45 lines
625 B
C++
45 lines
625 B
C++
// Adjunct of a matrix
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#include "stdafx.h"
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#include "defs.h"
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void
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eval_adj(void)
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{
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push(cadr(p1));
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eval();
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adj();
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}
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void
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adj(void)
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{
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int i, j, n;
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save();
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p1 = pop();
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if (istensor(p1) && p1->u.tensor->ndim == 2 && p1->u.tensor->dim[0] == p1->u.tensor->dim[1])
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;
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else
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stop("adj: square matrix expected");
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n = p1->u.tensor->dim[0];
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p2 = alloc_tensor(n * n);
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p2->u.tensor->ndim = 2;
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p2->u.tensor->dim[0] = n;
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p2->u.tensor->dim[1] = n;
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for (i = 0; i < n; i++)
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for (j = 0; j < n; j++) {
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cofactor(p1, n, i, j);
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p2->u.tensor->elem[n * j + i] = pop(); /* transpose */
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}
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push(p2);
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restore();
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} |