From: Joe Ganley SJ2/1 (408)944-7232 <###@###.###>
This does not look like form output to me.


Greetings,

I've noticed a bug (well, a discrepancy :-) in the java.lang.Math package
included in the JDK 1.0 release for Solaris.

Here is source code that exercises the four conditions listed in the API
documentation for java.lang.Math that allegedly throw an ArithmeticException:

---

import java.lang.*;

public class foo extends java.applet.Applet {

  public void init() {
    try {
      System.out.println("log(-1.0) = " + Math.log(-1.0));
      System.out.println("sqrt(-1.0) = " + Math.sqrt(-1.0));
      System.out.println("pow(0.0,-1.0) = " + Math.pow(0.0, -1.0));
      System.out.println("pow(-1.0,0.5) = " + Math.pow(-1.0, 0.5));
    }
    catch (ArithmeticException exc) {
      System.out.println("An ArithmeticException was thrown.");
    }
  } // init()

} // class foo extends java.applet.Applet

---

This outputs:

log(-1.0) = -Inf
sqrt(-1.0) = NaN
pow(0.0,-1.0) = -Inf
pow(-1.0,0.5) = NaN

with no ArithmeticException thrown. While this is perfectly reasonable
behavior, it contradicts the docs, and I think throwing the exception is
probably more useful behavior.

Cheers,

Joe
______________________________________________________________________________
 Joe Ganley, Ph.D. ###@###.###
 Senior Software Engineer (408)944-7232 / fax (408)894-2700
 Cadence Design Systems http://www.cs.virginia.edu/~jlg8k/
 

Here are other examples from duplicate bug report 4038971:

The following math functions are not behaving as specified in the java language specification.

asin, and acos return 0 instead of NaN for arguments with absolute value greater than 1.
log of negative numbers returns negative infinity instead of NaN
pow called with NaN,0 returns Nan instead of 1.0
pow called with 0, -1 returns -infinity instead of infinity
pow called with -0, -4 returns -infinity instead of infinity

Some examples:

asin failed for c000000000000000 = -2 Expected 7ff8000000000000 Got: 0
asin failed for c010000000000000 = -4 Expected 7ff8000000000000 Got: 0

acos failed for c000000000000000 = -2 Expected 7ff8000000000000 Got: 0
acos failed for c010000000000000 = -4 Expected 7ff8000000000000 Got: 0

log failed for c09f400000000000 = -2000 Expected 7ff8000000000000 Got: fff0000000000000
log failed for c09f37883126e979 = -1997.88 Expected 7ff8000000000000 Got: fff0000000000000

pow failed for 7fffffffffffffff , 0 Expected 3ff0000000000000 Got: 7fffffffffffffff
pow failed for 0 , bff0000000000000 Expected 7ff0000000000000 Got: fff0000000000000
pow failed for 8000000000000000 , c010000000000000 Expected 7ff0000000000000 Got: fff0000000000000

timothy.lindholm@Eng 1997-04-08