1 files changed, 50 insertions, 0 deletions
diff --git a/lin_reg.py b/lin_reg.py
new file mode 100644
index 0000000..8fb88b2
--- /dev/null
+++ b/lin_reg.py
@@ -0,0 +1,50 @@
+#!/usr/bin/python
+#/usr/local/bin/python2.7
+
+import numpy as np
+
+
+def main():
+
+    dataz = np.genfromtxt('example.csv', delimiter=',', names=True)
+
+    y = dataz['attitude']
+    x = dataz['correct']
+    print 'x = {} {}'.format(x, np.mean(x))
+    print 'y = {} {}'.format(y, np.mean(y))
+
+    delta_x = x - np.mean(x)
+    delta_y = y - np.mean(y)
+    delta_xy = delta_x*delta_y
+    delta2_x = delta_x**2
+    delta2_y = delta_y**2
+    #print 'delta_x = {} {}'.format(delta_x, np.sum(delta_x))
+    #print 'delta_y = {} {}'.format(delta_y, np.sum(delta_y))
+    #print 'delta_xy = {} {}'.format(delta_xy, np.sum(delta_xy))
+    #print 'delta2_x = {} {}'.format(delta2_x, np.sum(delta2_x))
+    #print 'delta2_y = {} {}'.format(delta2_y, np.sum(delta2_y))
+
+    sx = np.sqrt(np.sum(delta2_x)/(delta2_x.size - 1))
+    sy = np.sqrt(np.sum(delta2_y)/(delta2_y.size - 1))
+    r = np.sum(delta_xy)/np.sqrt(np.sum(delta2_x)*np.sum(delta2_y))
+    #print 'sx = {}'.format(sx)
+    #print 'sy = {}'.format(sy)
+    print 'r = {}'.format(r)
+    print 'r^2 = {}'.format(r**2)
+
+    b = r*(sy/sx)
+    a = np.mean(y) - b*np.mean(x)
+    print 'b = {}'.format(b)
+    print 'a = {}'.format(a)
+
+    err = y - (a + b*x)
+    b_err = np.sqrt(np.sum(err**2.0)/((x.size - 2)*np.sum(delta2_x)))
+    a_err = np.sqrt(np.sum(x**2.0)*np.sum(err**2.0)/(x.size*(x.size - 2)*np.sum(delta2_x)))
+    print 'b_err = {}'.format(b_err)
+    print 'a_err = {}'.format(a_err)
+
+    print '  (attitude) \t= {}(correct) + {}'.format(b, a)
+
+
+if __name__ == '__main__':
+    main()