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Truncating in SimpleIDE — Parallax Forums

Truncating in SimpleIDE

BWaytBWayt Posts: 6
in Propeller 2

Not sure if this is the correct place to post this, if not please let me know!
I'm trying to use trunc() in SimpleIDE to round to a few decimal places, but the compiler tells me, "bad function call 'trunc', as if it doesn't recognize the function. But I know trunc is working because if I put, say, trunc(2.44) in, it compiles just fine.
The puzzling thing is that if I change _time_sweep's data type from double to int, it compiles just fine- as if the double type cast didn't happen, and it's treating test as an int. Can anyone give me a clue? I have been stuck on this for some time now.

c
c
orientation_Test.c
1K

Comments

  • Wuerfel_21Wuerfel_21 Posts: 4,540

    Try adding an #include <math.h>.

  • BWaytBWayt Posts: 6

    I have tried this (it was what my professor recommended I do first as well), but it changed nothing. Also, doesn't "simpletools.h" include "math.h"?

  • Dave HeinDave Hein Posts: 6,347

    I suspect that the trunc() function isn't in the library. trunc(2.44) works because the compiler evaluates this to 2.0 at compile time without adding a call to trunc() at runtime. You could use (double)(int)x, which would be the same as trunc(x) as long as the integer part fits within a 32-bit integer.

    I see that the only place you use the trunc() function is in the line "time_sweep = trunc((double)theta);". Since theta is an int, it is already truncated to an integer. You would get the same result with "time_sweep = (double)theta;".

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