libc/AOR_v20.02/math/tools/plot.py

   1 #!/usr/bin/env python
   2
   3 # ULP error plot tool.
   4 #
   5 # Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
   6 # See https://llvm.org/LICENSE.txt for license information.
   7 # SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
   8
   9 import numpy as np
  10 import matplotlib.pyplot as plt
  11 import sys
  12 import re
  13
  14 # example usage:
  15 # build/bin/ulp -e .0001 log 0.5 2.0 2345678 | math/tools/plot.py
  16
  17
  18 def fhex(s):
  19     return float.fromhex(s)
  20
  21
  22 def parse(f):
  23     xs = []
  24     gs = []
  25     ys = []
  26     es = []
  27     # Has to match the format used in ulp.c
  28     r = re.compile(r"[^ (]+\(([^ )]*)\) got ([^ ]+) want ([^ ]+) [^ ]+ ulp err ([^ ]+)")
  29     for line in f:
  30         m = r.match(line)
  31         if m:
  32             x = fhex(m.group(1))
  33             g = fhex(m.group(2))
  34             y = fhex(m.group(3))
  35             e = float(m.group(4))
  36             xs.append(x)
  37             gs.append(g)
  38             ys.append(y)
  39             es.append(e)
  40         elif line.startswith("PASS") or line.startswith("FAIL"):
  41             # Print the summary line
  42             print(line)
  43     return xs, gs, ys, es
  44
  45
  46 def plot(xs, gs, ys, es):
  47     if len(xs) < 2:
  48         print("not enough samples")
  49         return
  50     a = min(xs)
  51     b = max(xs)
  52     fig, (ax0, ax1) = plt.subplots(nrows=2)
  53     es = np.abs(es)  # ignore the sign
  54     emax = max(es)
  55     ax0.text(a + (b - a) * 0.7, emax * 0.8, "%s\n%g" % (emax.hex(), emax))
  56     ax0.plot(xs, es, "r.")
  57     ax0.grid()
  58     ax1.plot(xs, ys, "r.", label="want")
  59     ax1.plot(xs, gs, "b.", label="got")
  60     ax1.grid()
  61     ax1.legend()
  62     plt.show()
  63
  64
  65 xs, gs, ys, es = parse(sys.stdin)
  66 plot(xs, gs, ys, es)