import math

#The following is a course module that
#gets you graphics and basic data handling
#and numerical analysis routines
from ClimateUtilities import *


#Define the function you are going to plot.
#It has a parameter, "a"

def f(x,a):
    return math.exp(-x*x/(a*a))

#Make a list of the values of x you want to use
xList = [-2. + .1*i for i in range(21)]

#Make a list of the values of the function for two different
#parameter values
f1List = [f(x,1.) for x in xList]
f2List = [f(x,2.) for x in xList]

#Put the values in a Curve() object, for output and plotting
#the Curve class is defined in ClimateUtilities
c = Curve()
c.addCurve(xList,'x','x axis') #Third argument is a label. It's optional
c.addCurve(f1List,'f1','f(x,1)')
c.addCurve(f2List,'f2','f(x,2)')

#Dump the results out to a text file, so you can
#plot it using your favorite plotting software if you like
c.dump('fData.txt') #Argument is the file name

#Now plot to the screen. The plot function returns a
#"plot object", which we call "w" here. This allows the
#plot to be saved later
w = plot(c)

#Now let's add a plot title and some axis labels and plot again.
#Plot specifications are stored in the curve object


#Now plot it again and see how we like it
c.PlotTitle = 'The Gaussian' #Title of the plot
c.Xlabel = 'The X axis' #X axis label
c.Ylabel = 'Function Value' #Y axis label
w1 = plot(c)

#Now make the vertical axis logarithmic
c.YlogAxis = True
w2 = plot(c)

#Save the plot as an EPS file, for use in a paper or report
#Most good graphics programs can open an eps file, as well as
#most word processors.  Even the basic Preview software on the Mac
#can open an eps and let you copy and paste it into another document
#
#Note that the plot (like the data in the c.dump(...) example) will
#be saved on the computer that is running Python.  If you are running
#python remotely, via a terminal connection or x11, you will need to
#move the file 
w2.save('myplot') #File will be saved as 'myplot.eps'

#----------------Advanced Topic---------------------------------
#       How to save the entire Curve object for future use
#
#In the c.dump(...) example above, only the data in the curve
#object is written to a file. This is done deliberately, so that
#the data will wind up in a plain-vanilla text file that can
#be read and used by just about any software.  However, this
#file doesn't preserve the other things stored in the Curve object,
#like plot titles and axis options.  Python provides a means of preserving
#an entire object for future use, known as "pickling."  This process
#is illustrated in the following example.
#
#First import the pickle module
import pickle
#
#Now open a file for output. The open statement returns a file object
outfile = open('testpickle.out','w') #The "w" means create new file for write
#
#Pickle the curve object and put it in the file
pickle.dump(c,outfile)
#
#Close the file
outfile.close()

#Now let's open the file for input, read in the curve, and plot it
infile = open('testpickle.out')
newC = pickle.load(infile)
plot(newC)