initial commit

tools/fastcos.py

@@ -0,0 +1,19 @@
+import math
+def sin(x):
+    B = 5215 # int((4.0/math.pi)*4096)
+    C = -1660 # int((-4.0/(math.pi*math.pi))*4096)
+    Q = 3174 # 0.775
+    P = 922 # 0.225
+    y = (B*x + ((C*x)>>12)*abs(x))>>12
+    y = (((P * (((y * abs(y))>>12) - y))>>12) + y)
+    return y
+
+
+n = 200
+for x in xrange(n):
+    i = -math.pi + x/100.0*math.pi
+    
+    print "==== " + str(i)
+    print "fixed : " + str(int(sin(int(i*4096.0))))
+    print "math  : " + str(int(math.sin(i)*4096.0))
+