[C] Fuctions compiler error

[Scupham]

I am getting a compiler error which is preventing me from completing my program.

If i can get the one error out it should solve all of the others.

ALL ERRORS ARE IN BOLD SECTION OF CODE

Errors

J:\test\test.c(101) : error C2143: syntax error : missing ';' before 'type'
J:\test\test.c(104) : error C2143: syntax error : missing ';' before 'type'
J:\test\test.c(111) : error C2065: 'sumx' : undeclared identifier
J:\test\test.c(111) : warning C4244: '+=' : conversion from 'double ' to 'int ', possible loss of data
J:\test\test.c(112) : error C2065: 'sumy' : undeclared identifier
J:\test\test.c(112) : warning C4244: '+=' : conversion from 'double ' to 'int ', possible loss of data
J:\test\test.c(113) : error C2065: 'sumxx' : undeclared identifier
J:\test\test.c(113) : warning C4244: '+=' : conversion from 'double ' to 'int ', possible loss of data
J:\test\test.c(114) : error C2065: 'sumxy' : undeclared identifier
J:\test\test.c(114) : warning C4244: '+=' : conversion from 'double ' to 'int ', possible loss of data
J:\test\test.c(116) : error C2065: 'n' : undeclared identifier
J:\test\test.c(120) : error C2065: 'line_parameters_ptr' : undeclared identifier
J:\test\test.c(120) : error C2223: left of '->gradient' must point to struct/union
J:\test\test.c(121) : error C2223: left of '->constant' must point to struct/union
Error executing cl.exe.

test.obj - 10 error(s), 4 warning(s)

Code:

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


struct filenames
{
char measurements_filename[101] ;
char line_parameters_filename[101];
};

struct measurements
{
double x,y;
struct measurements *next;
};

struct line_parameters
{
double gradient, constant;
struct line_parameters *next;
};



int main (void)
{
struct filenames filenames, *filenames_ptr;
struct measurements measurements, *measurement_ptr;
struct line_parameters line_parameters, *line_parameters_ptr;

void get_filenames(struct filenames *);
void read_measurments(struct filenames*, struct measurements *);
void calculate_line_parameters(struct measurements*, struct line_parameters * );
void write_line_parameters(struct filenames, struct line_parameters );

filenames_ptr = &filenames;
measurement_ptr= &measurements;
line_parameters_ptr= &line_parameters;


get_filenames(filenames_ptr);
fprintf(stdout, "%s\n",filenames_ptr->measurements_filename);
fprintf(stdout, "%s\n",filenames_ptr->line_parameters_filename);

read_measurments(filenames_ptr, measurement_ptr);
calculate_line_parameters(measurement_ptr, line_parameters_ptr);
write_line_parameters(filenames, line_parameters);
return(0);
}




void get_filenames(struct filenames *filenames_ptr)
{
fprintf(stdout, "Enter file name:\n");
fscanf(stdin, "%s",filenames_ptr->measurements_filename);

fprintf(stdout, "Enter file name to Save to:\n");
fscanf(stdin, "%s",filenames_ptr->line_parameters_filename);
return;
}




void read_measurments(struct filenames *filenames_ptr, struct measurements *measurement_ptr)
{
char line[101];
char *line_ptr;
int no_values=0;
struct measurements *current_measurements_ptr=measurement_ptr, *new_measurements_ptr;
FILE *input_stream;
input_stream=fopen(filenames_ptr->measurements_filename, "r");

if(input_stream!=NULL)
{
fprintf(stdout, "File found!\n");
fgets(line,sizeof(line), input_stream);

while (((line_ptr=fgets(line,sizeof(line), input_stream))!=NULL) && ((no_values= sscanf(line,"%lf %lf",
&current_measurements_ptr->x,
&current_measurements_ptr->y))==2))
{
current_measurements_ptr -> next=(struct measurements*)malloc(sizeof(struct measurements));
if (measurement_ptr!=NULL)
{
current_measurements_ptr=current_measurements_ptr -> next;
current_measurements_ptr -> next= NULL;
}

}
fclose(input_stream);
return;
}




void calculate_line_parameters(struct measurements *measurement_ptr, struct line_parameters *line_parameters_ptr)
{
struct measurements *measurement_ptr=NULL, *current_measurements_ptr;
double sumx=0, sumy=0, sumxx=0, sumxy=0, n=0;

current_measurements_ptr = new_measurements_ptr ;

while(current_measurements_ptr->next != NULL)
{

sumx += measurement_ptr->x;
sumy += measurement_ptr->y;
sumxx += (measurement_ptr->x) * (measurement_ptr->x);
sumxy += (measurement_ptr->x) * (measurement_ptr->y);

n ++;
current_measurements_ptr = current_measurements_ptr->next;
}

line_parameters_ptr->gradient = ((n * sumxy)-(sumx * sumy))/((n * sumxx)-(sumx * sumx));
line_parameters_ptr->constant = ((sumxy * sumx) - (sumxx * sumy)) / ((sumx * sumx) -(n * sumxx));
fprintf(stdout, "lol WIN!");
return;
}



void write_line_parameters(struct filenames filenames, struct line_parameters line_parameters)
{
FILE *output_stream;
output_stream = fopen(filenames.line_parameters_filename, "w");

fprintf(output_stream, "%lf \n", line_parameters.gradient);
fprintf(output_stream, "%lf \n", line_parameters.constant);

fclose(output_stream);
return;
}

Thanks for your time

[Scupham]

Sorry to have bothered you solved that but now running into more problems, will post in due time

[Scupham]

Ok new issues.

I get the program crashing when i run, it seems to crash when im reading data from the file

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


struct filenames
{
char measurements_filename[101] ;
char line_parameters_filename[101];
};

struct measurements
{
double x,y;
struct measurements *next;
};

struct line_parameters
{
double gradient, constant;
struct line_parameters *next;
};



int main (void)
{
struct filenames filenames, *filenames_ptr;
struct measurements measurements, *measurement_ptr;
struct line_parameters line_parameters, *line_parameters_ptr;

void get_filenames(struct filenames *);
void read_measurments(struct filenames*, struct measurements *);
void calculate_line_parameters(struct measurements*, struct line_parameters * );
void write_line_parameters(struct filenames, struct line_parameters );

filenames_ptr = &filenames;
measurement_ptr= &measurements;
line_parameters_ptr= &line_parameters;


get_filenames(filenames_ptr);
fprintf(stdout, "%s\n",filenames_ptr->measurements_filename);
fprintf(stdout, "%s\n",filenames_ptr->line_parameters_filename);

read_measurments(filenames_ptr, measurement_ptr);
calculate_line_parameters(measurement_ptr, line_parameters_ptr);
write_line_parameters(filenames, line_parameters);
return(0);
}




void get_filenames(struct filenames *filenames_ptr)
{
fprintf(stdout, "Enter file name:\n");
fscanf(stdin, "%s",filenames_ptr->measurements_filename);

fprintf(stdout, "Enter file name to Save to:\n");
fscanf(stdin, "%s",filenames_ptr->line_parameters_filename);
return;
}




void read_measurments(struct filenames *filenames_ptr, struct measurements *measurement_ptr)
{
char line[101];
char *line_ptr;
int no_values=0;
struct measurements *current_measurements_ptr=measurement_ptr;
FILE *input_stream;
input_stream=fopen(filenames_ptr->measurements_filename, "r");

if(input_stream!=NULL)
{
fprintf(stdout, "File found!\n");
fgets(line,sizeof(line), input_stream);

while (((line_ptr=fgets(line,sizeof(line), input_stream))!=NULL) && ((no_values= sscanf(line,"%lf %lf",
&current_measurements_ptr->x,
&current_measurements_ptr->y))==2))
{
current_measurements_ptr -> next=(struct measurements*)malloc(sizeof(struct measurements));
if (measurement_ptr!=NULL)
{
current_measurements_ptr=current_measurements_ptr -> next;
current_measurements_ptr -> next= NULL;
}

}
}
fclose(input_stream);
return;
}




void calculate_line_parameters(struct measurements *measurements, struct line_parameters *line_parameters_ptr)

{
struct measurements *measurement_ptr=NULL, *current_measurements_ptr;

double sumx=0, sumy=0, sumxx=0, sumxy=0, n=0;

current_measurements_ptr = measurements;

while(current_measurements_ptr->next != NULL)
{

sumx += measurement_ptr->x;
sumy += measurement_ptr->y;
sumxx += (measurement_ptr->x) * (measurement_ptr->x);
sumxy += (measurement_patr->x) * (measurement_ptr->y);

n ++;
current_measurements_ptr = current_measurements_ptr->next;
}

line_parameters_ptr->gradient = ((n * sumxy)-(sumx * sumy))/((n * sumxx)-(sumx * sumx));
line_parameters_ptr->constant = ((sumxy * sumx) - (sumxx * sumy)) / ((sumx * sumx) -(n * sumxx));
fprintf(stdout, "lol WIN");
return;
}



void write_line_parameters(struct filenames filenames, struct line_parameters line_parameters)
{
FILE *output_stream;
output_stream = fopen(filenames.line_parameters_filename, "w");

fprintf(output_stream, "%lf \n", line_parameters.gradient);
fprintf(output_stream, "%lf \n", line_parameters.constant);

fclose(output_stream);
return;
}

Any ideas?

[WingedPanther]

Can you narrow down where it crashes a little? For example, do you see the File Found message?

Also, I strongly recommend you use indentation to clarify your code like this:

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


struct filenames
{
  char measurements_filename[101] ;
  char line_parameters_filename[101];
};

struct measurements
{
  double x,y;
  struct measurements *next;
};

struct line_parameters
{
  double gradient, constant;
  struct line_parameters *next;
};



int main (void)
{
  struct filenames filenames, *filenames_ptr;
  struct measurements measurements, *measurement_ptr;
  struct line_parameters line_parameters, *line_parameters_ptr;
  
  void get_filenames(struct filenames *);
  void read_measurments(struct filenames*, struct measurements *);
  void calculate_line_parameters(struct measurements*, struct line_parameters * );
  void write_line_parameters(struct filenames, struct line_parameters );
  
  filenames_ptr = &filenames;
  measurement_ptr= &measurements;
  line_parameters_ptr= &line_parameters;
  
  
  get_filenames(filenames_ptr);
  fprintf(stdout, "%s\n",filenames_ptr->measurements_filename);
  fprintf(stdout, "%s\n",filenames_ptr->line_parameters_filename);
  
  read_measurments(filenames_ptr, measurement_ptr);
  calculate_line_parameters(measurement_ptr, line_parameters_ptr);
  write_line_parameters(filenames, line_parameters);
  return(0);
}




void get_filenames(struct filenames *filenames_ptr)
{
  fprintf(stdout, "Enter file name:\n");
  fscanf(stdin, "%s",filenames_ptr->measurements_filename);
  
  fprintf(stdout, "Enter file name to Save to:\n");
  fscanf(stdin, "%s",filenames_ptr->line_parameters_filename);
  return;
}




void read_measurments(struct filenames *filenames_ptr, struct measurements *measurement_ptr)
{
  char line[101];
  char *line_ptr;
  int no_values=0;
  struct measurements *current_measurements_ptr=measurement_ptr;
  FILE *input_stream;
  input_stream=fopen(filenames_ptr->measurements_filename, "r");
  
  if(input_stream!=NULL)
  {
    fprintf(stdout, "File found!\n");
    fgets(line,sizeof(line), input_stream);
    
    while (((line_ptr=fgets(line,sizeof(line), input_stream))!=NULL) && ((no_values= sscanf(line,"%lf %lf",
    &current_measurements_ptr->x,
    &current_measurements_ptr->y))==2))
    {
      current_measurements_ptr -> next=(struct measurements*)malloc(sizeof(struct measurements));
      if (measurement_ptr!=NULL)
      {
        current_measurements_ptr=current_measurements_ptr -> next;
        current_measurements_ptr -> next= NULL;
      }
    
    }
  }
  fclose(input_stream);
  return;
}




void calculate_line_parameters(struct measurements *measurements, struct line_parameters *line_parameters_ptr)

{
  struct measurements *measurement_ptr=NULL, *current_measurements_ptr;
  
  double sumx=0, sumy=0, sumxx=0, sumxy=0, n=0;
  
  current_measurements_ptr = measurements;
  
  while(current_measurements_ptr->next != NULL)
  {
  
    sumx += measurement_ptr->x;
    sumy += measurement_ptr->y;
    sumxx += (measurement_ptr->x) * (measurement_ptr->x);
    sumxy += (measurement_patr->x) * (measurement_ptr->y);
    
    n ++;
    current_measurements_ptr = current_measurements_ptr->next;
  }
  
  line_parameters_ptr->gradient = ((n * sumxy)-(sumx * sumy))/((n * sumxx)-(sumx * sumx));
  line_parameters_ptr->constant = ((sumxy * sumx) - (sumxx * sumy)) / ((sumx * sumx) -(n * sumxx));
  fprintf(stdout, "lol WIN");
  return;
}



void write_line_parameters(struct filenames filenames, struct line_parameters line_parameters)
{
  FILE *output_stream;
  output_stream = fopen(filenames.line_parameters_filename, "w");
  
  fprintf(output_stream, "%lf \n", line_parameters.gradient);
  fprintf(output_stream, "%lf \n", line_parameters.constant);
  
  fclose(output_stream);
  return;
}