fortran-approx

Description

This repository provides approx.F90, a simple Fortran module. It enables approximate comparisons analogous to the standard relational operators .eq., .ne., .lt., .le., .gt., and .ge.. The default tolerance is 1.0e-10, and it can be changed either by modifying the module or by passing an argument to the function.

In addition, the following custom operators are provided: .aeq., .sne., .slt., .ale., .sgt., and .age. These operators perform comparisons that honor the module's tolerance. They use the same tolerance value, which can be changed only by modifying the module.

Available functions and operators

Functions

• approx_eq(x, y, tol)
• strict_ne(x, y, tol)
• strict_lt(x, y, tol)
• approx_le(x, y, tol)
• strict_gt(x, y, tol)
• approx_ge(x, y, tol)

The argument tol can be ignored.

Operators

• .approx.
• .aeq. (alias of .approx.)
• .sne.
• .slt.
• .ale.
• .sgt.
• .age.

Roadmap

• Provide variants without optional arguments to reduce runtime overhead
• Publish as a static/shared library
• Set the default tolerance to a combined absolute + relative form (abs_tol + rel_tol style)