GNU Scientific Library Reference Manual - Third Edition (v1.12)by M. Galassi, J. Davies, J. Theiler, B. Gough, G. Jungman, P. Alken, M. Booth, F. Rossi Paperback (6"x9"), 592 pages, 60 figures ISBN 0954612078 RRP £24.95 ($39.95) |

### 8.4.4 Reading and writing matrices

The library provides functions for reading and writing matrices to a file as binary data or formatted text.

__Function:__int**gsl_matrix_fwrite***(FILE **`stream`, const gsl_matrix *`m`)- This function writes the elements of the matrix
`m`to the stream`stream`in binary format. The return value is 0 for success and`GSL_EFAILED`

if there was a problem writing to the file. Since the data is written in the native binary format it may not be portable between different architectures.

__Function:__int**gsl_matrix_fread***(FILE **`stream`, gsl_matrix *`m`)- This function reads into the matrix
`m`from the open stream`stream`in binary format. The matrix`m`must be preallocated with the correct dimensions since the function uses the size of`m`to determine how many bytes to read. The return value is 0 for success and`GSL_EFAILED`

if there was a problem reading from the file. The data is assumed to have been written in the native binary format on the same architecture.

__Function:__int**gsl_matrix_fprintf***(FILE **`stream`, const gsl_matrix *`m`, const char *`format`)- This function writes the elements of the matrix
`m`line-by-line to the stream`stream`using the format specifier`format`, which should be one of the`%g`

,`%e`

or`%f`

formats for floating point numbers and`%d`

for integers. The function returns 0 for success and`GSL_EFAILED`

if there was a problem writing to the file.

__Function:__int**gsl_matrix_fscanf***(FILE **`stream`, gsl_matrix *`m`)- This function reads formatted data from the stream
`stream`into the matrix`m`. The matrix`m`must be preallocated with the correct dimensions since the function uses the size of`m`to determine how many numbers to read. The function returns 0 for success and`GSL_EFAILED`

if there was a problem reading from the file.

ISBN 0954612078 | GNU Scientific Library Reference Manual - Third Edition (v1.12) | See the print edition |