Low Pass filter

Thread Starter


Joined Sep 18, 2008
Hi guys, i have simple low pass filter program, i do not know what "double µ = t / (t + constant);" mean here

double µ = t / (t + constant);

double input[10000];
double output[10000];

double output[0] = input[0];
while(for t=1; t<10000])
output[t] = µ * (input[t] - output[t-1]) + output[t-1];



Joined Oct 27, 2010
Is this written in C, C++, C# (Sharp) or Java? I am a C/C++ programmer so I am not familiar with that u looking type of symbol. In normal C/C++ syntax, t and constant would have to be a variable declared elsewhere (not shown) in the program.

If so, that line would read. Declare a variable name u and assign the value of the expression... t / (t + constant) to it.

t here probably mean time constant. (RxC) not sure why it is written like that in the program.

I have written filter programs for Windows CE, using Visual C++/MFC. It calculates impedance, phase angle, cutoff frequency, XC, XL, AV (gain), and time constant, and I never have to structure my program like that.
Last edited: