Ytukyg

I have this weird problem where sometimes this function not always work, and only works if it's declared in the same headers where it is called... It's a really strange thing because the compiler it seems even ignores if the files containing the function are included or not...

double mapRange(double value, double r1, double r2, double n1, double n2)

{

    double res = n1+(value-r1)*((n2-n1)/(r2-r1));

    printf("dividingby: %f", res);putchar('n');

    return res;

}

as you can see when it prints the value it is correct however when I print the returned value from another function like main I get garbage numbers...
Worst thing is I tested it on a file by itself and it worked flawlessly, I know this seems like an error from my part but I really can't find an explanation for this... Has someone encountered something like that? Is my compiler broken? Is there any limits in C that I'm not aware of? I know too that I don't have much more code to offer than this which kind of makes it difficult for a diagnosis but it's from a rather not-so-small project for uni...

EDIT 1:
OK so

// main.c

 #ifndef UTIL_H

    #define UTIL_H

    #include "util.h"

    #endif /*UTIL_H*/



int main(int argc, char *argv) {

    Matrix* volcan = readVolcano("test.txt");

    double t;

    mapRange(7.0, 1.0, 9.0, 0.0, 1.0,&t);

    printf("%fn..n", t);

    mat_printinfo(volcan);

    mat_printmat(volcan, NULL);

    weighted_volcano(volcan, NULL, NULL, NULL);

    mat_free(volcan);

    return 0;

}

// util.c

#include "util.h"





/*

    Retorna una transformacion de value que esta entre r1 y r2 a un valor que esta

    entre n1 y n2, con tal que tenga la misma relacion con el rango [n1, n2] como

    value tenga con el rango [r1, r2]

*/





double mapRange(double value, double r1, double r2, double n1, double n2, double* result)

{

    double res = n1+(value-r1)*((n2-n1)/(r2-r1));

    printf("dividingby: %f", res);putchar('n');

    if(result!=NULL)

    *result = res;

    return res;

}

I'm absolutely sure there's not a duplicate in definition, I've also rebuilt the project many times...

D:CodeCvolcancc1.exe    [Warning] command line option '-std=c++11' is valid for C++/ObjC++ but not for C

D:CodeCvolcanmain.c In function 'main':

52  19  D:CodeCvolcanmain.c [Warning] initialization makes pointer from integer without a cast

D:CodeCvolcanmain.c In function 'open_volcano':

91  7   D:CodeCvolcanmain.c [Warning] assignment makes pointer from integer without a cast

D:CodeCvolcanmain.c In function 'test_volcano':

119 13  D:CodeCvolcanmain.c [Warning] assignment makes pointer from integer without a cast

D:CodeCvolcancc1.exe    [Warning] command line option '-std=c++11' is valid for C++/ObjC++ but not for C

D:CodeCvolcanvolcantobmp.c  In function 'weighted_volcano':

38  6   D:CodeCvolcanvolcantobmp.c  [Warning] assignment makes pointer from integer without a cast

40  6   D:CodeCvolcanvolcantobmp.c  [Warning] assignment makes pointer from integer without a cast

D:CodeCvolcancc1.exe    [Warning] command line option '-std=c++11' is valid for C++/ObjC++ but not for C

the output of the IDE

EDIT 2:
So it seems the problem was here

// util.h

#include "headers.h"

it was empty...

Based on your description, it is most likely that there is another "mapRange" function somewhere in your "code base".

Just to isolate the problem, I recommend renaming your "mapRange" function to something unique like appending today's date (mapRange_20181127) leaving mapRange call in main(). If your "code base" contains another function with name "mapRange", you will not face any error as linker would find the "other" mapRange.

If this is the case, choosing another meaningful name would solve your issue.

Hope this helps!

Update:
I guess while I'm typing, you posted more details and you got your answer :).

@SteveSummit gave me the solution it needed a prototype declaration for the function in util.h