52 lines
1.1 KiB
Nim
52 lines
1.1 KiB
Nim
import sequtils, strutils
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type Matrix[N: static int; T] = array[1..N, array[1..N, T]]
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func `*`[N, T](a, b: Matrix[N, T]): Matrix[N, T] =
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for i in 1..N:
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for j in 1..N:
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for k in 1..N:
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result[i][j] += a[i][k] * b[k][j]
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func identityMatrix[N; T](): Matrix[N, T] =
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for i in 1..N:
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result[i][i] = T(1)
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func `^`[N, T](m: Matrix[N, T]; n: Natural): Matrix[N, T] =
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if n == 0: return identityMatrix[N, T]()
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if n == 1: return m
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var n = n
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var m = m
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result = identityMatrix[N, T]()
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while n > 0:
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if (n and 1) != 0:
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result = result * m
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n = n shr 1
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m = m * m
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proc `$`(m: Matrix): string =
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var lg = 0
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for i in 1..m.N:
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for j in 1..m.N:
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lg = max(lg, len($m[i][j]))
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for i in 1..m.N:
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echo m[i].mapIt(align($it, lg)).join(" ")
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when isMainModule:
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let m1: Matrix[3, int] = [[ 3, 2, -1],
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[-1, 0, 5],
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[ 2, -1, 3]]
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echo m1^10
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import math
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const
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C30 = sqrt(3.0) / 2
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S30 = 1 / 2
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let m2: Matrix[2, float] = [[C30, -S30], [S30, C30]] # 30° rotation matrix.
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echo m2^12 # Nearly the identity matrix.
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