#
#  File:
#    ngl10p.py
#
#  Synopsis:
#    Produces a publication XY plot.
#
#  Categories:
#    XY plot
#    Text
#
#  Author:
#    Fred Clare (based on a code of Mary Haley)
#  
#  Date of initial publication:
#    September, 2005
#
#  Description:
#    This example produces a single publication quality XY plot.
#
#  Effects illustrated:
#    o  XY plot markers and dashed lines.
#    o  Function codes in text strings.
# 
#  Output:
#    A single XY plot.
#
#  Notes:
#     

#
#  Import numpy.
#
from __future__ import print_function
import numpy

#
#  Import PyNGL support functions.
#
import Ngl

#
#  The function "wigley" performs computations on the input array
#  based on where the values are less than 1953, are between
#  1953 and 1973 inclusive, or greater than 1973.
#  
def wigley(time):
  y = numpy.zeros(time.shape).astype(type(time))
  numpy.putmask(y,numpy.less(time,1953.),         \
                ((time-1860.)/(1953.-1860.)) * 35.0)
  numpy.putmask(y,numpy.logical_and(numpy.greater_equal(time,1953.),  \
                                    numpy.less_equal(time,1973.)),    \
                ((time-1953.)/(1973.-1953.)) * (68. - 35.) + 35.)
  numpy.putmask(y,numpy.logical_and(numpy.greater(time,1973.),        \
                                    numpy.less_equal(time,1990.)),    \
                ((time-1973.)/(1990.-1973.)) * (75. - 68.) + 68.)
  return y

#
#  Main program.
#
time1 = numpy.array([1990,  1985,  1980,  1970,  1960,  1950,  1940,  1930, \
                     1920,  1910,  1900,  1890,  1880,  1870,  1860],
                     'i')
y1    = numpy.array([68.065, 65.00, 70.67, 63.06, 43.42, 28.28, 23.00,  \
                     20.250, 17.77, 15.36, 10.01,  6.40,  3.98,  2.18,  \
                      1.540], 'f')

time2 = numpy.arange(min(time1),max(time1)+1,1)

y2 = wigley(time2)      # Calculate proposed values as a function of time.

maxdim = max(y1.shape[0],y2.shape[0])
y    = -999.*numpy.ones((2,maxdim),'f')  # Create 2D arrays to
time = -999.*numpy.ones((2,maxdim),'f')  # hold 1D arrays above.

y[0,0:y1.shape[0]] = y1
y[1,0:y2.shape[0]] = y2

time[0,0:time1.shape[0]] = time1.astype('f')
time[1,0:time2.shape[0]] = time2.astype('f')

#
#  Open a workstation.
#
wks_type = "png"
wks = Ngl.open_wks(wks_type,"ngl10p")

resources = Ngl.Resources()

resources.caXMissingV = -999.
resources.caYMissingV = -999.

resources.vpWidthF     = 0.8
resources.vpXF         = 0.13

resources.tiMainString  = "~F22~Sulfur Emissions" # "~F22~" changes
resources.tiXAxisString = "~F22~Year"             # the font to "22"
resources.tiYAxisString = "~F22~Tg s/yr"          # which is helvetica
                                                    # bold.
resources.tmXBLabelFont = 21
resources.tmYLLabelFont = 21

resources.trXMinF              = 1855 # Set minimum X axes value.

resources.xyDashPatterns       = [16,0]   # ( dash, solid )
resources.xyMarkLineModes      = ["MarkLines","Lines"]
resources.xyMarker             = 1
resources.xyMarkerSizeF        = 0.05 # Default is 0.01

resources.nglFrame             = False # Don't advance the frame.

xy = Ngl.xy(wks,time,y,resources)  # Create and draw XY plot.

txresources               = Ngl.Resources()
txresources.txFontHeightF = 0.015
txresources.txJust        = "CenterLeft" # Default is "CenterCenter".
txresources.txFuncCode    = "~"          # Default is "~"

strings = ["Wigley (Moller/IPCC)",
       "~F22~CSM-proposed:~F~~C~(Orn et.al./GEIA + Smith)",
       "~F22~CSM SO~B~4~N~ Scaling Factor: ~V1Q~~F22~S~B~emis~N~ (yr)~H-7Q~~V-1Q~---------------~H-9Q~~V-1Q~S~B~emis~N~ (1985)"]

xpos = [1885.,1940.,1860.]   # Define X/Y locations for text.
ypos = [30.,18.,70.]

#
#  Loop through text strings and plot them.
#
for i in range(0,len(strings)):
  Ngl.text(wks,xy,strings[i],xpos[i],ypos[i],txresources)

Ngl.frame(wks)

Ngl.end()