Cook et al. 2017 - Matplotlib moficatoions

This is a work in progress - program dump.

All code should be taken as work in progress.

Comments/Problems email neil.james.cook@gmail.com

Related Formatter

Taken and edited from http://www.baryons.org/RelatedTicker/

Additions: TimeFormatter function

class TimeFormatter(Formatter):

takes transformation function and time format string and converts axis to time formatted axis

the transformation function must return the time in decimal hours

Formats currently allowed:

"H"       format is 16h
"H.H"     format is 16.1h
"H.HH"    format is 16.12
"HM"      format is 16h 7m
"HM.M"    format is 16h 7.4m
"HM.MM"   format is 16h 7.41m
"HMS"     format is 16h 7m 24s
"HMS.S"   format is 16h 7m 24.4s
"HMS.SS"  format is 16h 7m 24.44s

Example use

import matplotlib.pyplot as plt
from RelatedFormatter import TimeFormatter as TimeFormatter
from RelatedLocator import RelatedLocator as Locator

def deg_to_hours(x):
  """
  Converts degress in to hours for right ascension
  x [deg] = x*24.0/360.0 = x/15.0
  :param x: right ascension position in degrees
  :return x/15.0: right ascnesion position in hours
  """
  return x/15.0

fig, ax = plt.subplots(ncols=1, nrows=1)
ax.scatter([0, 90, 180, 270, 360], [-10, -12, -10, -12, -10])
xax = ax.xaxis
xax.set_major_locator(Locator(deg_to_hours, 0.25))
xax.set_major_formatter(TimeFormatter(deg_to_hours, "HMS"))
ax.set(xlabel="Right Ascension", ylabel="Declination")
plt.show()
plt.close()

Related Locator

Taken from http://www.baryons.org/RelatedTicker/ (Unedited but here for ease of use)

Right Asencion Axis

function ra_axis(frame, axis_format='HMS.SS')

Converts the right ascension axis from degrees into hours/hours minutes/ hours/minutes/seconds

• :param frame: matplotlib axis (ax), i.e. plt.subplot(111) or plt.gca()

• :param axis_format: string, format of the ra_axis currently supported are:

  For ra = 241.85184 degrees

    "H"       format is 16h
    "H.H"     format is 16.1h
    "H.HH"    format is 16.12
    "HM"      format is 16h 7m
    "HM.M"    format is 16h 7.4m
    "HM.MM"   format is 16h 7.41m
    "HMS"     format is 16h 7m 24s
    "HMS.S"   format is 16h 7m 24.4s
    "HMS.SS"  format is 16h 7m 24.44s
  

  default is "HMS.SS"

  Example of use

import numpy as np
import matplotlib.pyplot as plt
from matplotlib_mod import right_ascension_axis as ra_axis

# make fake data
ra = np.random.randint(2300000, 2500000, 1000)
dec = np.random.randint(250000, 350000, 1000)
ra = np.array(ra, dtype=float)/10000
dec = np.array(dec, dtype=float)/10000

# plot data
plt.close()
fig, frame = plt.subplots(ncols=1, nrows=1)
frame.scatter(ra, dec)

# change x-axis
frame = ra_axis(frame)

# set labels
frame.set_xlabel('Right Ascension')
frame.set_ylabel('Declination')

# show and close
plt.show()
plt.close()

Rainbow text

Extended version of http://matplotlib.org/examples/text_labels_and_annotations/rainbow_text.html

function rtext(x, y, strings, colors, ax=None, orientation='horizontal', **kw)

Take a list of strings and colors and place them next to each other, with text strings[i] being shown in colors[i].

This example shows how to do both vertical and horizontal text, and will pass all keyword arguments to plt.text, so you can set the font size, family, etc.

The text will get added to the ax axes, if provided, otherwise the currently active axes will be used.

from: http://matplotlib.org/examples/text_labels_and_annotations/rainbow_text.html

• :param x: float, location on the plot (see plt.text)
• :param y: float, location on the plot (see plt.text)
• :param strings: list of strings, containing the words to color
• :param colors: list of strings, containing the colour of each word
• :param ax: plt.gca() axis or frame
• :param orientation: string, "h"/"horizontal" or "v"/"vertical"
• :param kw: dictionary, keyword arguments to be passed to plt.text