From Vim Tips Wiki
Here is how to define and use a calculator, using embedded Python.
These two lines go in your vimrc:
:command! -nargs=+ Calc :py print <args> :py from math import *
Now use it inside Vim:
:Calc 2**10+5,2**16,2**128 1029 65536 340282366920938463463374607431768211456 :Calc sin(pi/2), log(10) 1.0 2.302585
You have to have Vim compiled with Python support, and have Python on your machine†. Use
:version to see which features are included in your Vim.
If you don't have Python support in your Vim, but do have a python command, use this instead
command! -nargs=+ Calc :!python -c "from math import *; print <args>"
You also get complex numbers and other goodies. Google for Python and math. Here is an example from complex math:
:py from cmath import * :Calc exp(pi*1j) , " Euler famous identify e^i.pi = -1" (-1+1.22460635382e-016j) :Calc sum(range(1,100+1)), "Gauss' famous identity sum(1,100)" 5050
These days, Vim Python support in Windows is usually via a dll, installed separately from Vim:
+python/dyn. Go to http://python.org/ to get the Python installer.
To check whether you have Python software that Vim can use (either statically linked or dynamically findable), do
:echo has('python') — 0 (zero) means "no", anything else (normally 1) means "yes".
If your Vim (7.2 or later) is compiled with +float, you can do scientific calculations in Vim even without Python.
- Use the numeric operators (except %) and floating point functions defined by Vim, see
- Exponentiation is pow(base,exponent), not
- :echo gives you 6-digit precision by default, use printf() for user-specified precision, up to about 15 significant digits on an Intel PC (I don't know how many on a Mac PPC or an an IBM System-z).
- If you can lay hands on (or compile) a Vim patched with Bill McCarthy's additional floating-point functions (#7 in the list), you won't need to know trigonometric formulas for "missing" functions such as tan(), asin(), atan2() etc., and you'll be able to use
exp(1)rather than a literal value for e.