def curve_draw(self, p0, p1, pt_list, line_width=3):
# pt_list.remove(pt_list[0])
# pt_list.remove(pt_list[-1])
xList = []
yList = []
param = len(pt_list)
pdt = p0 - p1
p = Pixel(0, 0)
draw = ImageDraw.Draw(self.image)
for i in range(param):
temp_pt = Pixel(pt_list[i][0], pt_list[i][1])
p.x = p0.x + pdt.x * temp_pt.x
p.y = temp_pt.y
xList.append(p.x)
yList.append(p.y)
# if i < param + 1:
# draw.line((p0.x,p0.y,p.x,p.y), fill=(255,0,0), width=line_width)
# self.curve_pixs.append(Pixel(int(p.x + 0.5), int(p.y + 0.5)))
# p0.x, p0.y = p.x, p.y
# else:
# draw.line((p.x,p.y,p1.x,p1.y), fill=(255,0,0), width=line_width)
# self.curve_pixs.append(Pixel(int(p.x + 0.5), int(p.y + 0.5)))
m = 100000 # of steps
for p in range(m):
x = (self.image.size[0] - 1) * p / (m - 1)
y = 0.0
for j in range(param):
Lx = 1.0
for k in range(param):
if k != j:
Lx = Lx * (x - xList[k]) / (xList[j] - xList[k])
y = y + yList[j] * Lx
if y >= 0 and y <= self.image.size[1] - 1:
self.image.putpixel((int(x), int(y)), (255, 255, 255))
# show the points used
cr = 3 # circle radius
for i in range(param):
cx = int(xList[i])
cy = int(yList[i])
draw.ellipse((cx - cr, cy - cr, cx + cr, cy + cr))
self.image.save('Polynomial_Interpolation.png', 'PNG')
return list(zip(xList, yList))
