#  Output:
+#     A single visualization is produced.     
+#
+'''
+  PyNGL Example: 	colors_draw_colormap_from_file.py
+
+  -  Drawing a color map
+
+'''
+from __future__ import print_function
+import Ngl
+
+wks = Ngl.open_wks("x11","plot_user_defined_colormap")
+
+Ngl.draw_color_palette(wks,"./ccc-tool_colormap.rgb")
+
+Ngl.end()

examples/hov_1.py

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+#
+#  File:
+#    hov_1.py
+#
+#  Synopsis:
+#    Default black and white Hovmueller plot.
+#
+#  Category:
+#    contour plot
+#
+#  Based on NCL example:
+#    hov_1.ncl
+#
+#  Author:
+#    Karin Meier-Fleischer
+#  
+#  Date of initial publication:
+#    November, 2018
+#
+#  Description:
+#    This example shows how to create a default black and white Hovmueller plot.
+#
+#  Effects illustrated:
+#    o  Creating a Hovmueller plot
+#    o  Using text function codes to generate umlauts
+#
+#  Output:
+#     A single visualization is produced.     
+#
+'''
+  PyNGL Example: 	hov_1.py
+
+  -  Creating a Hovmueller plot
+  -  Using text function codes to generate umlauts
+
+'''
+from __future__ import print_function
+import numpy as np
+import os, sys
+import Ngl,Nio
+
+#-------------------------------------------------------
+#-- Function:	add_titles(wks,plot,resources,title,left,center,right)
+#-------------------------------------------------------
+def add_titles(wks,plot,title="",left="",center="",right=""):
+
+   vpx = Ngl.get_float(plot,"vpXF")             #-- retrieve value of res.vpXF from plot
+   vpy = Ngl.get_float(plot,"vpYF")             #-- retrieve value of res.vpYF from plot
+   vpw = Ngl.get_float(plot,"vpWidthF")         #-- retrieve value of res.vpWidthF from plot
+   vph = Ngl.get_float(plot,"vpHeightF")        #-- retrieve value of res.vpHeightF from plot
+
+   ymax = vpy+0.08                              #-- we need space for the title and strings
+
+   if(ymax > 0.98):
+     print("--> if you can't see the title use res.nglMaximize = False and/or set res.vpYF")
+
+#-- add title
+   if(title != ""):
+      tires = Ngl.Resources()
+      tires.txFontHeightF =  0.018
+      tires.txJust        = "CenterCenter"
+      tires.txFont        =  22                     #-- Font 22: Helvetica bold
+      if(left != "" or center != "" or right != ""):
+         y = vpy + 0.07
+      else:
+         y = vpy + 0.05
+      Ngl.text_ndc(wks, title, 0.5, y, tires)
+
+#-- add left, center and/or right string
+   txres = Ngl.Resources()
+   txres.txFontHeightF = 0.014                  #-- font size for left, center and right string
+
+   y = vpy + 0.035                              #-- y-position
+
+   if(left != ""):
+      txres.txJust = "CenterLeft"               #-- text justification
+      x = vpx                                   #-- x-position
+      Ngl.text_ndc(wks, left, x, y, txres)      #-- add text to wks
+
+   if(center != ""):
+      txres.txJust = "CenterCenter"             #-- text justification
+      Ngl.text_ndc(wks, center, 0.5, y, txres)  #-- add text to wks
+
+   if(right != ""):
+      txres.txJust = "CenterRight"              #-- text justification
+      x = vpx+vpw                               #-- x-position
+      Ngl.text_ndc(wks, right, x, y, txres)     #-- add text to wks
+
+#-------------------------------------------------------
+#--              MAIN
+#-------------------------------------------------------
+#-- data path and file name
+ncarg_root = os.environ.get('NCARG_ROOT')
+diri  = ncarg_root + '/lib/ncarg/data/cdf/'
+fname = 'chi200_ud_smooth.nc'
+
+#-- open file and read variables
+f     =  Nio.open_file(diri + fname,"r")    #-- open data file
+chi   =  f.variables['CHI'][:,:]            #-- read variable CHI[time,lon]
+lon   =  f.variables['lon'][:]
+time  =  f.variables['time'][:]
+
+scale =  1.0e6
+chi   =  chi/scale
+
+#-- create the plot
+wks =  Ngl.open_wks('png','plot_hovmueller')
+                                            #-- open workstation
+#-- set resources
+res                       =  Ngl.Resources
+res.nglFrame              =  False
+res.nglMaximize           =  False           #-- maximize plot output
+
+#res.tiMainString          = 'Default Hovmu~H-13V2F35~H~FV-2H3~ller' #-- title
+
+res.sfXArray              =  lon            #-- scalar field x
+res.sfYArray              =  time           #-- scalar field y
+
+res.tiYAxisString         = 'elapsed time'
+res.tmYLLabelFontHeightF  =  0.015
+
+res.nglPointTickmarksOutward = True         #-- point tickmarks out
+
+plot = Ngl.contour(wks,chi,res)             #-- draw contours 
+
+#-- delete resources because they will cause warnings (Why?)
+del([res.sfXArray,res.sfYArray,res.tiYAxisString,res.tmYLLabelFontHeightF])
+
+#-- add the title and left, center and/or right string
+title     = "Default Hovmu~H-13V2F35~H~FV-2H3~ller"
+long_name = f.variables["CHI"].attributes['long_name']
+units     = f.variables["CHI"].attributes['units']
+
+add_titles(wks,plot,title,left=long_name,right=units)
+
+#-- advance the frame
+Ngl.frame(wks)
+
+#-- end
+Ngl.end()

examples/hov_5.py

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+#
+#  File:
+#    hov_5.py
+#
+#  Synopsis:
+#    Default black and white Hovmueller plot.
+#
+#  Category:
+#    contour plot
+#
+#  Based on NCL example:
+#    hov_5.ncl
+#
+#  Author:
+#    Karin Meier-Fleischer
+#  
+#  Date of initial publication:
+#    November, 2018
+#
+#  Description:
+#    This example shows how to create a default black and white Hovmueller plot.
+#
+#  Effects illustrated:
+#    o  Creating a Hovmueller plot
+#    o  Using text function codes to generate umlauts
+#    o  Using contour fill
+#
+#  Output:
+#     A single visualization is produced.     
+#
+'''
+  PyNGL Example: 	hov_5.py
+
+  -  Creating a Hovmueller plot
+  -  Using text function codes to generate umlauts
+  -  Using contour fill
+
+'''
+from __future__ import print_function
+import numpy as np
+import os, sys
+import Ngl,Nio
+
+#-------------------------------------------------------
+#-- Function:	add_titles(wks,plot,resources,title,left,center,right)
+#-------------------------------------------------------
+def add_titles(wks,plot,title="",left="",center="",right=""):
+
+   vpx = Ngl.get_float(plot,"vpXF")             #-- retrieve value of res.vpXF from plot
+   vpy = Ngl.get_float(plot,"vpYF")             #-- retrieve value of res.vpYF from plot
+   vpw = Ngl.get_float(plot,"vpWidthF")         #-- retrieve value of res.vpWidthF from plot
+   vph = Ngl.get_float(plot,"vpHeightF")        #-- retrieve value of res.vpHeightF from plot
+
+   ymax = vpy+0.08                              #-- we need space for the title and strings
+
+   if(ymax > 0.98):
+     print("--> if you can't see the title use res.nglMaximize = False and/or set res.vpYF")
+
+#-- add title
+   if(title != ""):
+      tires = Ngl.Resources()
+      tires.txFontHeightF =  0.018
+      tires.txJust        = "CenterCenter"
+      tires.txFont        =  22                     #-- Font 22: Helvetica bold
+      if(left != "" or center != "" or right != ""):
+         y = vpy + 0.07
+      else:
+         y = vpy + 0.05
+      Ngl.text_ndc(wks, title, 0.5, y, tires)
+
+#-- add left, center and/or right string
+   txres = Ngl.Resources()
+   txres.txFontHeightF = 0.014                  #-- font size for left, center and right string
+
+   y = vpy + 0.035                              #-- y-position
+
+   if(left != ""):
+      txres.txJust = "CenterLeft"               #-- text justification
+      x = vpx                                   #-- x-position
+      Ngl.text_ndc(wks, left, x, y, txres)      #-- add text to wks
+
+   if(center != ""):
+      txres.txJust = "CenterCenter"             #-- text justification
+      Ngl.text_ndc(wks, center, 0.5, y, txres)  #-- add text to wks
+
+   if(right != ""):
+      txres.txJust = "CenterRight"              #-- text justification
+      x = vpx+vpw                               #-- x-position
+      Ngl.text_ndc(wks, right, x, y, txres)     #-- add text to wks
+
+#-------------------------------------------------------
+#--              MAIN
+#-------------------------------------------------------
+#-- data path and file name
+ncarg_root = os.environ.get('NCARG_ROOT')
+diri  = ncarg_root + '/lib/ncarg/data/cdf/'
+fname = 'chi200_ud_smooth.nc'
+
+#-- open file and read variables
+f     =  Nio.open_file(diri + fname,"r")    #-- open data file
+chi   =  f.variables['CHI'][:,:]            #-- read variable CHI[time,lon]
+lon   =  f.variables['lon'][:]
+time  =  f.variables['time'][:]
+
+scale =  1.0e6
+chi   =  chi/scale
+
+#-- create the plot
+wks =  Ngl.open_wks('png','plot_hovmueller_5')
+                                            #-- open workstation
+#-- set resources
+res                       =  Ngl.Resources
+res.nglFrame              =  False
+res.nglMaximize           =  False          #-- don't maximize plot output, yet
+
+res.cnFillOn              =  True           #-- turn on color fill
+res.cnFillPalette         = "BlWhRe"        #-- set color map
+res.cnLineLabelsOn        =  False
+res.cnLevelSelectionMode  = "ManualLevels"  #-- manual contour levels
+res.cnMinLevelValF        = -10.	        #-- min level
+res.cnMaxLevelValF        =  10.            #-- max level
+res.cnLevelSpacingF       =   2.            #-- contour level spacing
+
+res.lbOrientation         = "horizontal"    #-- horizontal labelbar
+
+res.sfXArray              =  lon[100:220]   #-- scalar field x
+res.sfYArray              =  time           #-- scalar field y
+
+res.tiYAxisString         = 'elapsed time'
+res.tmYLLabelFontHeightF  =  0.015
+
+res.nglPointTickmarksOutward = True         #-- point tickmarks out
+
+plot = Ngl.contour(wks,chi[:,100:220],res)             #-- draw contours 
+
+#-- delete resources because they will cause warnings (Why?)
+del([res.sfXArray,res.sfYArray,res.cnFillOn,res.cnFillPalette,res.cnLevelSelectionMode,\
+     res.cnLevelSpacingF,res.cnLineLabelsOn,res.cnMaxLevelValF,res.cnMinLevelValF,\
+     res.lbOrientation,res.tiYAxisString,res.tmYLLabelFontHeightF])
+
+#-- add the title and left, center and/or right string
+title     = "Default Hovmu~H-13V2F35~H~FV-2H3~ller"
+long_name = f.variables["CHI"].attributes['long_name']
+units     = f.variables["CHI"].attributes['units']
+
+add_titles(wks,plot,title,left=long_name,right=units)
+
+#-- advance the frame
+Ngl.frame(wks)
+
+#-- end
+Ngl.end()
+