math

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

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 functions.

If you supply the special "assign" attribute, the output of the math function will be assigned to this template variable instead of being output to the template.

Technical Note: math is an expensive function in performance due to its use of the php eval() function. Doing the math in PHP is much more efficient, so whenever possible do the math calculations in PHP and assign the results to the template. Definately avoid repetitive math function calls, like within section loops.

Example 8-14. math

{* $height=4, $width=5 *}

{math equation="x + y" x=$height y=$width}

OUTPUT:

9


{* $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#}

OUTPUT:

100


{* you can use parenthesis *}

{math equation="(( x + y ) / z )" x=2 y=10 z=2}

OUTPUT:

6


{* you can supply a format parameter in sprintf format *}

{math equation="x + y" x=4.4444 y=5.0000 format="%.2f"}

OUTPUT:

9.44