25 lines
579 B
Python
25 lines
579 B
Python
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def lagrange_polynom(points, j):
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nom = ""
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dem = 1
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xj = points[j][0]
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for u in range(len(points)):
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if u == j:
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continue
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nom += f"(x - {points[u][0]})"
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dem *= xj - points[u][0]
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return (nom, dem)
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def interpolate_lagrange(points):
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n = len(points)
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poly = ""
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for i in range(n):
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(lagrange, dem) = lagrange_polynom(points, i)
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poly += f" + {points[i][1]*dem}*{lagrange}"
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return poly
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def test():
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points = [[1,2], [3,5], [4,-1]]
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print(f"polynom via lagrange: {interpolate_lagrange(points)}")
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