changed sign

diff --git a/c/goertzel/goertzel.c b/c/goertzel/goertzel.c
index 19bfdf56eec479d9e372c6f1d3067241b0384fa2..d13a874d9612379d94ca4e07c7de72da16ea7294 100644 (file)
--- a/c/goertzel/goertzel.c
+++ b/c/goertzel/goertzel.c
@@ -29,7 +29,7 @@ float goertzel_mag(int numSamples,float TARGET_FREQUENCY,int SAMPLING_RATE, floa
 
     // calculate the real and imaginary results
     // scaling appropriately
-    real = (q2 - q1 * cosine) / scalingFactor;
+    real = (q1 * cosine - q2) / scalingFactor;
     imag = (q1 * sine) / scalingFactor;
 
     magnitude = sqrtf(real*real + imag*imag);