abs() seems not working correctly

[li li]

Hi Guys,

I found an very interesting situation. When I use abs() to find absolute value
of the number, the abs() return the values as function floor() did in MATLAB.
I am not sure it is designed on purpose or it is a bug. If anyone know it,
please let me know. I am looking forward to your response. See below the
examples. The first values is the original value, and the second is the abs
value.

llr:0.460886

abs_llr:0

llr:0.499698

abs_llr:0

llr:0.808538

abs_llr:0

llr:-0.503686

abs_llr:0

llr:-3.66944

abs_llr:3

llr:0.139525

abs_llr:0

llr:0.53825

abs_llr:0

llr:0.154884

abs_llr:0

llr:-4.47081

abs_llr:4

llr:4.52294

abs_llr:4

llr:-0.585991

abs_llr:0

llr:0.559954

abs_llr:0

llr:4.4835

abs_llr:4

llr:0.530505

abs_llr:0

llr:0.601909

abs_llr:0

llr:-0.74995

abs_llr:0

[Laurent Schmalen]

abs() is not a feature of IT++ but of the C++ math library. Unfortunately,
abs() only accepts integers at its input and outputs an integer, in your case,
an implicit typecast is performed, which is why you see rounded values.

Try replacing abs(x) by fabs(x) and it should work