Files
Lina/lina.c
T
2022-01-14 03:36:59 +01:00

100 lines
2.4 KiB
C

#include <stddef.h>
#include <assert.h>
#include <stdlib.h>
#include <string.h>
#include "lina.h"
#define check assert
void lina_dot(double *A, double *B, double *C, int m, int n, int l){
assert(m > 0 && n > 0 && l > 0);
assert(A != NULL && B != NULL && C != NULL);
assert(A != C && B != C);
// Iteration over A's rows
for(int i = 0; i < m; i++)
{
// Iteration over B's columns
for(int k = 0; k < l; k++)
{
double pos = 0;
// Iteration over the single B column
// for executing the product of sum
for(int j=0; j < n; j++)
pos += A[i*n + j] * B[j*l + k];
// The usage of a support variable 'pos'
// is for safety purpose (non-zero C matrix)
C[i*l + k] = pos;
}
}
}
void lina_add(double *A, double *B, double *C, int m, int n){
assert(m > 0 && n > 0);
assert(A != NULL && B != NULL && C != NULL);
for(int i = 0; i < m; i++)
for(int j = 0; j < n; j++)
C[i*n + j] = A[i*n + j] + B[i*n + j];
}
void lina_scale(double *A, double *B, double k, int m, int n){
assert(m > 0 && n > 0);
assert(A != NULL && B != NULL);
for(int i = 0; i < m; i++)
for(int j = 0; j < n; j++)
B[i*n + j] = k * A[i*n + j];
}
void lina_transpose(double *A, double *B, int m, int n)
{
assert(m > 0 && n > 0);
assert(A != NULL && B != NULL);
if(m == 1 || n == 1)
{
memcpy(B, A, sizeof(A[0]) * m * n);
return;
}
if(m == n)
{
for(int i = 0; i < n; i += 1)
for(int j = 0; j < i+1; j += 1)
{
double temp = A[i*n + j];
B[i*n + j] = A[j*n + i];
B[j*n + i] = temp;
}
}
else
{
B[0] = A[0];
B[m*n-1] = A[m*n-1];
double item = A[1];
int next = m;
while(next != 1)
{
double temp = A[next];
B[next] = item;
item = temp;
next = (next % n) * m + (next / n);
}
B[1] = item;
}
}