Round float to nearest integer

Brian Walsh

Other Parts Discussed in Thread: CONTROLSUITE

Hi,

I am searching for a function that rounds my float values to the nearest integer. Unfortunately I could only find a floor() and ceil() function in the math.h.

I am using a F28335.

Thank you in advance.

~ Brian

over 9 years ago

0 Richard Poley over 9 years ago

TI__Mastermind 27200 points

Hi Brian,

You may find this thread helpful: http://e2e.ti.com/support/microcontrollers/c2000/f/171/t/360075

Regards,

Richard

0 Brian Walsh over 9 years ago in reply to Richard Poley

Intellectual 460 points

Hi Richard,

thank you for the answer. It didn't really help me, but as I only want to round positive floats to the nearest integer, for example

29.6 -> 30

30.4 -> 30

I will try it like this:

float x = 29.6;
Uint16 y;

x += 0.5;
y = x;

~Brian

0 Gautam Iyer over 9 years ago in reply to Brian Walsh

Guru 192875 points

You can use this function mentioned here: www.geeksforgeeks.org/.../

0 Keyur Acharya over 9 years ago

Expert 1740 points

you can use floating point library as you have a floating point processor.

C:\TI\controlSUITE\libs\dsp\FPU\VERSION

this is the path of library which you can include.

It has a basic function for rounding float values.

the function name is "rnd_SP_RS(x);"

examples are

rnd_SP_RS(+4.4) = +4.0
rnd_SP_RS(-4.4) = -4.0
rnd_SP_RS(+4.5) = +5.0
rnd_SP_RS(-4.5) = -5.0
rnd_SP_RS(+4.6) = +5.0
rnd_SP_RS(-4.6) = -5.0

and it may be really fast compared to the C function which you can make, as it takes only 18 clock cycles for execution including function calls.

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Round float to nearest integer