It only seems to have been mentioned a couple of times in passing, but Alan Eliasen's Frink
is an incredibly useful tool for doing physical calculations. It handles any combination of thousands of built-in units
and constants (converting to SI internally then back to any desired target units. User-defined units may be added, too.) Very good time and calandar functions, with astronomical functions and units, leap seconds (or not, if you prefer). It uses arbitrary-precision math or rational numbers when possible. It has advanced interval arithmetic to keep track of error bounds, if desired. Complex math. Arbitrarily-dimensional, non-rectangular, heterogeneous arrays (but not matrix math, only a little symbolic algebra, no calculus to speak of.)
It runs on anything with a JVM. It installs with just a couple of clicks on regular computers of any OS as well as smartphones, or it can be used via a web interface. It has been under development for several years and still gets multiple updates nearly every week, so it has reached a good state of refinement. It can act as an interactive desk calculator with a terminal-window like interface and command and results history, or as a serious programming tool with GUI, graphics, self-evaluation, anonymous functions, regexp, some OOP, Java introspection etc., etc.
Many other features that are often useful but not explicitly physics-oriented are also built-in, such as working with currency conversions, historical inflation-adjusted values of the dollar and the the GB pound, natural language translations, number theory functions, arithmetic in bases up to 36.
One tip: while it has a very predictable order of operations, it isn't always what you meant. Use parentheses to keep units and numbers together in a denominator, or parts of fractions together in exponents.
I have pasted in the list of features from the introduction on the Frink webpage
, but it is worth taking a look through the documentation there, especially the examples at the bottom to see just how powerful and east to use it is. It's also worth looking at the units data file
- I never knew there were so many weird ones! (What do you measure in sturgeons? in crocodiles? Read and find out.) Some of them have amusing comments -he's scathing about the candela.