fatal error

hello!

i cant find the problem, please help me :)
the errors:POLINK: error:

Unresolved external symbol '_printA'.
POLINK: error: Unresolved external symbol '_printO'.
POLINK: fatal error: 2 unresolved external(s).

Code:

---

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

void scaling(double* P[],double B[], int i,  int j,int order);

void PrintA(double A[30][30], int m,int n);

void PrintO(double* O[30], double B[30],int m,int n);


int main()
{
    double A[30][30];
    double B[30];
    double* O[30];
    int i,j,m,n,order;

printf("enter the number of rows and columns: \n");
scanf("%d%d",&i,&j);
printf("enter %d*%d matrix\n:",i,j);

for (m=0 ; m<i ; m++)
    for(n=0 ; n<j ; n++)
        scanf("%lf",&(A[m][n]));

printf("enter %d vector: \n",i);

for (m=0 ; m<i ; m++)
scanf("%lf",&(B[m]));
 
for(order=0;order<i;order++);
{
        scaling(O,B,i,j,order);
        printA(A,i,j);
        printO(O,B,i,j);
}
        return 0;
}

void scaling(double* P[],double B[], int i,  int j,int order)
{
int m,n,maxrow;
double max[30], maxi=0,temp2;
double* temp;
    for (m=order;m<i;m++)
        for(n=order;n<j && fabs(P[m][n])>max[m];n++)
                      max[m]=fabs(P[m][n]);
for (m=order;m<i;m++)
        if ((fabs(P[m][order])/max[m])>maxi)
                {
                maxi=(fabs(P[m][order]/max[m]));
                maxrow=m;
                }
if(maxrow!=order)
        {
            temp=P[maxrow];
            P[maxrow]=P[order];
            P[order]=temp;

            temp2=B[maxrow];
            B[maxrow]=B[order];
            B[order]=temp2;

        }

}

void PrintA(double A[30][30], int m,int n)
{
        int i,j;

        printf("original coefficients matrix:\n");
        for(i=0;i<m;i++)
        {
                for(j=0;j<n;j++)
                        printf("%.2lf ",A[i][j]);

                printf("\n");
        }
        printf("\n");
}

void PrintO(double* O[30], double B[30], int m,int n)
{
        int i,j;

        printf("current matrix:\n");
        for(i=0;i<m;i++)
        {
                for(j=0;j<n;j++)
                        printf("%.2lf ",O[i][j]);
                printf("| %.2lf",B[i]);
                printf("\n");
        }
        printf("\n");
}

---

thank!

printA is different from PrintA, and similarly printO is different from PrintO.

hello' thank you for the answer!
i have a run time error now....
it stops when it spouse to print marix O.

Code:

---


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

void scaling(double* P[],double B[], int i,  int j,int order);

void printA(double A[30][30], int m,int n);

void printO(double* O[30], double B[30],int m,int n);


int main()
{
    double A[30][30];
    double B[30];
    double* O[30];
    int i,j,m,n,order;

printf("enter the number of rows and columns: \n");
scanf("%d%d",&i,&j);
printf("enter %d*%d matrix\n:",i,j);

for (m=0 ; m<i ; m++)
    for(n=0 ; n<j ; n++)
        scanf("%lf",&(A[m][n]));

printf("enter %d vector: \n",i);

for (m=0 ; m<i ; m++)
scanf("%lf",&(B[m]));
 
for(order=0;order<i;order++);
{
        scaling(O,B,i,j,order);
        printA(A,i,j);
        printO(O,B,i,j);
}
        return 0;
}

void scaling(double* P[],double B[], int i,  int j,int order)
{
int m,n,maxrow;
double max[30], maxi=0,temp2;
double* temp;
    for (m=order;m<i;m++)
        for(n=order;n<j && fabs(P[m][n])>max[m];n++)
                      max[m]=fabs(P[m][n]);
for (m=order;m<i;m++)
        if ((fabs(P[m][order])/max[m])>maxi)
                {
                maxi=(fabs(P[m][order]/max[m]));
                maxrow=m;
                }
if(maxrow!=order)
        {
            temp=P[maxrow];
            P[maxrow]=P[order];
            P[order]=temp;

            temp2=B[maxrow];
            B[maxrow]=B[order];
            B[order]=temp2;

        }

}

void printA(double A[30][30], int m,int n)
{
        int i,j;

        printf("original coefficients matrix:\n");
        for(i=0;i<m;i++)
        {
                for(j=0;j<n;j++)
                        printf("%.2lf ",A[i][j]);

                printf("\n");
        }
        printf("\n");
}

void printO(double* O[30], double B[30], int m,int n)
{
        int i,j;

        printf("current matrix:\n");
        for(i=0;i<m;i++)
        {
                for(j=0;j<n;j++)
                        printf("%f ",O[i][j]);
                printf("| %f",B[i]);
                printf("\n");
        }
        printf("\n");
}

---

hi!

i have a run time error, i tried to fix it but i failed.... :(

please help me if you figure it out.

i think its about the scaling func.

Code:

---


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

void scaling(double* P[],double B[], int i,  int j,int order);

void printA(double A[30][30], int m,int n);

void printO(double* O[30], double B[30],int m,int n);

void calc(double* O[30], double B[30], int m,int n,int order);

int main()
{
    double A[30][30];
    double B[30];
    double* O[30];
    int i,j,m,n,order;

printf("enter the number of rows and columns: \n");
scanf("%d%d",&i,&j);
printf("enter %d*%d matrix\n:",i,j);

for (m=0 ; m<i ; m++)
    for(n=0 ; n<j ; n++)
        scanf("%lf",&(A[m][n]));

printf("enter %d vector: \n",i);

for (m=0 ; m<i ; m++)
scanf("%lf",&(B[m]));
 
for(order=0;order<i;order++);
{
        scaling(O,B,i,j,order);
        calc(O,B,i,j,order);
        printA(A,i,j);
        printO(O,B,i,j);
}
        return 0;
}

void scaling(double* P[],double B[], int i,  int j,int order)
{
int m,n,maxrow;
double max[30], maxi=0,temp2;
double* temp;
        for(m=order;m<i;m++)
                max[m]=0;

    for (m=order;m<i;m++)
        for(n=order;n<j;n++)
                      if (max[m]< fabs(P[m][n]))
 max[m]=fabs(P[m][n]);
for (m=order;m<i;m++)
        if ((fabs(P[m][order])/max[m])>maxi)
                {
                maxi=(fabs(P[m][order]/max[m]));
                maxrow=m;
                }
if(maxrow!=order)
        {
            temp=P[maxrow];
            P[maxrow]=P[order];
            P[order]=temp;

            temp2=B[maxrow];
            B[maxrow]=B[order];
            B[order]=temp2;

        }

}

void printA(double A[30][30], int m,int n)
{
        int i,j;

        printf("original coefficients matrix:\n");
        for(i=0;i<m;i++)
        {
                for(j=0;j<n;j++)
                        printf("%.2lf ",A[i][j]);

                printf("\n");
        }
        printf("\n");
}

void printO(double* O[30], double B[30], int m,int n)
{
        int i,j;

        printf("current matrix:\n");
        for(i=0;i<m;i++)
        {
                for(j=0;j<n;j++)
                        printf("%f ",O[i][j]);
                printf("| %f",B[i]);
                printf("\n");
        }
        printf("\n");
}

void calc(double* O[30], double B[30], int m,int n,int order)
{
        int i,j;

for (i=order;i<m-1;i++);
{
                for (j=order;j<n;j++);
                O[i+1][j]=O[i+1][j]-O[order][j]*O[order+1][order]/O[order][order];
}
}

---

Calling variables "O" is a very BAD THING, because it makes them look so similar to the digit "0".

When running your program with 2x2 matrix with the values 1, 2, 3, 4 and 1, 2 in the vector, it crashes with a NULL memory access here (at what seems to be O[1][1] ??):

Code:

---

    O[i+1][j]=O[i+1][j]-O[order][j]*O[order+1][order]/O[order][order];

---

I'm not entirely surprised at that, since O is an array of pointer, and you do not call malloc [or similar functions] in your code.

--
Mats

Agreed.

- Single letter identifiers.
- poorly indented code.
Neither are good when it comes to getting others to look at your code.

hi,
I'm doing this work with Miri.
We fixed the 0-O mistake. It makes the run time error come a bit later...
Anybody can figure out why it won't work?

Thank you.

Quote:

---

Originally Posted by Livnat

hi,
I'm doing this work with Miri.
We fixed the 0-O mistake. It makes the run time error come a bit later...
Anybody can figure out why it won't work?

Thank you.

---

Given that we have no idea what the new code looks like, how do you think we can know what is going wrong?

--
Mats

I t looks pretty much the same. We changed the O's and the 0's to P's. Maybe we should change all the names to something more meaningful like you suggested . In the meantime, here's the code:

Code:

---


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

void scaling(double* P[],double B[], int i,  int j,int order);

void printA(double A[30][30], int m,int n);

void printP(double* P[30], double B[30],int m,int n);

void calc(double* P[30], double B[30], int m,int n,int order);

int main()
{
  double A[30][30];
  double B[30];
  double* P[30];
  int i,j,m,n,order;

printf("enter the number of rows and columns: \n");
scanf("&#37;d%d",&i,&j);
printf("enter %d*%d matrix\n:",i,j);

for (m=0 ; m<i ; m++)
  for(n=0 ; n<j ; n++)
      scanf("%lf",&(A[m][n]));

printf("enter %d vector: \n",i);

for (m=0 ; m<i ; m++)
scanf("%lf",&(B[m]));

for(order=0;order<i;order++);
{
      scaling(P,B,i,j,order);
      calc(P,B,i,j,order);
      printA(A,i,j);
      printP(P,B,i,j);
}
      return 0;
}

void scaling(double* P[],double B[], int i,  int j,int order)
{
int m,n,maxrow;
double max[30], maxi=0,temp2;
double* temp;
      for(m=order;m<i;m++)
              max[m]=0;

  for (m=order;m<i;m++)
      for(n=order;n<j;n++)
                    if (max[m]< fabs(P[m][n]))
 max[m]=fabs(P[m][n]);
for (m=order;m<i;m++)
      if ((fabs(P[m][order])/max[m])>maxi)
              {
              maxi=(fabs(P[m][order]/max[m]));
              maxrow=m;
              }
if(maxrow!=order)
      {
          temp=P[maxrow];
          P[maxrow]=P[order];
          P[order]=temp;

          temp2=B[maxrow];
          B[maxrow]=B[order];
          B[order]=temp2;

      }

}

void printA(double A[30][30], int m,int n)
{
      int i,j;

      printf("original coefficients matrix:\n");
      for(i=0;i<m;i++)
      {
              for(j=0;j<n;j++)
                      printf("%.2lf ",A[i][j]);

              printf("\n");
      }
      printf("\n");
}

void printP(double* P[30], double B[30], int m,int n)
{
      int i,j;

      printf("current matrix:\n");
      for(i=0;i<m;i++)
      {
              for(j=0;j<n;j++)
                      printf("%f ",P[i][j]);
              printf("| %f",B[i]);
              printf("\n");
      }
      printf("\n");
}

void calc(double* P[30], double B[30], int m,int n,int order)
{
      int i,j;

for (i=order;i<m-1;i++);
{
              for (j=order;j<n;j++);
              P[i+1][j]=(P[i+1][j]-P[order][j]*P[order+1][order]/P[order][order]);
}
}

---

Thanks...

So what is your P array pointing to? You only fixed the first of my two suggestions.

--
Mats

hi thank you!

to simplify the problem, here is the problematic loop:

Code:

---


void diagonal(double* P[30], double B[30], int m,int n,int order)//diagonal b!!
{
      int i,j,k;
printf("im alive\n");
for (i=order;i<m;i++)
              for (j=0;j<order;j++)
                for (k=1;k<m+1-order;k++)
              P[i+k][j]=(P[i+k][j]-P[order][j]*P[order+k][order]/P[order][order]);
printf("im alive\n");
}

---

and this is the intire code:

Code:

---

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

void scaling(double* P[],double B[], int i,  int j,int order);

void printA(double A[30][30], int m,int n);

void printP(double* P[30], double B[30],int m,int n);

void diagonal(double* P[30], double B[30], int m,int n,int order);

void calc(double* P[30], double B[30], int m,int n);

int main()
{
  double A[30][30];
  double B[30];
  double* P[30];
  int i,j,m,n,order;

printf("enter the order of the matrix: \n");
scanf("%d",&i);
printf("enter %d*%d matrix:\n",i,i);
j=i;
for (m=0 ; m<i ; m++)
  for(n=0 ; n<j ; n++)
      scanf("%lf",&(A[m][n]));

printf("enter %d vector: \n",i);

for (m=0 ; m<i ; m++)
scanf("%lf",&(B[m]));

for (m=0;m<i;m++)
                P[m]=A[m];
printP(P, B, m, n);

for(order=0;order<i;order++)
{
      scaling(P,B,i,j,order);
printA(A,i,j);
      printP(P,B,i,j);
      diagonal(P,B,i,j,order);
      printA(A,i,j);
      printP(P,B,i,j);
}
calc(P, B,  m, n);
      return 0;
}

void scaling(double* P[],double B[], int i,  int j,int order)
{
int m,n,maxrow;
double max[30], maxi=0,temp2;
double* temp;
      for(m=order;m<i;m++)
              max[m]=0;

  for(m=order;m<i;m++)
              printf("%f",max[m]);

  for (m=order;m<i;m++)
      for(n=order;n<j;n++)
                    if (max[m]< fabs(P[m][n]))
{
 max[m]=fabs(P[m][n]);
printf("max%d=%f\n",m,max[m]);
}
for (m=order;m<i;m++)
      if ((fabs(P[m][order])/max[m])>maxi)
              {
              maxi=(fabs(P[m][order]/max[m]));
              maxrow=m;
              }
if(maxrow!=order)
      {
          temp=P[maxrow];
          P[maxrow]=P[order];
          P[order]=temp;

          temp2=B[maxrow];
          B[maxrow]=B[order];
          B[order]=temp2;

      }

}

void printA(double A[30][30], int m,int n)
{
      int i,j;

      printf("original coefficients matrix:\n");
      for(i=0;i<m;i++)
      {
              for(j=0;j<n;j++)
                      printf("%.2lf ",A[i][j]);

              printf("\n");
      }
      printf("\n");
}

void printP(double* P[30], double B[30], int m,int n)
{
      int i,j;

      printf("current matrix:\n");
      for(i=0;i<m;i++)
      {
              for(j=0;j<n;j++)
                      printf("%f ",P[i][j]);
              printf("| %f",B[i]);
              printf("\n");
      }
      printf("\n");
}

void diagonal(double* P[30], double B[30], int m,int n,int order)//diagonal b!!
{
      int i,j,k;
printf("im alive\n");
for (i=order;i<m;i++)
              for (j=0;j<order;j++)
                for (k=1;k<m+1-order;k++)
              P[i+k][j]=(P[i+k][j]-P[order][j]*P[order+k][order]/P[order][order]);
printf("im alive\n");
}

void calc(double* P[30], double B[30], int m,int n)
{
int i,j;
double x[30],y[30];
for (i=0;i<m;i++)
y[i]=B[i];
for (i=0;i<m;i++)
x[i]=0;
for (i=m;i>0;i--)
{
for (j=m;j>i;j--)
y[i]-=P[i][j]*x[j];
x[i]=y[i]/P[i][i];
printf("x[%d]=%f",i,x[i]);
}
}

---

we still have a run time error....

thanks,
miri & livnat :)

when i = m-1
k = m-order
i+k = 2m-order-1

when order = 0 you are accessing index 2m-1 which could be way out of bounds

I suppose other combinations of indexes are also bloated...

thank you Vart.
we did some adjestmants, here is the new loop...

Code:

---

void diagonal(double* P[30], double B[30], int m,int n,int order)//diagonal b!!
{
      int j,k;
printf("im alive\n");
        for (k=1;k<m+1-order;k++)
      for (j=0;j<m;j++)
        P[k+order][j+order]=(P[k+order][j+order]-P[order][j+order]*P[order+k][order]/P[order][order]);
printf("im not alive\n");
}

---

this is the fixed loop:

Code:

---

void diagonal(double* P[30],double B[30],int m,int order)//diagonal b!!
{
      int j,k;
        for (k=1;k<m-order;k++)
      for (j=0;j<m;j++)
        P[k+order][j+order]=(P[k+order][j+order]-P[order][j+order]*P[order+k][order]/P[order][order]);

}

---

the hole code still doesn't work peoperly,,,
we'll be back ....

j+order could be bigger than m
in your inner loop - add the index checks with assert or printf

Code:

---

if(k+order <0 || k+order >= m) printf("k+order(&#37;d) error", k+order);
if(j+order<0 || j+order>= m) printf("j+order(%d) error", j+order);
if(order <0 || order >= m) printf("order(%d) error", order);

---

for each index you are using...

thanks for the help

enjoy:

Code:

---

int m,n,maxrow;
double max[30], maxi=0,temp2;
double* temp;
      for(m=order;m<i;m++)
              max[m]=0;

           
  for (m=order;m<i;m++)
      for(n=order;n<j;n++)
                    if (max[m]< fabs(P[m][n]))
                                                max[m]=fabs(P[m][n]);

for (m=order;m<i;m++)
      if ((fabs(P[m][order])/max[m])>maxi)
              {
              maxi=(fabs(P[m][order]/max[m]));
              maxrow=m;
              }
if(maxrow!=order)
      {
          temp=P[maxrow];
          P[maxrow]=P[order];
          P[order]=temp;

          temp2=B[maxrow];
          B[maxrow]=B[order];
          B[order]=temp2;

      }

}

void printP(double* P[30], double B[30], int m,int n)
{
      int i,j;

      printf("current matrix:\n");
      for(i=0;i<m;i++)
      {
              for(j=0;j<n;j++)
                      printf("%f ",P[i][j]);
              printf("| %f",B[i]);
              printf("\n");
      }
      printf("\n");
}

void diagonal(double* P[30],double B[30],int m,int order)//diagonal b!!
        {
      int i,j;
                double r;
                for (i=order;i<m-1;i++)
                {
               
                        r=P[i+1][order]/P[order][order];

                      for (j=order;j<m;j++)
                                {

                                P[i+1][j]-=P[order][j]*r;
                                }                       
                        B[i+1]-=B[order]*r;
                               
                }
}

void calc(double* P[30], double B[30], int m,int n)
{
        int i,j;
        double x[30],y[30];
        for (i=0;i<m;i++)
                y[i]=B[i];

        for (i=0;i<m;i++)
                x[i]=0;

        for (i=m-1;i>=0;i--)
        {
                for (j=m-1;j>i;j--)
                        y[i]-=P[i][j]*x[j];
        x[i]=y[i]/P[i][i];
        printf("x[%d]=%f\n",i,x[i]);
        }
}

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