Error on pow() with fractional exponent

Forum 2005-2010 (read only) Hardware Bugs & Suggestions
1

I wanna do that kind of calc:

Example: Cubic Root of 64:

float expo = 1/3;
int cubicRoot = pow(64, expo); //the answer is 4
Serial.println(cubicRoot); //but isn't right... it prints 1

Somebody knows what is the trouble here!? :-[
Do you know another way to do that?

2

640 = 1.
(Because 1 / 3 = 0)

Try
"float expo = 1.0 / 3.0;"
or even
"float expo = 1 / 3.0;"
should be sufficient.

[edit]BTW, this is not a hardware issue.[/edit]

3

Don't forget to "round", or even with Groove's fix you may get "3" rather than 4, because
a float value of 3.9999123 (or whatever) cast to an int truncates...

4

:o Shame on me! LOL

Thank you guys...
It works now! ;D

I put 1.0 / 3... and it works perfectly!

(Sorry... I put that post in wrong place)