Problem2_MoreFunctions.py

#!/usr/bin/env python
# Put in a function
# A) put all of this code into a function that takes a few arguments, namely the marker, markersize, lignstyle and color call this function plot_quasars
# B)  have all the arguments be default arguments set to the defaults that they are within plot currently.
# C) change the name of the figure depending on the combination of arguments given so that with each combination a new figure name is produced
# D) Try this out with many different combinations of arguments. Research the plot command to try to change the marker, markersize, linestyle, etc. appropriately



# Author: Jake VanderPlas
# License: BSD
#   The figure produced by this code is published in the textbook
#   "Statistics, Data Mining, and Machine Learning in Astronomy" (2013)
#   For more information, see http://astroML.github.com
#   To report a bug or issue, use the following forum:
#    https://groups.google.com/forum/#!forum/astroml-general
from matplotlib import pyplot as plt
from astroML.datasets import fetch_dr7_quasar

#----------------------------------------------------------------------
# This function adjusts matplotlib settings for a uniform feel in the textbook.
# Note that with usetex=True, fonts are rendered with LaTeX.  This may
# result in an error if LaTeX is not installed on your system.  In that case,
# you can set usetex to False.
from astroML.plotting import setup_text_plots

def plot_quasars(marker='.', markersize=2, linestyle='none', color='black'):

    setup_text_plots(fontsize=8, usetex=True)

    #------------------------------------------------------------
    # Fetch the quasar data
    data = fetch_dr7_quasar()

    # select the first 10000 points
    data = data[:10000]

    r = data['mag_r']
    i = data['mag_i']
    z = data['redshift']

    #------------------------------------------------------------
    # Plot the quasar data
    fig, ax = plt.subplots(figsize=(5, 3.75))
    ax.plot(z, r - i, marker=marker, markersize=markersize, linestyle=linestyle, color=color)

    ax.set_xlim(0, 5)
    ax.set_ylim(-0.5, 1.0)

    ax.set_xlabel(r'${\rm redshift}$')
    ax.set_ylabel(r'${\rm r-i}$')
    fig.savefig("problem2" + str(marker) + str(markersize) + str(linestyle) + str(color) + ".png")

plot_quasars()
plot_quasars(markersize=2, linestyle="solid", color="#0effff")
plot_quasars(marker="*", markersize=10, color="#0effff")