Move library tree where it belongs

lib-src/libscorealign/regression.cpp

@@ -0,0 +1,49 @@
+// Regression is a class to compute a linear regression
+// 
+#include "regression.h"
+
+
+Regression::Regression()
+{
+    init();
+}
+
+void Regression::init()
+{
+    sumxx = 0;
+    sumyy = 0;
+    sumxy = 0;
+    sumx = 0;
+    sumy = 0;
+    n = 0;
+}
+
+void Regression::point(float x, float y)
+{
+    sumx = sumx + x;
+    sumy = sumy + y;
+    sumxx = sumxx + x * x;
+    sumyy = sumyy + y * y;
+    sumxy = sumxy + x * y;
+    n = n + 1;
+}
+
+void Regression::regress()
+{
+    float sxx = sumxx - sumx * sumx / n;
+    float sxy = sumxy - sumx * sumy / n;
+    b = sxy / sxx;
+    a = (sumy - b * sumx) / n;
+}
+
+
+float Regression::f(float x)
+{
+    return a + b * x;
+}
+
+
+float Regression::f_inv(float y)
+{
+    return (y - a) / b;
+}