#
#  File:
#    TRANS_polyline_polygon_polymarker.py
#
#  Synopsis:
#    Illustrates how to use polylines, polygons and polymarker
#
#  Categories:
#    map plot
#    polylines
#    polygons
#    polymarker
#
#  Author:
#    Karin Meier-Fleischer, based on NCL example
#  
#  Date of initial publication:
#    September 2018
#
#  Description:
#    This example shows how to use polylines, polygons and polymarker.
#
#  Effects illustrated:
#    o  Drawing polylines
#    o  Drawing polygons
#    o  Drawing polymarker
# 
#  Output:
#    A single visualization is produced.
#
#  Notes: The data for this example can be downloaded from 
#    http://www.ncl.ucar.edu/Document/Manuals/NCL_User_Guide/Data/
#   
'''
  Transition Guide Python Example:   TRANS_polyline_polygon_polymarker.py

  -  Drawing a map
  -  Drawing polylines
  -  Drawing polygons
  -  Drawing all available (16) polymarkers
   
  2018-09-11  kmf
'''
import Ngl
import os

#-- open a workstation and define colormap

wks = Ngl.open_wks("png",os.path.basename(__file__).split('.')[0])

#-- set resources
res                    =  Ngl.Resources()  
res.nglDraw            =  False       #-- don't draw the plot yet
res.nglFrame           =  False       #-- don't advance the frame yet

res.mpFillOn           =  True
res.mpOutlineOn        =  False
res.mpOceanFillColor   = "Transparent"
res.mpLandFillColor    = "Gray80"
res.mpInlandWaterFillColor = "Gray80"
res.mpGridAndLimbOn    =  False       #-- don't draw grid lines

res.pmTickMarkDisplayMode   = "Always"          #-- turn on map tickmark

#-- create the map, but don't draw it yet
map = Ngl.map(wks,res)

#----------------------------------------------------------------
#-- polyline coordinates (Germany)
#----------------------------------------------------------------
x = [ 6.,  15.,  15.,   6.,   6.]
y = [47.5, 47.5, 54.5, 54.5, 47.5]
  
#-- polyline resources
plres                  =  Ngl.Resources()
plres.gsLineThicknessF =  2.0         #-- set line thickness
plres.gsLineColor      = "red"        #-- set line color

#-- add polyline to map
box_1 = Ngl.add_polyline(wks, map, x, y, plres)

#----------------------------------------------------------------
#-- polygon coordinates (Australia)
#----------------------------------------------------------------
x = [110., 160., 160., 110., 110.]
y = [-45., -45., -10., -10., -45.]
  
#-- polygon resources
pgres                  =  Ngl.Resources()
pgres.gsFillColor      = "green"      #-- fill color
pgres.gsFillOpacityF   =  0.3         #-- set opacity of polygon

#-- add filled polygon to map
gon_1 = Ngl.add_polygon(wks, map, x, y, pgres)

#----------------------------------------------------------------
#-- polygon coordinates (Greenland)
#----------------------------------------------------------------
x = [-75., -10., -10., -75., -75.]  #-- define polygon x-array
y = [ 55.,  55.,  87.,  87.,  57.]  #-- define polygon y-array

#-- polygon resources
pres                =  Ngl.Resources()
pres.gsFillColor    = "orange"        #-- fill color
pres.gsFillOpacityF =  0.2            #-- set opacity

#-- add polygon and polyline to map
gon_2 = Ngl.add_polygon(wks, map, x, y, pres)
plres.gsLineColor   = "darkorange"    #-- set line color
box_2 = Ngl.add_polyline(wks, map, x, y, plres)


#----------------------------------------------------------------
#-- polymarker resources
#----------------------------------------------------------------
pmres                  =  Ngl.Resources()
pmres.gsMarkerColor    = "blue"       #-- marker color
pmres.gsMarkerIndex    =  1           #-- use marker 1
pmres.gsMarkerSizeF    =  0.03        #-- set size of marker
pmres.gsLineThicknessF =  8.          #-- marker line thickness

#-- unique identifier name for polymarker drawing, here marker_1
marker_1 = Ngl.add_polymarker(wks, map, -100., 30., pmres)

#----------------------------------------------------------------
#-- draw all 16 marker on plot using unique identifier name and 
#-- additional map attribute settings
#----------------------------------------------------------------
x     = -160.                         #-- x-position of first marker
y     =  -80.                             #-- y-position of first marker
idstr = "poly"

for i in range(0,16):                 #-- 16 different marker
   pmres.gsMarkerIndex = i+1
   id = idstr + str(i)                #-- result is poly0-poly15
#-- add marker to map
   map.id = Ngl.add_polymarker(wks, map, x+(i*20.), y+(i*10.), pmres)

#----------------------------------------------------------------
#-- write strings at the bottom of the plot
#----------------------------------------------------------------
txres               =  Ngl.Resources()
txres.txFontHeightF =  0.014          #-- default size is HUGE!
txres.txFontColor   = "blue"
txres.txJust        = "CenterLeft"    #-- puts text on top of bars
dty = 0.23
Ngl.text_ndc(wks,"Marker", 0.1, dty, txres)

txres.txFontColor   = "red"
Ngl.text_ndc(wks,"Polyline", 0.2, dty, txres)

txres.txFontColor   = "green"
Ngl.text_ndc(wks,"Polygon transparent", 0.3, dty, txres)

txres.txFontColor   = "orange"
Ngl.text_ndc(wks,"Polyline/Polygon transparent", 0.5, dty, txres)

#-- create the plot and advance the frame
Ngl.draw(map)
Ngl.frame(wks)