Re: Undefined reference to `gsl_spmatrix_uchar_norm1'

[Patrick Alken]

Hello,

  Unsigned versions of this function were excluded (uchar, uint, 
ushort), because there is the possibility of adding two large uchar 
values together during the 1-norm calculation and ending up with a 
smaller value due to it wrapping back to 0. This didn't make much sense 
to me when I wrote the function, so I excluded the unsigned versions.

Do you think it makes sense to have a uchar_norm1 function?

Patrick

On 6/25/21 11:45 AM, Håkon Hægland wrote:
> I am on Ubuntu 21.04, using GSL 2.7. Here is my test program norm.c :
>
>
> #include <stdio.h>
> #include <gsl/gsl_spmatrix.h>
> int
> main()
> {
>      gsl_spmatrix_uchar *A = gsl_spmatrix_uchar_alloc(2, 2);
>
>      gsl_spmatrix_uchar_set(A, 0, 0, 1);
>      gsl_spmatrix_uchar_set(A, 0, 1, 2);
>      gsl_spmatrix_uchar_set(A, 1, 0, 3);
>      gsl_spmatrix_uchar_set(A, 1, 1, 4);
>
>      double norm = gsl_spmatrix_uchar_norm1(A);
>      printf("norm = %g\n", norm);
>      gsl_spmatrix_uchar_free(A);
>
>      return 0;
> }
>
> When I compile this I get an error message from the linker:
>
> $ gcc -Wall -I/opt/gsl/gsl-2.7/include -c norm.c
> $ gcc -L/opt/gsl/gsl-2.7/lib -o norm norm.o -lgsl -lgslcblas -lm
> /bin/ld: norm.o: in function `main':
> norm.c:(.text+0x93): undefined reference to `gsl_spmatrix_uchar_norm1'
> collect2: error: ld returned 1 exit status
>
> Best regards,
> Håkon Hægland