CMath — Evaluate a math expression at the command line.
To evaluate a math expression, type a colon followed by the expression. Then press Enter:
:1+2*3
The answer, 7, will be displayed below your expression. It will also
be saved to the environment variable ANS
. You can use this
variable in your next expression:
:ans*2
Just remember that the value of ANS
changes every time you
use CMath. After the second line, ANS
will be 14, not 7.
CMath calls the same function that @EVAL
uses internally.
You can use any operator or function that is legal in @EVAL
:
:log(100)
set r=4
:pi*r**2
You do not need to quote or escape special characters:
:(1+2)*3
:1 << 8
:1024 >> 3
:5 & 9
:5 | 9
:5 ^ 9
The one special character which needs attention is the percent
sign. If you want to use a percent sign as the modulo operator,
you will need to double it. (But it’s probably easier just
to type MOD
.)
:100%%7
:100 mod 7
You do not need a percent sign before environment variables. You do need a percent sign before internal variables and variable functions:
:%_pid =x
:3 * %@dec[foo]
@EVAL
’s built-in functions do not take a percent
sign:
set n=52
set r=5
:fact(n) / fact(n-r) / fact(r)