A little script for plotting things using YAML front matter for cofiguration

ploty.bat

#@echo off & python -x %~f0 %* & goto :eof 
##!/bin/python

# Meant to be used as executable, i.e. place this file somewhere in your path
# and uncomment the first line as necessary.
#
# Data file are expected to be formatted as:
#
# x_0,y1_0,y2_0,...,yN_0
# ...
# x_m,y1_m,y2_m,...,yN_m
#
# Any option can be overridden with YAML front matter. See the example file
# below.
#
# Note, including an `iamge_format` will cause your figure to be saved to disk
# rather than shown.

import matplotlib.pyplot as plt
import os
import sys
import yaml

args = sys.argv[1:]
cwd = os.getcwd()

if len(args) is not 1:
  print('Expected a single parameter, a data file to plot.')
  sys.exit(0)

# Can all be overidden with YAML front matter
opts = {
  'title': 'My Chart',
  'legend_loc': 'best',
  'x_label': 'Domain',
  'y_label': 'Range',
  'show_grid': True,
  'sep': ',',
  'x_lim': False,
  'y_lim': False,
  'image_format': False,
  'series_labels': [
    'Blue Stars',
    'Green Circles',
    'Red Triagles',
    'Cyan Diamonds'
  ],

  'plot_fn': 'plot',

  # Line chart stuff - plot_fn: plot
  'series_formats': ['b-*', 'g-o', 'r-^', 'c-D'],

  # Bar chart stuff - plot_fn: bar
  'colors': ['blue', 'green', 'red', 'cyan']
}

data_file_path = os.path.join(cwd, args[0])

with open(data_file_path) as data_file:
  # Check for yaml front matter
  lines = data_file.readlines()
  ix = 0

  # Merge defaults opts with YAML front matter
  if lines[ix].strip() == '---':
    yaml_lines = [lines[ix]]
    ix = 1
    while lines[ix].strip() != '---':
      yaml_lines.append(lines[ix])
      ix = ix + 1
    ix = ix + 1
    opts = { **opts, **yaml.load('\n'.join(yaml_lines)) }

  # Process data opts
  data_lines = lines[ix:]
  data_rows = [line.split(opts['sep']) for line in data_lines]
  num_series = len(data_rows[0]) - 1
  data_rows = [row for row in data_rows if len(row) == num_series + 1]

  plt.figure()

  if opts['title']:
    plt.title(opts['title'])

  if opts['x_label']:
    plt.xlabel(opts['x_label'])

  if opts['y_label']:
    plt.ylabel(opts['y_label'])

  if opts['x_lim']:
    plt.xlim(opts['x_lim'][0], opts['x_lim'][1])

  if opts['y_lim']:
    plt.ylim(opts['y_lim'][0], opts['y_lim'][1])

  if opts['show_grid']:
    plt.grid()

  x_domain = [row[0] for row in data_rows]

  for ix_series in range(1, num_series + 1):
    y_range = [row[ix_series].strip() for row in data_rows]

    if opts['plot_fn'] == 'bar':
      ind = [x for x in range(len(x_domain))]
      for ix in ind:
        y_val = y_range[ix]
        y_val = float(y_val) if '.' in y_val else int(y_val)
        plt.bar(ind[ix], y_val, label=y_val, color=opts['colors'][ix])
      plt.xticks(ind, x_domain)
    else:
      # Default plot_fn is `plot`
      y_format = opts['series_formats'][ix_series - 1]
      series_label = opts['series_labels'][ix_series - 1]
      plt.plot(x_domain, y_range, y_format, label=series_label)

  if opts['legend_loc']:
    plt.legend(loc=opts['legend_loc'])

  if opts['image_format']:
    image_file_name, _ = os.path.splitext(os.path.basename(data_file_path))
    image_file_path = os.path.join(cwd, image_file_name + '.' + opts['image_format'])
    plt.savefig(image_file_path)
  else:
    plt.show()

# vi:syntax=python

silly-example-data-file.txt

---
title: Test
x_label: Foobar
series_labels:
  - Thing 1
  - Thing 2
---
1,3,4
2,4,1
3,2,7