pure python bezier smoothing for matplotlib

bezier_smooth_plot.py

"""
For http://stackoverflow.com/q/5255932
"""

def tangent_interpolate(index, x_array, y_array, dist=0.5): 
    before_index = max(index - 1, 0)
    after_index = min(index + 1, len(x_array))
    chord_vector_x = x_array[after_index] - x_array[before_index] 
    chord_vector_y = y_array[after_index] - y_array[before_index]
    if dist>0:
        next_point_x_dist = x_array[after_index] - x_array[index]
    else:
        next_point_x_dist = x_array[index] - x_array[before_index]
    scale_factor = float(next_point_x_dist)/chord_vector_x
    return x_array[index] + dist * scale_factor * chord_vector_x,\
        y_array[index] + dist * scale_factor * chord_vector_y