log.test.C
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/*ident "@(#)cls4:demo/complex/log.test.C 1.1" */
/*******************************************************************************
C++ source for the C++ Language System, Release 3.0. This product
is a new release of the original cfront developed in the computer
science research center of AT&T Bell Laboratories.
Copyright (c) 1991 AT&T and UNIX System Laboratories, Inc.
Copyright (c) 1984, 1989, 1990 AT&T. All Rights Reserved.
THIS IS UNPUBLISHED PROPRIETARY SOURCE CODE of AT&T and UNIX System
Laboratories, Inc. The copyright notice above does not evidence
any actual or intended publication of such source code.
*******************************************************************************/
#include <complex.h>
#include <values.h>
#define NUM_TESTS 8
/*
**************************************************************
*
* j*theta
* log(c), where c = a + bj = r*e , is
*
* = log(r) + j*theta.
*
* thus, we want to pick test cases where log(r) is easy
* to find, like r = e**0 = 1, and r = e**1 = e.
*
* similarily, we pick test cases where the angle theta
* is a nice multiple of PI/4.
*
* eight test cases:
* |
* |
* x
* |(0, PI)
* |
* |
* |
* |
* |
* | x
* | (E/sqrt(2), E/sqrt(2))
* |
* |
* |
* |
* x
* |(0, 1)
* |
* | x
* | (1/sqrt(2), 1/sqrt(2))
* |
* |
* |
* -----x---------------x-----------|----------x----------------x---------
* (-E, 0) (-1, 0) | (1, 0) (1, 0)
* |
* |
* (cartesian coordinates)
*
**************************************************************
*/
main()
{
complex c[NUM_TESTS];
complex ans[NUM_TESTS];
complex d;
c[0] = complex(1, 0); ans[0] = complex(0, 0);
c[1] = complex(1/M_SQRT2, 1/M_SQRT2); ans[1] = complex(0, M_PI_4);
c[2] = complex(0, 1); ans[2] = complex(0, M_PI_2);
c[3] = complex(-1, 0); ans[3] = complex(0, M_PI);
c[4] = complex(M_E, 0); ans[4] = complex(1, 0);
c[5] = complex(M_E/M_SQRT2, M_E/M_SQRT2);ans[5] = complex(1, M_PI_4);
c[6] = complex(0, M_E); ans[6] = complex(1, M_PI_2);
c[7] = complex(-M_E, 0); ans[7] = complex(1, M_PI);
for ( int i = 0; i < NUM_TESTS; i++ ) {
errno = 0;
d = log(c[i]);
if ( errno ) {
cout << "*** test failed *** log("
<< c[i] << "), errno=" << errno << "\n";
continue;
}
if ( _ABS(real(d) - real(ans[i])) > X_EPS
||
_ABS(imag(d) - imag(ans[i])) > X_EPS ) {
cout << "*** test failed *** log("
<< c[i] << ") = " << d << ", correct answer = "
<< ans[i] << "\n";
}
else
cout << "*** test passed *** log("
<< c[i] << ") = " << d << "\n";
}
return 0;
}