DATAMANIP (kdatamanip) functions


LIBRARY ROUTINE

lklogexp - perform log or antilog function on data object

LIBRARY CALL

int lklogexp (
   kobject i,
   double  base,
   int     offset,
   int     inv,
   kobject o)

INPUT

OUTPUT

RETURN VALUE

TRUE (1) on success, FALSE (0) on failure

DESCRIPTION

lklogexp performs an log/antilog function on a data object. The routine takes an input data object, user specified base, offset flag, and an output data object in which to store the result of the operation.

Therefore if lklogexp() were called with: lklogexp(i, 2.0, TRUE, FALSE, o); then o = log2(i).

If lklogexp() were called with: lklogexp(i, KE, FALSE, TRUE, o); then o = e**(i)-1.

If the input object has a map segment, then the values in the map segment are modified directly according to the requested operation.

If there is no map segment, then the value data is modified directly according to the requested operation. If a mask segment is also present, then only those value points with a non-zero mask are modified.

ADDITIONAL INFORMATION

none

EXAMPLES

none

SIDE EFFECTS

none

RESTRICTIONS

If the argument of the logarithm evaluates to less than or equal to zero, a large negative number (-KMAXFLOAT) is returned.

A complex base is not currently supported.

MODIFICATION

none

FILES

$DATAMANIP/objects/library/kdatamanip/src/lklogexp.c

SEE ALSO

kdatamanip(3)

COPYRIGHT

Copyright (C) 1993 - 1997, Khoral Research, Inc. ("KRI") All rights reserved.