| 0,0 → 1,33 |
|---|
| # compute arctangent table for CORDIC computations in fttrigon.c |
| import sys, math |
| |
| #units = 64*65536.0 # don't change !! |
| units = 180 * 2**16 |
| scale = units/math.pi |
| shrink = 1.0 |
| comma = "" |
| |
| print "" |
| print "table of arctan( 1/2^n ) for PI = " + repr(units/65536.0) + " units" |
| |
| for n in range(1,32): |
| |
| x = 0.5**n # tangent value |
| |
| angle = math.atan(x) # arctangent |
| angle2 = round(angle*scale) # arctangent in FT_Angle units |
| |
| if angle2 <= 0: |
| break |
| |
| sys.stdout.write( comma + repr( int(angle2) ) ) |
| comma = ", " |
| |
| shrink /= math.sqrt( 1 + x*x ) |
| |
| print |
| print "shrink factor = " + repr( shrink ) |
| print "shrink factor 2 = " + repr( int( shrink * (2**32) ) ) |
| print "expansion factor = " + repr( 1/shrink ) |
| print "" |
| |