How to make the atan2 function available?

[fernest0]

Hi!
In my visit script I want to do a coordinate transformation from Cartesian to polar, so I'm needing the atan2 (arctangent) function, which is usually available as a built-in function in languages such as C and FORTRAN.

What is the easiest way to get it in visIt? It doesn't appear in the built-in expressions, and to use a python expression doesn't seem to be the best way.

Thanks!
Ernesto.

[brugger1]

atan2 is available in VisIt, at least in VisIt 3.3.1, which is what I tried. It is neither documented or listed in the trigonometry functions in the Expressions window. I'll submit a ticket to fix these issues.

[fernest0]

Thank you @brugger1 !

For the sake of completeness, atan2 must be called as atan2(y,x).
The range of atan2 is [-pi,pi], so if you would like to have the range in [0,2pi], as me, it can be done with
if(lte(y,0.0),atan2(y,x)+2.*pi,atan2(y,x))