GNU Calc

GNU Calc does the usual things: arbitrary precision integer, real, and complex arithmetic (all written in Lisp), scientific functions, symbolic algebra and calculus, matrices, graphics, etc. and can display expressions with square root signs and integrals by drawing them on the screen with ascii characters. It's nowhere near as powerful as something like Mathematica, but it is more convenient to use for simple things because of its calculator-like interface. Besides, all source code is available. "Calc" runs inside GNU Emacs and is written entirely in Emacs Lisp, for maximum portability. It comes with a 600 page online manual which is generally well written.

From the introduction to the GNU Calc manual:

"Calc" is an advanced calculator and mathematical tool that runs as part of the GNU Emacs environment. Very roughly based on the HP-28/48 series of calculators, its many features include:

• Choice of algebraic or RPN (stack-based) entry of calculations.
• Arbitrary precision integers and floating-point numbers.
• Arithmetic on rational numbers, complex numbers (rectangular and polar), error forms with standard deviations, open and closed intervals, vectors and matrices, dates and times, infinities, sets, quantities with units, and algebraic formulas.
• Mathematical operations such as logarithms and trigonometric functions.
• Programmer's features (bitwise operations, non-decimal numbers).
• Financial functions such as future value and internal rate of return.
• Number theoretical features such as prime factorization and arithmetic modulo M for any M.
• Algebraic manipulation features, including symbolic calculus.
• Moving data to and from regular editing buffers.
• "Embedded mode" for manipulating Calc formulas and data directly inside any editing buffer.
• Graphics using GNUPLOT, a versatile (and free) plotting program.
• Easy programming using keyboard macros, algebraic formulas, algebraic rewrite rules, or extended Emacs Lisp.

GNU Calc Home Page

Last updated: November 15, 1994