fix: getMean too displayBuffer

Author: florian6973

Plugins/LfpDisplayNode/LfpDisplayCanvas.cpp

@@ -1557,14 +1557,16 @@ float LfpDisplaySplitter::getMean(int chan)
 
     // use 0.1s of sample to compute Mean and Std
     float totalPoints = 0.1 * sampleRate;
-
-    // avoid crash if no signal
-    if ((displayBufferIndex[chan] - totalPoints) <= 0)
-        return 0;
 
     for (int samp = displayBufferIndex[chan] - totalPoints; samp < displayBufferIndex[chan]; samp += 1)
     {
-        sample = *displayBuffer->getReadPointer(chan, samp);
+        float sample = 0;
+
+        if (samp >= 0) // read the beginning of the buffer
+            sample = *displayBuffer->getReadPointer(chan, samp);
+        else // read the end of the buffer if negative index
+            sample = *displayBuffer->getReadPointer(chan, displayBuffer->getNumSamples() - samp);
+
         total += sample;
         numPts++;
     }
@@ -1586,14 +1588,14 @@ float LfpDisplaySplitter::getStd(int chan)
 
     for (int samp = displayBufferIndex[chan] - totalPoints; samp < displayBufferIndex[chan]; samp += 1)
     {
-        float value = 0;
+        float sample = 0;
 
         if (samp >= 0) // read the beginning of the buffer
-            value = *displayBuffer->getReadPointer(chan, samp);
+            sample = *displayBuffer->getReadPointer(chan, samp);
         else // read the end of the buffer if negative index
-            value = *displayBuffer->getReadPointer(chan, displayBuffer->getNumSamples() - samp);
+            sample = *displayBuffer->getReadPointer(chan, displayBuffer->getNumSamples() - samp);
 
-        std += pow((value - mean),2);
+        std += pow((sample - mean),2);
         numPts++;
     }
     LOGD("\tReturning ", sqrt(std / numPts));