#  Copyright (C) 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008 Alan W. Irwin

#  Simple line plot and multiple windows demo.
#
#  This file is part of PLplot.
#
#  PLplot is free software; you can redistribute it and/or modify
#  it under the terms of the GNU Library General Public License as published
#  by the Free Software Foundation; either version 2 of the License, or
#  (at your option) any later version.
#
#  PLplot is distributed in the hope that it will be useful,
#  but WITHOUT ANY WARRANTY; without even the implied warranty of
#  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
#  GNU Library General Public License for more details.
#
#  You should have received a copy of the GNU Library General Public License
#  along with PLplot; if not, write to the Free Software
#  Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
#

from plplot_py_demos import *

# main
#
# Generates several simple line plots.  Demonstrates:
#   - subwindow capability
#   - setting up the window, drawing plot, and labelling
#   - changing the color
#   - automatic axis rescaling to exponential notation
#   - placing the axes in the middle of the box
#   - gridded coordinate axes

def main():

    # For starting from scratch this call to pladv increments cursub, but 
    # then the following plssub sets it to zero so the whole thing is 
    # essentially a nop.  However, for the case when other examples are run 
    # first, this call to pladv is absolutely essential to finish the 
    # preceding page.
    pladv(0)
    # Do plots on 4 subwindows of the first page
    plssub(2, 2)

    # Do a plot with one range of data

    plot1(6., 1., 0., 0.)
 
    # Do a plot with another range of data

    digmax = 5
    plsyax(digmax, 0)
    plot1(1., 0.0014, 0., 0.0185)
    
    plot2()
    
    plot3()

    # Restore defaults
#    plcol0(1)
    plssub(1, 1)
    pleop()

# ===============================================================

def plot1(xscale, yscale, xoff, yoff):

    x = xoff + (xscale/60.)*(1+arange(60))
    y = yoff + yscale*pow(x,2.)

    xmin = x[0]
    xmax = x[59]
    ymin = y[0]
    ymax = y[59]
    
    xs = x[3::10]
    ys = y[3::10]
    
    # Set up the viewport and window using pl.env. The range in X
    # is 0.0 to 6.0, and the range in Y is 0.0 to 30.0. The axes
    # are scaled separately (just = 0), and we just draw a
    # labelled box (axis = 0).
    
    plcol0(1)
    plenv(xmin, xmax, ymin, ymax, 0, 0)
    plcol0(2)
    pllab("(x)", "(y)", "#frPLplot Example 1 - y=x#u2")
    
    # Plot the data points
    
    plcol0(4)
    plpoin(xs, ys, 9)
    
    # Draw the line through the data
    
    plcol0(3)
    plline(x, y)
    
# ===============================================================

def plot2():

    # Set up the viewport and window using pl.env. The range in X
    # is -2.0 to 10.0, and the range in Y is -0.4 to 2.0. The axes
    # are scaled separately (just = 0), and we draw a box with
    # axes (axis = 1).
    
    plcol0(1)
    plenv(-2.0, 10.0, -0.4, 1.2, 0, 1)
    plcol0(2)
    pllab("(x)", "sin(x)/x", "#frPLplot Example 1 - Sinc Function")

    # Fill up the arrays

    x = (arange(100)-19)/6.0
    if 0.0 in x:
	#replace 0.0 by small value that gives the same sinc(x) result.
	x[list(x).index(0.0)] = 1.e-30
    y = sin(x)/x

    # Draw the line

    plcol0(3)
    plwidth(2)
    plline(x, y)
    plwidth(1)

# ===============================================================

def plot3():

    # For the final graph we wish to override the default tick
    # intervals, so do not use pl.env

    pladv(0)

    # Use standard viewport, and define X range from 0 to 360
    # degrees, Y range from -1.2 to 1.2.

    plvsta()
    plwind(0.0, 360.0, -1.2, 1.2)

    # Draw a box with ticks spaced 60 degrees apart in X, and 0.2 in Y.

    plcol0(1)
    plbox("bcnst", 60.0, 2, "bcnstv", 0.2, 2)

    # Superimpose a dashed line grid, with 1.5 mm marks and spaces. 
    # plstyl expects a pointer!! 

    plstyl([1500], [1500])
    plcol0(2)
    plbox("g", 30.0, 0, "g", 0.2, 0)
    plstyl([], [])

    plcol0(3)
    pllab("Angle (degrees)", "sine", "#frPLplot Example 1 - Sine function")

    x = 3.6*arange(101)
    y = sin((pi/180.)*x)

    plcol0(4)
    plline(x, y)

main()
