Heatmap not drawn on assigning different point strength to different points

[anujshah1003]

No description provided.

[anujshah1003]

I itried assigning different point strength to different points but the heatmap is not being drawn in that case. Below is my code:

class PILGreyHeatmapper(GreyHeatMapper):

def __init__(self, point_diameter, point_strength):
    super().__init__(point_diameter, point_strength)
def heatmap(self, width, height, points,point_strength_type):
    heat = Image.new('L', (width, height), color=255)
    dot = (Image.open(_asset_file('450pxdot.png')).copy()
                .resize((self.point_diameter, self.point_diameter), resample=Image.ANTIALIAS))
    if point_strength_type =='fixed':
        dot = _img_to_opacity(dot, self.point_strength)
        for x, y in points:
            x, y = int(x - self.point_diameter/2), int(y - self.point_diameter/2)
            heat.paste(dot, (x, y), dot)
    elif point_strength_type=='variable':
        for i in range(len(points)):
            print ('point strength: ',self.point_strength[i] )
            dot = _img_to_opacity(dot, self.point_strength[i])
            x,y = points[i][0],points[i][1]
            x, y = int(x - self.point_diameter/2), int(y - self.point_diameter/2)
            heat.paste(dot, (x, y), dot)
    return heat