diff options
Diffstat (limited to 'test/cubic_interpolation')
| -rwxr-xr-x | test/cubic_interpolation | 15 |
1 files changed, 10 insertions, 5 deletions
diff --git a/test/cubic_interpolation b/test/cubic_interpolation index 249aa89..6d2b22c 100755 --- a/test/cubic_interpolation +++ b/test/cubic_interpolation @@ -12,13 +12,16 @@ print('Loading matplotlib.pyplot...') import matplotlib.pyplot as plot print('Done loading matplotlib.pyplot') +from math import * + def main(): # Create a page with graphs fig = plot.figure() # Add graphs - add_graph(fig, 111, [i / 15 for i in range(16)]) + add_graph(fig, 211, [i / 15 for i in range(16)]) + add_graph(fig, 212, [sin(6 * i / 15) for i in range(16)]) # Show graphs plot.show() @@ -45,7 +48,7 @@ def add_graph(fig, graph_pos, input_values): graph.plot([i / (n - 1) for i in range(n)], input_values, 'ro') -def interpolate(small): +def interpolate(small, tension = 0): ''' Interpolate data @@ -56,8 +59,8 @@ def interpolate(small): small_, large_ = len(small) - 1, len(large) - 1 # Basis functions h00 = lambda t : (1 + 2 * t) * (1 - t) ** 2 - h01 = lambda t : t * (1 - t) ** 2 - h10 = lambda t : t ** 2 * (3 - 2 * t) + h10 = lambda t : t * (1 - t) ** 2 + h01 = lambda t : t ** 2 * (3 - 2 * t) h11 = lambda t : t ** 2 * (t - 1) def tangent(values, index, last): ''' @@ -72,6 +75,8 @@ def interpolate(small): if index == 0: return values[1] - values[0] if index == last: return values[last] - values[last - 1] return (values[index + 1] - values[index - 1]) / 2 + # Tension coefficent + c_ = 1 - tension for i in range(len(large)): # Scaling j = i * small_ / large_ @@ -80,7 +85,7 @@ def interpolate(small): # Points pj, pk = small[j], small[k] # Tangents - mj, mk = tangent(small, j, small_), tangent(small, k, small_) + mj, mk = c_ * tangent(small, j, small_), c_ * tangent(small, k, small_) # Interpolation large[i] = h00(w) * pj + h10(w) * mj + h01(w) * pk + h11(w) * mk return large |