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 def fhex(s):
  18         return float.fromhex(s)
  19
  20 def parse(f):
  21         xs = []
  22         gs = []
  23         ys = []
  24         es = []
  25         # Has to match the format used in ulp.c
  26         r = re.compile(r'[^ (]+\(([^ )]*)\) got ([^ ]+) want ([^ ]+) [^ ]+ ulp err ([^ ]+)')
  27         for line in f:
  28                 m = r.match(line)
  29                 if m:
  30                         x = fhex(m.group(1))
  31                         g = fhex(m.group(2))
  32                         y = fhex(m.group(3))
  33                         e = float(m.group(4))
  34                         xs.append(x)
  35                         gs.append(g)
  36                         ys.append(y)
  37                         es.append(e)
  38                 elif line.startswith('PASS') or line.startswith('FAIL'):
  39                         # Print the summary line
  40                         print(line)
  41         return xs, gs, ys, es
  42
  43 def plot(xs, gs, ys, es):
  44         if len(xs) < 2:
  45                 print('not enough samples')
  46                 return
  47         a = min(xs)
  48         b = max(xs)
  49         fig, (ax0,ax1) = plt.subplots(nrows=2)
  50         es = np.abs(es) # ignore the sign
  51         emax = max(es)
  52         ax0.text(a+(b-a)*0.7, emax*0.8, '%s\n%g'%(emax.hex(),emax))
  53         ax0.plot(xs,es,'r.')
  54         ax0.grid()
  55         ax1.plot(xs,ys,'r.',label='want')
  56         ax1.plot(xs,gs,'b.',label='got')
  57         ax1.grid()
  58         ax1.legend()
  59         plt.show()
  60
  61 xs, gs, ys, es = parse(sys.stdin)
  62 plot(xs, gs, ys, es)