数值回归测试 [英] Numerical regression testing

问题描述

我正在研究一个科学的计算代码（用C ++编写），除了对较小的组件进行单元测试，我想对一些数字输出进行回归测试，通过比较一个已知 - 好答案从以前的修订。我想要一些功能：

I'm working on a scientific computing code (written in C++), and in addition to performing unit tests for the smaller components, I'd like to do regression testing on some of the numerical output by comparing to a "known-good" answer from previous revisions. There are a few features I'd like:

• 允许将数字与指定的容差（对于四舍五入错误和较宽松的期望） li>
  
• 能区分整数，双精度等，并在必要时忽略文本


• 良好格式化的输出， c>或 EXIT_FAILURE code>取决于文件是否匹配



• Allow comparing numbers to a specified tolerance (for both roundoff error and looser expectations)
• Ability to distinguish between ints, doubles, etc, and to ignore text if necessary
• Well-formatted output to tell what went wrong and where: in a multi-column table of data, only show the column entry that differs
• Return EXIT_SUCCESS or EXIT_FAILURE depending on whether the files match

有没有任何好的脚本或应用程序，不得不在Python中自己滚动来读取和比较输出文件？当然，我不是第一个有这些要求的人。

Are there any good scripts or applications out there that do this, or will I have to roll my own in Python to read and compare output files? Surely I'm not the first person with these kind of requirements.

[以下不是严格相关，但它可能会决定什么做。我使用CMake及其嵌入式CTest功能来驱动使用Google Test框架的单元测试。我想我不应该在我的 CMakeLists.txt 中添加一些 add_custom_command 语句来调用任何回归]

[The following is not strictly relevant, but it may factor into the decision of what to do. I use CMake and its embedded CTest functionality to drive unit tests that use the Google Test framework. I imagine that it shouldn't be hard to add a few add_custom_command statements in my CMakeLists.txt to call whatever regression software I need.]

推荐答案

我最终编写了一个Python脚本来做更多或更少的工作。

I ended up writing a Python script to do more or less what I wanted.

#!/usr/bin/env python

import sys
import re
from optparse import OptionParser
from math import fabs

splitPattern = re.compile(r',|\s+|;')

class FailObject(object):
    def __init__(self, options):
        self.options = options
        self.failure = False

    def fail(self, brief, full = ""):
        print ">>>> ", brief
        if options.verbose and full != "":
            print "     ", full
        self.failure = True


    def exit(self):
        if (self.failure):
            print "FAILURE"
            sys.exit(1)
        else:
            print "SUCCESS"
            sys.exit(0)

def numSplit(line):
    list = splitPattern.split(line)
    if list[-1] == "":
        del list[-1]

    numList = [float(a) for a in list]
    return numList

def softEquiv(ref, target, tolerance):
    if (fabs(target - ref) <= fabs(ref) * tolerance):
        return True

    #if the reference number is zero, allow tolerance
    if (ref == 0.0):
        return (fabs(target) <= tolerance)

    #if reference is non-zero and it failed the first test
    return False

def compareStrings(f, options, expLine, actLine, lineNum):
    ### check that they're a bunch of numbers
    try:
        exp = numSplit(expLine)
        act = numSplit(actLine)
    except ValueError, e:
#        print "It looks like line %d is made of strings (exp=%s, act=%s)." \
#                % (lineNum, expLine, actLine)
        if (expLine != actLine and options.checkText):
            f.fail( "Text did not match in line %d" % lineNum )
        return

    ### check the ranges
    if len(exp) != len(act):
        f.fail( "Wrong number of columns in line %d" % lineNum )
        return

    ### soft equiv on each value
    for col in range(0, len(exp)):
        expVal = exp[col]
        actVal = act[col]
        if not softEquiv(expVal, actVal, options.tol):
            f.fail( "Non-equivalence in line %d, column %d" 
                    % (lineNum, col) )
    return

def run(expectedFileName, actualFileName, options):
    # message reporter
    f = FailObject(options)

    expected  = open(expectedFileName)
    actual    = open(actualFileName)
    lineNum   = 0

    while True:
        lineNum += 1
        expLine = expected.readline().rstrip()
        actLine = actual.readline().rstrip()

        ## check that the files haven't ended,
        #  or that they ended at the same time
        if expLine == "":
            if actLine != "":
                f.fail("Tested file ended too late.")
            break
        if actLine == "":
            f.fail("Tested file ended too early.")
            break

        compareStrings(f, options, expLine, actLine, lineNum)

        #print "%3d: %s|%s" % (lineNum, expLine[0:10], actLine[0:10])

    f.exit()

################################################################################
if __name__ == '__main__':
    parser = OptionParser(usage = "%prog [options] ExpectedFile NewFile")
    parser.add_option("-q", "--quiet",
                      action="store_false", dest="verbose", default=True,
                      help="Don't print status messages to stdout")

    parser.add_option("--check-text",
                      action="store_true", dest="checkText", default=False,
                      help="Verify that lines of text match exactly")

    parser.add_option("-t", "--tolerance",
                      action="store", type="float", dest="tol", default=1.e-15,
                      help="Relative error when comparing doubles")

    (options, args) = parser.parse_args()

    if len(args) != 2:
        print "Usage: numdiff.py EXPECTED ACTUAL"
        sys.exit(1)

    run(args[0], args[1], options)

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