[dev-scripts] Add a new tool called scurve_printer to print scurve data produced by csvcolumn_to_scurve.

This used matplotlib internally to plot the values. Now one can produce scurves
without leaving the command line.

I tried to get logarithmic scale to work, but I was unable to do so in a trivial
way. That is something for a different hacking session. I need to move on.

Author: gottesmm

utils/dev-scripts/scurve_printer.py

@@ -0,0 +1,88 @@
+#!/usr/bin/env python
+
+# This is a simple script that takes in an scurve file produced by
+# csvcolumn_to_scurve and produces a png graph of the scurve.
+
+import argparse
+import csv
+
+import matplotlib.pyplot as plt
+
+import numpy as np
+
+FIELDS = ['N/total', 'New/Old']
+
+
+def get_data(input_file):
+    global FIELDS
+    for row in csv.DictReader(input_file):
+        yield (float(row[FIELDS[0]]), float(row[FIELDS[1]]))
+
+
+def main():
+    p = argparse.ArgumentParser()
+    p.add_argument('input_csv_file', type=argparse.FileType('r'))
+    p.add_argument('output_file', type=str)
+    p.add_argument('-y-axis-num-tick-marks', type=int,
+                   help='The number of y tick marks to use above/below zero.')
+    p.add_argument('-y-axis-min', type=float,
+                   help='Override the min y axis that we use')
+    p.add_argument('-y-axis-max', type=float,
+                   help='Override the min y axis that we use')
+    p.add_argument('-title', type=str,
+                   help='Title of the graph')
+    p.add_argument('-x-axis-title', type=str,
+                   help='The title to use on the x-axis of the graph')
+    p.add_argument('-y-axis-title', type=str,
+                   help='The title to use on the x-axis of the graph')
+
+    args = p.parse_args()
+
+    data = np.array(list(get_data(args.input_csv_file)))
+    assert np.all(data >= 0)
+
+    x = data[:, 0]
+    y = data[:, 1]
+
+    x_axis_title = args.x_axis_title or FIELDS[0]
+    y_axis_title = args.y_axis_title or FIELDS[1]
+    title = args.title or "{} vs {}".format(x_axis_title, y_axis_title)
+
+    fig, ax = plt.subplots()
+    fig.set_size_inches(18.5, 18.5)
+
+    fig.suptitle(title, fontsize=20)
+    ax.set_xlabel(x_axis_title, fontsize=20)
+    ax.set_ylabel(y_axis_title, fontsize=20)
+    ax.plot(x, y)
+    ax.scatter(x, y)
+
+    # To get good bounds, we:
+    #
+    # 1. Re-center our data at 0 by subtracting 1. This will give us the %
+    # difference in between new and old (i.e. (new - old)/old)
+    #
+    # 2. Then we take the maximum absolute delta from zero and round to a
+    # multiple of 5 away from zero. Lets call this value limit.
+    #
+    # 3. We set [min_y, max_y] = [1.0 - limit, 1.0 + limit]
+    recentered_data = y - 1.0
+    max_magnitude = int(np.max(np.abs(recentered_data)) * 100.0)
+    y_limit = float(((max_magnitude // 5) + 1) * 5) * 0.01
+
+    ax.set_xlim(0.0, 1.0)
+    y_min = args.y_axis_min or 1.0 - y_limit
+    y_max = args.y_axis_max or 1.0 + y_limit
+    assert(y_min <= y_max)
+    ax.set_ylim(y_min, y_max)
+    ax.grid(True)
+    ax.xaxis.set_ticks(np.arange(0.0, 1.0, 0.05))
+    if args.y_axis_num_tick_marks:
+        y_delta = y_max - y_min
+        y_tickmark_frequency = y_delta / float(args.y_axis_num_tick_marks)
+        ax.yaxis.set_ticks(np.arange(y_min, y_max, y_tickmark_frequency))
+    plt.savefig(args.output_file)
+
+
+if __name__ == "__main__":
+    main()