From f5e0076a8455eec5b4a515b39202217f8a8b9e71 Mon Sep 17 00:00:00 2001
From: justanothercatgirl <sotov2070@gmail.com>
Date: Sun, 13 Oct 2024 19:28:57 +0300
Subject: Initial commit

---
 matrix.c | 116 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 116 insertions(+)
 create mode 100644 matrix.c

(limited to 'matrix.c')

diff --git a/matrix.c b/matrix.c
new file mode 100644
index 0000000..29c4457
--- /dev/null
+++ b/matrix.c
@@ -0,0 +1,116 @@
+#include "matrix.h"
+
+// Почему так? Числа более рандомные получаются. А ещё это быстро.
+double frand(double min, double max) {
+	double ret = 0;
+	unsigned long *ret_mem = (unsigned long*)&ret;
+	*ret_mem = (	((unsigned long)rand() << 21) 
+			^ (unsigned long)rand()
+		) & ~(1UL << 63);
+	int expa, expb;
+	frexp(min, &expa);
+	frexp(max, &expb);
+	int _exp = rand() % (expb-expa + 2) + expa - 1 ;
+	*ret_mem |= ((unsigned long)abs(_exp) << 52) | 
+		(_exp < 0 ? 0UL << 62 : 1UL << 62);
+	return fmod(ret, max-min) + min;
+}
+
+struct matrix matrix_new(usz rows, usz columns) {
+	double ** data = malloc(rows * sizeof (double*));
+	for (usz i = 0; i < rows; ++i)
+		data[i] = malloc(columns * sizeof (double));
+	return (struct matrix) {
+		.data = data,
+		.rows = rows,
+		.columns = columns,
+	};
+}
+
+void matrix_free(struct matrix m) {
+	for (usz i = 0; i < m.rows; ++i) 
+		free(m.data[i]);
+	free(m.data);
+}
+
+void matrix_print(struct matrix *m) {
+	for (usz i = 0; i < m->rows; ++i) {
+		printf("| ");
+		for (usz j = 0; j < m->columns; ++j) {
+			printf("%10.3g ", m->data[i][j]);
+		}
+		printf("|\n");
+	}
+}
+
+void matrix_fill(struct matrix *m, double min, double max) {
+	for (usz i = 0; i < m->rows; ++i) 
+		for (usz j = 0; j < m->columns; ++j)
+			m->data[i][j] = frand(min, max);
+}
+
+void matrix_apply(struct matrix *m, const struct fmatrix *fm) {
+	if (m->rows != fm->rows || m->columns != fm->columns) return;
+	for (usz i = 0; i < fm->rows; ++i)
+		for (usz j = 0; j < fm->columns; ++j)
+			m->data[i][j] = (fm->funcs[i][j])(m->data[i][j]);
+}
+
+
+struct tumatrix tumatrix_new(usz size) {
+	double **data = malloc(sizeof (double*) * size);
+	for (usz i = 0; i < size; ++i) 
+		data[i] = malloc(sizeof (double) * (size - i));
+	return (struct tumatrix){.data = data, .size = size};
+}
+
+void tumatrix_free(struct tumatrix m) {
+	for (usz i = 0; i < m.size; ++i)
+		free(m.data[i]);
+	free(m.data);
+}
+
+double tumatrix_at(const struct tumatrix *m, usz row, usz column) {
+	if (row > column) return 0.0;
+	return m->data[row][column - row];
+}
+
+struct tumatrix tumatrix_mul(const struct tumatrix *a, const struct tumatrix *b) {
+	if (a->size != b->size) return (struct tumatrix){0};
+	struct tumatrix c = tumatrix_new(a->size);
+	for (usz i = 0; i < a->size; ++i) {
+		for(usz j = i; j < a->size; ++j) {
+			double psum = 0;
+			// maybe r should go from i to j instead, will see
+			for (usz r = 0; r < a->size; ++r)
+				psum += tumatrix_at(a, i, r) * tumatrix_at(b, r, j);
+			c.data[i][j-i] = psum;
+		}
+	}
+	return c;
+}
+
+// Определитель треугольной матрицы равен произведению элементов её главной диагонали 
+// [https://ru.wikipedia.org/wiki/Треугольная_матрица]
+double tumatrix_det(const struct tumatrix *m) {
+	double prod = 1.0;
+	for (usz i = 0; i < m->size; ++i)
+		prod *= tumatrix_at(m, i, i);
+	return prod;
+}
+
+void tumatrix_fill(struct tumatrix *m, double min, double max) {
+	for (usz i = 0; i < m->size; ++i)
+		for (usz j = 0; j < m->size - i; ++j)
+			m->data[i][j] = frand(min, max);
+}
+
+void tumatrix_print(const struct tumatrix *m) {
+	for (usz i = 0; i < m->size; ++i) {
+		printf("| ");
+		for (usz j = 0; j < m->size; ++j) {
+			printf("%10.3g ", tumatrix_at(m, i, j));
+		}
+		printf("|\n");
+	}
+}
-- 
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