# check_expect_tuple_within_tolerance.py   P. Conrad for CS5NM, Fall 2008
# UC Santa Barbara
#
# This provides a testing function that will work on tuples of floating point numbers

import math # needed for math.fabs function

# check_expect_within_tolerance
#    checks whether a function produces the expected result
#    but allows some degree of inaccuracy (a "tolerance")
#    in cases where calculating the exact result may not be feasible
#    (e.g. quantities involving pi, square roots, etc.)
# consumes:
#        test: a string describing the test
#       check: the value we are testing (typically result of a function call)
#      expect: the value we are expecting (typically a literal value)
#  toleranace: the largest inaccuracy that is permitted
# produces:
#    nothing (there is no return value)
# side effect:
#    prints a message indicating whether the test passed or failed


def check_expect_within_tolerance(test,check,expect,tolerance):
    if (math.fabs(check-expect) <= tolerance):
        print "Test " + test + " passed (with tolerance " + \
              str(tolerance) + ")"
    else:
        print "Test " + test + " failed: expected " + str(expect)  + \
              " but I got " + str(check) + " (tolerance of  " + \
            str(tolerance) + " exceeded)"



# check_expect_tuple_within_tolerance
#    checks whether a function produces the expected result
#    but allows some degree of inaccuracy (a "tolerance")
#    in cases where calculating the exact result may not be feasible
#    (e.g. quantities involving pi, square roots, etc.)
# consumes:
#        test: a string describing the test
#       check: the tuple we are testing (typically result of a function call)
#      expect: the tuple we are expecting (typically a literal value)
#  toleranace: the largest inaccuracy that is permitted
# produces:
#    nothing (there is no return value)
# side effect:
#    prints a message indicating whether the test passed or failed


def check_expect_tuple_within_tolerance(test,check,expect,tolerance):
    # assume that the test will pass--we'll set fail to True if we find a problem
    fail = False; 
    message = "" # This is the message we print if the test fails

    if (len(expect)!=len(check)):
       fail = True;
       message = "Lengths don't match... length of expect tuple = " + str(len(expect)) + \
          ", but length of check tuple is " + str(len(check))
    else:
        length = len(check) # I now know that that is also the length of expect

        for i in range(length):
            if (math.fabs(check[i]-expect[i]) > tolerance):
                # if that was true, then the test failed
                fail = True;
                message += " check[" + str(i) + "] doesn't match expect[" + str(i) + "]\n"

    if (not fail):
        print "Test " + test + " passed (with tolerance " + \
              str(tolerance) + ")"
    else:
        print "Test " + test + " failed: " + " failed: expected " + str(expect)  + \
              " but I got " + str(check) + " (tolerance of  " + \
            str(tolerance) + " exceeded)\n" + message


check_expect_tuple_within_tolerance("This should pass",(1,2,3),(1,2,3),0.001)
check_expect_tuple_within_tolerance("This should fail, different lengths",(1,2,3),(1,2,3,4),0.001)
check_expect_tuple_within_tolerance("This should fail, different lengths",(1,2,3,4),(1,2,3),0.001)

check_expect_tuple_within_tolerance("This should pass",(1,2,3),(0.999,1.9999,3.0001),0.01)
check_expect_tuple_within_tolerance("This should fail",(1,2,3),(1,2,4),0.01)
check_expect_tuple_within_tolerance("This should fail",(1,2,3),(3,2,1),0.01)
check_expect_tuple_within_tolerance("This should fail",(1,2,3),(5,2,3),0.01)

check_expect_tuple_within_tolerance("This should pass",[1,2,3],(1,2,3),0.001)
check_expect_tuple_within_tolerance("This should fail, different lengths",[1,2,3],(1,2,3,4),0.001)
check_expect_tuple_within_tolerance("This should fail, different lengths",[1,2,3,4],(1,2,3),0.001)

check_expect_tuple_within_tolerance("This should pass",[1,2,3],(0.999,1.9999,3.0001),0.01)
check_expect_tuple_within_tolerance("This should fail",[1,2,3],(1,2,4),0.01)
check_expect_tuple_within_tolerance("This should fail",[1,2,3],(3,2,1),0.01)
check_expect_tuple_within_tolerance("This should fail",[1,2,3],(5,2,3),0.01)