*log10* reads its standard input, which should be in text form
and should contain two positive numbers (x and y) on each line, separated
by spaces or tabs. The standard output of *log10* contains four columns
of numbers, separated by spaces: the common (base 10) logarithms of x
and y, and the x and y values. To avoid underflow, if any input is less
than MINDOUBLE (defined in *<values.h>* as the smallest positive value that
can be represented as a double-precision floating point quantity), it is
replaced by that value.

This program is part of the *psd* package,
distributed with the DB Software Package, version 9.3 and later.