absolute value?

I don't have a CBC on me right now to test with, but I'm fairly sure I've used abs() with no issues. What firmware are you using? NHS Patchset or official? Modded in any other way e.g. CBCJVM or CBCLua? Any test code you can provide?

Sorry for the delay in replying.
I believe I was using the NHS patchset at the time I had this specific issue (the compiled binary). But I do now recall having the same issue last year with the standard KISS firmware, which would explain why someone wrote a new function that returns the magnitude of a floating point variable. The syntax I tried was like

float c=-1.1;
float a=abs(c);
printf("%f",a);

which returned something other than 1.1.

Like I said it's not a critical issue because I discovered a more efficient way to calculate wheel distances for turning without any function calls, but it is in interesting bug nonetheless. Maybe the math.h abs() function is not typed for float? I know C doesn't allow overloading but you would think they would have typed it for floating-point vars.

Wait nevermind b/c that would result in a compiler error...

Hey Adam, sorry for the delayed reply (giving a talk at a conference seems to cause me to have no free time for the week or so beforehand).

In C++, abs() is defined for both integers and floating-points. In C, I think abs() is only defined for ints. In C, if you want the absolute value of a float, use the fabs() function (which is also available in C++). I'm not entirely sure why you didn't get a compile error though.

Anyway, try fabs() and see if that helps. It's in math.h. Let me know if you have any luck.

A compiler error should've occurred if you tried to use the abs() with a floating point value. Use fabs().

If all else fails, just write your own. :)