Diff: Maths.cpp

Revision:

16:691649d8a3da

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/Maths.cpp	Wed Sep 05 07:50:27 2018 +0000
@@ -0,0 +1,55 @@
+#include "Maths.h"
+#include "mbed.h"
+
+int Maths::comp(const void* elem1, const void* elem2)
+{
+    if(*(const float*)elem1 < *(const float*)elem2)
+        return -1;
+    return *(const float*)elem1 > *(const float*)elem2;
+}
+
+float Maths::mean(float *samples, int n, int n2)
+{
+    float sum = 0.0;
+    for (int i=0; i<n2-n; i++) {
+        sum += samples[n+i];
+    }
+    return sum / (float)(n2-n);
+}
+
+float Maths::median(float *samples, int n)
+{
+    qsort(samples, n, sizeof(float), Maths::comp);
+
+    return mean(samples, (n - 1)/2 - 990,(n - 1)/2 + 990);
+}
+
+float Maths::stdev(float data[] , int n)
+{
+    float sum = 0.0, mean2, standardDeviation = 0.0;
+    int i;
+    mean2 = Maths::mean(data,0,n);
+
+    for(i = 0; i < n; ++i)
+        standardDeviation += pow(data[i] - mean2, 2);
+
+    return sqrt(standardDeviation / n);
+}
+
+
+float Maths::meanNoOutliers(float data[] , int n)
+{
+    float mean = Maths::mean(data,0,n);
+    float stdev = Maths::stdev(data,n);
+    float amount = 0;
+    float sum  = 0;
+    for(int i = 0; i < n; ++i) {
+        if (data[i] <= mean + 1*stdev && data[i] >= mean - 1*stdev) {
+            amount ++;
+            sum += data[i];
+        }
+    }
+    return sum/amount;
+
+
+}