Thread: Transpose Matrix

Im busy trying to transpose my array but the code doesnt seem to be working...Can someone help me out please?

Code:

#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <math.h>


#define N 3



int find_inner_product (int *a,int *b,int size)
	
{int inner_product=0,i=0;
	for (i=0;i<size;i++)
		
		{inner_product=inner_product+ *(a+i)*(*(b+i));}
		
	return inner_product;} /*function to do the inner product*/

int matrix_transpose(int a[][N],int size)
	
{int i=0,j=0,temp[N][N],transpose_matrix[N][N];
	for	( i = 0; i<N; i++ ) 
	{for( j = 0; j<N; j++ )
		
	{		a[i][j]=temp[i][j];
		temp[i][j]=transpose_matrix[j][i];
		}
	}
}

int main(void)
{
	int matrix1[N][N],matrix2[N][N],i=0,j=0,inner_product=0,transpose_matrix[N][N];
	
	
	printf("Please enter the values of the 3x3 Matrix: ");
	
	for	( i = 0; i < N; i++ ) 
		{for( j = 0; j< N; j++ )
		
		{scanf("%d", &matrix1[i][j]);}
			
		} /*this for loop goes through every number and stores it in the first matrix*/
		printf("\nPlease enter the values of the second 3x3 Matrix: ");
	
	for	( i = 0; i < N; i++ ) 
	{for( j = 0; j< N; j++ )
		
		{scanf("%d", &matrix2[i][j]);}
		} /*this for loop goes through every number and stores it in the second matrix*/

	
	inner_product=find_inner_product(matrix1,matrix2,N); /*calling the function to do the first row dot product*/
	printf("\nThe inner product between the top two rows is %d",inner_product);
	
	for	( i = 0; i < N; i++ ) 
	{for( j = 0; j< N; j++ )
	transpose_matrix[i][j]=matrix_transpose( matrix1[N][N],N);
	}
	
	for	( i = 0; i < N; i++ ) 
	{for( j = 0; j< N; j++ )
		printf("\n%d", transpose_matrix[i][j]);
}
}

The problem is with the transpose function,

Code:

int matrix_transpose(int a[N][N],int size)
	
{int i=0,j=0,temp[N][N],transpose_matrix[N][N];
	for	( i = 0; i<N; i++ ) 
	{for( j = 0; j<N; j++ )
		
	{		a[i][j]=temp[i][j];
		temp[i][j]=transpose_matrix[j][i];
		}
	}

Whats the problem?

Ive refined it a tiny bit but i still cant seem to find the problem. Again, the transpose doesnt work!

Code:

#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <math.h>


#define N 3



int find_inner_product (int *a,int *b,int size)
	
{int inner_product=0,i=0;
	for (i=0;i<size;i++)
		
		{inner_product=inner_product+ *(a+i)*(*(b+i));}
		
	return inner_product;} /*function to do the inner product*/

int matrix_transpose(int a[N][N],int size)
	
{int i=0,j=0,temp[N][N],transpose_matrix[N][N];
	for	( i = 0; i<N; i++ ) 
	{for( j = 0; j<N; j++ )
		
	{		a[i][j]=temp[i][j];
		temp[i][j]=transpose_matrix[j][i];
		}
	}
}

int main(void)
{
	int matrix1[N][N],matrix2[N][N],i=0,j=0,inner_product=0,transpose_matrix[N][N];
	
	
	printf("Please enter the values of the 3x3 Matrix: ");
	
	for	( i = 0; i < N; i++ ) 
		{for( j = 0; j< N; j++ )
		
		{scanf("%d", &matrix1[i][j]);}
			
		} /*this for loop goes through every number and stores it in the first matrix*/
		printf("\nPlease enter the values of the second 3x3 Matrix: ");
	
	for	( i = 0; i < N; i++ ) 
	{for( j = 0; j< N; j++ )
		
		{scanf("%d", &matrix2[i][j]);}
		} /*this for loop goes through every number and stores it in the second matrix*/

	
	inner_product=find_inner_product(matrix1,matrix2,N); /*calling the function to do the first row dot product*/
	printf("\nThe inner product between the top two rows is %d",inner_product);
	
	matrix_transpose(matrix2,N);

Code:

int matrix_transpose(int a[N][N],int size)
	
{int i=0,j=0,temp[N][N],transpose_matrix[N][N];
	for	( i = 0; i<N; i++ ) 
	{for( j = 0; j<N; j++ )
		
	{		a[i][j]=temp[i][j];
		temp[i][j]=transpose_matrix[j][i];
		}
	}
}

1) You need to pass in the array as a pointer, not as an array definition.
2) using a[N] does not give you access to N inside the function.
3) transposing (swapping) values requrires 3 steps not 2... save first value, move second value to first, copy saved value to second.
4) When calling the function you correctly passed in the size, but totally ignored it within the function.
5) your temp variable does not need to be an array
6) the function should not call itself... let the loops do their work.

What should my three lines of code look like to save tranpose it? The three steps?
All i have at the moment is:

Code:

int matrix_transpose(int a[N][N],int size)
	
{int i=0,j=0,temp=0,transpose_matrix[N][N];
	for	( i = 0; i<N; i++ ) 
	{for( j = 0; j<N; j++ )
		
	{	temp=a[i][j];
		temp=transpose_matrix[i][j];
		}
	}
}

So you've got a red cup full of water, a blue cup full of tea, and an empty green cup. How would you get the red cup full of tea and the blue cup full of water?

Also: you are currently transposing your matrix twice (once for (i,j) and once for (j,i)), hence when you do get your swap working you won't get the answer you want, since if you swap everything twice it ends up exactly where it was at the beginning. Once you have put the first row into the first column, then you shouldn't mess with the first column when you do the next row.

Originally Posted by Micki-Zee

What should my three lines of code look like to save tranpose it? The three steps?

Code:

temp = a;        // save first value
a = b;          // copy transposed value
b = temp;       // copy saved value