+void SetLogFilename(char *fn) {
+ logfilename = fn;
+}
+
+void iceIIR_Butterworth(int *data, const size_t len){
+
+ int i,j;
+
+ int * output = (int* ) malloc(sizeof(int) * len);
+ memset(output, 0x00, len);
+ float fc = 0.1125f; // center frequency
+ size_t adjustedLen = len;
+
+ // create very simple low-pass filter to remove images (2nd-order Butterworth)
+ float complex iir_buf[3] = {0,0,0};
+ float b[3] = {0.003621681514929, 0.007243363029857, 0.003621681514929};
+ float a[3] = {1.000000000000000, -1.822694925196308, 0.837181651256023};
+
+ float sample = 0; // input sample read from array
+ float complex x_prime = 1.0f; // save sample for estimating frequency
+ float complex x;
+
+ for (i=0; i<adjustedLen; ++i) {