this code does not work... help!

OlesadeMontserrat · Jul 20, 2000

this is my code. The function identity at the end does not work. Could you tell me why. #include<stdio.h> #include<stdlib.h> #define max 100 int t, rowA, rowB, colA, colB, rowR, colR, arrayA[max][max], arrayB[max][max], arrayR[max][max]; void INPUT (int t, int arrayA[][max], int arrayB[][max]); void DISPLAY (int t, int arrayA[][max], int arrayB[][max], int arrayR[][max]); void MENU (); void ReENTER(); void ADDITION (int arrayR[][max]); void SUBTRACTION (int arrayR[][max]); void MULTIPLY (int arrayR[][max]); void DETERMINANT (); void TRANSPOSE (int arrayR[][max]); void INVERSE (int arrayR[][max]); void IDENTITY (int arrayR[][max]); int main () {   int  re, t, Nmatrix;      printf("\n*************************************\n&quot

;   printf("\n\nEnter number of matricies, 1 or 2\n&quot

;   printf("\n*************************************\n&quot

;   scanf("%d",&Nmatrix);   for(t=1; t< (Nmatrix+1); t++)     INPUT(t, arrayA, arrayB);   for(t=1; t< (Nmatrix+1); t++)     DISPLAY (t, arrayA, arrayB, arrayR);      MENU();    } /***********************************************************************/ void INPUT(int t, int arrayA[][max], int arrayB[][max]) {   int n,m,row,col;   printf("*************************************\n&quot

;   printf("\n\nEnter array number %d\n\n",t);   printf("*************************************\n&quot

;      printf("Enter number of columns\n&quot

;      scanf("%d", &col);   fflush(stdin);    /*flush the input stream in case of bad input*/         printf("Enter number of rows\n&quot

;      scanf("%d", &row);   fflush(stdin);   /* flush the input stream in case of bad input*/      for (n=0; n<row; n++){     printf("\n\n&quot

;     for (m=0; m<col; m++){       printf("Enter element for row %d, column %d\n", n, m);       if (t==1) { scanf("%d", &arrayA[n][m]); rowA = row; colA = col;       }       else if (t==2){   scanf("%d", &arrayB[n][m]); rowB = row; colB = col;       }     }   }    } /************************************************************************/ /************************************************************************/ void DISPLAY (int t, int arrayA[][max], int arrayB[][max], int arrayR[][max]) {   int n, m, k, N, rowI, colI, array[max][max];      if (t==1){     printf("\n\nThis is matrix number %d", t);     for (n=0; n<rowA; n++){       printf("\n\n&quot

;       for (m=0; m<colA; m++) printf("%d\t", arrayA[n][m]);     }         printf("\n&quot

;   }      if (t==2){     printf("\n\nThis is matrix number %d", t);     for (n=0; n<rowB; n++){       printf("\n\n&quot

;       for (m=0; m<colB; m++) printf("%d\t", arrayB[n][m]);     }   }          if (t==3){     for (n=0; n<rowR; n++){       printf("\n\n&quot

;       for (m=0; m<colR; m++) printf("%d\t", arrayR[n][m]);     }     printf("\n\nThis is matrix number %d, it will be over written next time a calculation is performed.",t);     printf("  This matrix can replace the perminat matricies(1 and 2) by selecting number 1 from the menu\n&quot

;   }   printf("\n&quot

;      /*display the product of two matrices*/      if (t==4){     for (n=0; n<rowA; n++){       printf("\n\n&quot

;      /*Spacing between the lines*/       for (m=0; m<colB; m++){ printf("\t&quot

;      /*spacing between columns*/          for (k=0; k<colR; k++)   printf("\n\n&quot

; printf("%d\t", arrayR[n][m]);       }     }     printf("\n\nThis is matrix number 3, it will be over written next time a calculation is performed.&quot

;     printf("  This matrix can replace the perminat matricies(1 and 2) by selecting number 1 from the menu\n&quot

;     /*t=display*/     printf("\n&quot

;   }   /*display the transpose of matrix A*/      if (t==5)     {       for(n=0; n<rowA; n++) {   for(m=0; m<colA; m++)     {       arrayR[m][n]=arrayA[n][m];     } }       printf("\n\t\n&quot

;       for(n=0; n<rowA; n++) {   printf("\t&quot

;   for(m=0; m<colA; m++)     {       printf("\t&quot

;       printf("\t%d", arrayR[n][m]);     }   printf("\n&quot

;   printf("\n\t\n&quot

; }       printf("\n&quot

;       printf("\n\nThis is matrix number 3, it will be over written next time a calculation is performed.&quot

;       printf("  This matrix can replace the perminat matricies(1 and 2) by selecting number 1 from the menu\n&quot

;       /*t=display*/       printf("\n&quot

;     /*display the transpose of matrix B*/        if (t==6)     {     for(n=0; n<rowB; n++)       {       for(m=0; m<colB; m++) {   arrayR[m][n]=arrayB[n][m]; }       }       printf("\n\t\n&quot

;       for(n=0; n<rowB; n++) {   printf("\t&quot

;   for(m=0; m<colB; m++)     {       printf("\t&quot

;       printf("\t%d", arrayR[n][m]);     }   printf("\n&quot

;   printf("\n\t\n&quot

; }       printf("\n&quot

;       printf("\n\nThis is matrix number 3, it will be over written next time a calculation is performed.&quot

;       printf("  This matrix can replace the perminat matricies(1 and 2) by selecting number 1 from the menu\n&quot

;       /*t=display*/       printf("\n&quot

;            }         }   /*display the identity matrix*/      if (t==7)     {       for(n=0; n<rowR; n++) {   for(m=0; m<colR; m++)     {       if (n==m) arrayR[n][m]=array[1][1];       if (n!=m)     arrayR[n][m]=array[0][0];     } }       printf("\t%d", arrayR[n][m]);     }      printf("\n&quot

;   printf("\n\nThis is matrix number 3, it will be over written next time a calculation is performed.&quot

;   printf("  This matrix can replace the perminat matricies(1 and 2) by selecting number 1 from the menu\n&quot

;   /*t=display*/   printf("\n&quot

; } /*******************************************************************/ /********************************************************************/ void MENU () {   int m;   printf("\n\n=================================================\n&quot

;   printf("What would you like to do?\n&quot

;   printf("\t1:\tReplace a matrix\n&quot

;  /*try slashf*/   printf("\t2:\tDo an addition\n&quot

;   printf("\t3:\tDo a subtraction\n&quot

;   printf("\t4:\tDo a multiplication\n&quot

;   printf("\t5:\tCalculate a determinant\n&quot

;   printf("\t6:\tCalculate the transposed matrix\n&quot

;   printf("\t7:\tCalculate the inverse matrix\n&quot

;   printf("\t8:\tDo you want to view the identity matrix\n&quot

;   printf("\t9:\tExit\n&quot

;   printf("=================================================\n&quot

;   scanf("%d", &m);      if (m==1) ReENTER();   if (m==2) ADDITION(arrayR);   if (m==3) SUBTRACTION (arrayR);   if (m==4) MULTIPLY (arrayR);   if (m==6) TRANSPOSE (arrayR);   if (m==8) IDENTITY (arrayR); } /************************************************************/ /*************************************************************/ void ReENTER () {   int new, n, m;      printf("Would you like to:\n&quot

;   printf("1:\tRe-enter a matrix\n&quot

;   printf("2:\tReplace a matrix with a matrix just calculated\n&quot

;   scanf("%d", &new);      if (new == 1){     printf("Which matrix would you like to re-enter?\n&quot

;     scanf("%d",&t);     INPUT(t, arrayA, arrayB);     DISPLAY (t, arrayA, arrayB, arrayR);   }      if (new == 2){     printf("Which matrix do you want to be replaced?\n&quot

;     scanf("%d", &t);     if (t==1){       for (n=0; n<rowR; n++){        for (m=0; m<colR; m++) arrayA[n][m] = arrayR[n][m];        }     }     if (t==2){       for (n=0; n<rowR; n++){ for (m=0; m<colR; m++) arrayB[n][m] = arrayR[n][m];       }     }   }      MENU(); } /**************************************************************/ /***************************************************************/ void ADDITION (int arrayR[][max]) {   int n,m;      if ( (rowA != rowB) ¦¦ (colA != colB) ){     printf("\nThe two matricies are not of the same size!\n&quot

;     MENU ();   }   t=3;   rowR = rowA; colR = colA;      for (n=0; n<rowR; n++){     for (m=0; m<colR; m++)       arrayR[n][m] = arrayA[n][m] + arrayB[n][m];   }   printf("This is the resulting matrix:\n&quot

;   DISPLAY (t, arrayA, arrayB, arrayR);   MENU ();    } /**************************************************************/ /****************************************************************/ void SUBTRACTION (int arrayR[][max]) {   int sub,n,m;      if ( (rowA != rowB) ¦¦ (colA != colB) ){     printf("\nThe two matricies are not of the same size!\n&quot

;     MENU ();   }      t=3;   rowR = rowA; colR = colA;      printf("Would you like to:\n&quot

;   printf("1:\tSubtract matrix 1 from 2\n&quot

;   printf("2:\tSubtract matrix 2 from 1\n&quot

;   scanf("%d",&sub);      if (sub==1){     for (n=0; n<rowR; n++){       for (m=0; m<colR; m++) arrayR[n][m] = arrayA[n][m] -  arrayB[n][m];     }   }      if (sub==2){     for (n=0; n<rowR; n++){       for (m=0; m<colR; m++) arrayR[n][m] = arrayB[n][m] -  arrayA[n][m];     }   }      MENU (); } /***********************************************************************************/ /**********************************************************************************/ /* Multiply matrix A by matrix B, storing the         * * product in matrix R, where all three matrices are    * * a by a in size:                                       * *                  a-1                                  * *   R[ n ][ m ] = SUM m1[ n ][ k ] * m2[ k ][ m ]      * *                  k=0                                  * * and 0 <= n,m < a.                                     */ void MULTIPLY (int arrayR[][max]) {   int mul, m,n, k, colR;   if (colA != rowB){     printf("\n Can multiply the matrices because the number of columns in A different to the number of rows in B\n&quot

;     MENU ();   }   t=4;      colR=colA; colR=rowB;   printf("\n\n%d\n\n", colR);      for ( n = 0; n < rowA; n++ )     for ( m= 0; m < colB; m++ ) {       arrayR[n][m ] = 0;       for ( k = 0; k < colR; k++ ){ arrayR[n][m] += arrayA[n][k] * arrayB[k][m];       }     }      printf("This is the resulting matrix:\n&quot

;   DISPLAY (t, arrayA, arrayB, arrayR);   MENU (); } /****************************************************************************************************/ /****************************************************************************************************/ void TRANSPOSE (int array[][max]) {   int n, m,k, trans;     printf("Would you like to:\n&quot

;   printf("1:\tFind the transpose of matrix A\n&quot

;   printf("2:\tFind the transpose of matrix B\n&quot

;   scanf("%d", &trans);      t=5;      if (trans == 1){     printf("\n\nYou will calculate the transpose of matrix A\n&quot

;     for(n=0; n<rowA; n++)       for(m=0; m<colA; m++) arrayR[m][n] = arrayA[n][m];     printf("This is the resulting matrix:\n&quot

;     DISPLAY(t, arrayA, arrayB, arrayR);     MENU();     printf("\n&quot

;   }      t=6;   if (trans == 2){     printf("\n\nYou will calculate the transpose of matrix B\n&quot

;     for(n=0; n<rowB; n++)       for(m=0; m<colB; m++) arrayR[m][n] = arrayB[n][m];               printf("This is the resulting matrix:\n&quot

;     DISPLAY(t, arrayA, arrayB, arrayR);     MENU();   } } /*************************************************************************************/ /************************************************************************************/ /*VIEW THE IDENTITY MATRIX*/ void IDENTITY (int array[][max]) {   int n, m,k, colI, rowI, arrayI[max][max];         printf("Enter number of columns\n&quot

;      scanf("%d", &colR);   fflush(stdin);    /*flush the input stream in case of bad input*/   printf("Enter number of rows\n&quot

;   scanf("%d", &rowR);   fflush(stdin);   /* flush the input stream in case of bad input*/   printf("\nthis is rowR %d\n", rowR);   printf("\nthis is colR %d\n",colR);      t=7;      for(n=0; n<rowR; n++){     for(m=0; m<colR; m++){       if (n==m) { arrayR[n][m] = array[1][1];;       } else if (n!=m) arrayR[n][m] = array[0][0];     }     printf("\tarray1 is%d\n", arrayR[n][m]);       }   printf("\tarray2 is%d\n", arrayR[n][m]);   printf("This is the resulting matrix:\n&quot

;   DISPLAY(t, arrayA, arrayB, arrayR);   MENU();    }

rajlobban · Jul 20, 2000

i think normally you would fflush the io streams before you get data.   fflush(stdin);    /*flush the input stream in case of bad input*/   scanf("%d", &colR);      printf("Enter number of rows\n&quot

;   fflush(stdin);   /* flush the input stream in case of bad input*/   scanf("%d", &rowR);    but this is just a wild guess.... presently i ma not around a C compiler to test the prog...but try this. if it is a prob with fflush().

ami123 · Jul 21, 2000

Hey Buddy,   Didnt get the code of Ur identity matrix at all. U have written ---- arrayR[n][m] = array[1][1];;       } else if (n!=m) arrayR[n][m] = array[0][0]; --------- U havent initialised the array 'array' so all the values are 0 and U dont want that modify the code to ---- arrayR[n][m] = 1;       } else if (n!=m) arrayR[n][m] = 0; thanks amit amit <a href=mailto: crazy_indian@mailcity.com> crazy_indian@mailcity.com</a> <a href= > </a> to bug is human to debug devine

NadadurSreedhar · Aug 28, 2000

Identity matrix is one in which whose rows and columns
are equal the value is 1 otherwise 0.
For Identity matrix code is
for(i=0;i<row;i++)
for(j=0;j<col;j++)
{
if (i==j)
a[j]=1;
else
a[j]=0;
}

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this code does not work... help!

OlesadeMontserrat

Programmer

rajlobban

Programmer

ami123

MIS

NadadurSreedhar

Programmer

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