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{math} {#language.function.math}
======
`{math}` allows the template designer to do math equations in the
template.
- Any numeric template variables may be used in the equations, and the
result is printed in place of the tag.
- The variables used in the equation are passed as parameters, which
can be template variables or static values.
- +, -, /, \*, abs, ceil, cos, exp, floor, log, log10, max, min, pi,
pow, rand, round, sin, sqrt, srans and tan are all valid operators.
Check the PHP documentation for further information on these
[math](&url.php-manual;eval) functions.
- If you supply the `assign` attribute, the output of the `{math}`
function will be assigned to this template variable instead of being
output to the template.
> **Note**
>
> `{math}` is an expensive function in performance due to its use of the
> php [`eval()`](&url.php-manual;eval) function. Doing the math in PHP
> is much more efficient, so whenever possible do the math calculations
> in the script and [`assign()`](#api.assign) the results to the
> template. Definitely avoid repetitive `{math}` function calls, eg
> within [`{section}`](#language.function.section) loops.
Attribute Name Type Required Default Description
---------------- --------- ---------- --------- --------------------------------------------------
equation string Yes *n/a* The equation to execute
format string No *n/a* The format of the result (sprintf)
var numeric Yes *n/a* Equation variable value
assign string No *n/a* Template variable the output will be assigned to
\[var \...\] numeric Yes *n/a* Equation variable value
**Example a:**
{* $height=4, $width=5 *}
{math equation="x + y" x=$height y=$width}
The above example will output:
9
**Example b:**
{* $row_height = 10, $row_width = 20, #col_div# = 2, assigned in template *}
{math equation="height * width / division"
height=$row_height
width=$row_width
division=#col_div#}
The above example will output:
100
**Example c:**
{* you can use parenthesis *}
{math equation="(( x + y ) / z )" x=2 y=10 z=2}
The above example will output:
6
**Example d:**
{* you can supply a format parameter in sprintf format *}
{math equation="x + y" x=4.4444 y=5.0000 format="%.2f"}
The above example will output:
9.44