length of array filled with pointers?

[Thomas Deschepper]

I'm writing a little matrix multiplication program, and for the moment, I
have to check if two matrices have the same dimensions. A matrix in my
program is an array of pointers. How can I check if two of those matrices
have the same dimensions, e.g.: 3*3?

Thank you, Thomas
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[Kenneth Brody]

I'm writing a little matrix multiplication program, and for the moment, I
have to check if two matrices have the same dimensions. A matrix in my
program is an array of pointers. How can I check if two of those matrices
have the same dimensions, e.g.: 3*3?

By making a struct which includes a pointer to this matrix, along with a
height and width. Then, compare the height and width.

 

[Malcolm]

I'm writing a little matrix multiplication program, and for the moment, I
have to check if two matrices have the same dimensions. A matrix in my
program is an array of pointers. How can I check if two of those matrices
have the same dimensions, e.g.: 3*3?

A C pointer is normally implemented as just a bare address. There is
therefore no way of knowing what object a pointer points to, short of
keeping track of this information in the program (the C type system does a
lot of that for you).

What you need to do is declare

typedef struct
{
int width;
int height;
double *values;
} MATRIX;

Then the function is passed two MATRIX *s, and simply checks the width and
height fields.

 

[Thomas Deschepper]

I'm writing a little matrix multiplication program, and for the moment, I
have to check if two matrices have the same dimensions. A matrix in my
program is an array of pointers. How can I check if two of those matrices
have the same dimensions, e.g.: 3*3?

Thank you, Thomas

Thx for the quick replies

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