columns and rows

[jbennett]

I am trying to figure out how I would store the values for the total cols and rows so my print_array function would output them. I am having issues understanding what I am doing wrong.

#include <iostream>
#include <iomanip>
using namespace std;

const int row = 4, col = 5, width = 8;
void format();
void print_array(double n[][col]);
void total_cols(double[][col]);
void total_rows(double[][col]);

int main()
{
	double numbers[row][col] = {{4.2,4.1,6.3,6.2},{5.5,4.6,4.7,5.0},{6.3,5.8,4.6,5.5}};
	format();
	print_array(numbers);

return 0;
}

void print_array(double n[][col])
{
	for (int i = 0; i < row - 1; i++)
	{
		for (int j = 0; j < col; j++)
			cout << setw(width) << n[i][j];
		cout << endl;
	}

	for (int k=0;k<col;k++)
		cout << setw(width) << "-------";
	cout << endl;

	for (int j = 0; j < col; j++)
		cout << setw(width) << n[row - 1][j];
	cout << endl;

}

void format()
{
	cout << setprecision(2);
	cout << setiosflags(ios::fixed | ios::showpoint);
}

void total_cols(double n[][col])
{
	double i, j, total = 0;

	for (i = 0; i < 4; ++i)
	{
		for (j = 0; j < 4; ++j)
		{
			total = total + arr[i][j];
		}
		cout << i << "=" << total << endl;

		total = 0;
	}
}

}

void total_rows(double n[][col])
{
	double i, j, total = 0;

	for (i = 0; i < 4; ++i)
	{
		for (j = 0; j < 4; ++j)
		{
			total = total + arr[i][j];
		}
		cout << i << "=" << total << endl;

		total = 0;
	}
}

[salem c]

Are you trying to end up with something like this?

1 2 = 3
3 4 = 7
--------
4 6

[jbennett]

yep! exactly!

[salem c]

Something like this (untested).

void print_array(double n[][col])
{
	double colTotals[col] = { 0 };
	for (int r = 0; r < row; r++)
	{
		double rowTotal = 0.0;
		for (int c = 0; c < col; c++) {
			cout << setw(width) << n[r][c];
			rowTotal += n[r][c];
			colTotals[c] += n[r][c];
		}
		cout << setw(width) << rowTotal << endl;
	}

	for (int c = 0; c < col; c++)
		cout << setw(width) << "-------";
	cout << endl;

	for (int c = 0; c < col; c++)
		cout << setw(width) << colTotals[c];
	cout << endl;
}

[lastchance]

#include <iostream>
#include <iomanip>
#include <string>
#include <valarray>
using namespace std;

const int WIDTH = 8;
#define SW << setw( WIDTH ) <<


template <typename T> ostream &operator << ( ostream &strm, const valarray<T> &V )
{
   for ( T e : V ) strm SW e << " ";
   return strm;
}


int main()
{
   valarray<double> A = { 4.2, 4.1, 6.3, 6.2,   5.5, 4.6, 4.7, 5.0,   6.3, 5.8, 4.6, 5.5 };
   int row = 3, col = A.size() / row;

   cout << fixed << setprecision( 1 );
   for ( int n = 0; n < A.size(); n += col )
   {
      valarray<double> ROW = A[slice(n,col,1)];
      cout << ROW << " | " SW ROW.sum() << '\n';
   }
   cout << string( col * ( WIDTH + 1), '-' ) << '\n';
   for ( int c = 0; c < col; c++ )
   {
      valarray<double> COL = A[slice(c,row,col)];
      cout SW COL.sum() << " ";
   }
   cout << '\n';
}

     4.2      4.1      6.3      6.2  |     20.8
     5.5      4.6      4.7      5.0  |     19.8
     6.3      5.8      4.6      5.5  |     22.2
------------------------------------
    16.0     14.5     15.6     16.7 

[jbennett]

I appreciate the help everyone, I was kind of hoping to figure out how I can fix the code I wrote rather than get a whole new code. I am doing something wrong just not sure how to fix it. I think the print_array function is correct but the total_cols and total_rows are in need of some fixing, I could be wrong though. The comment from my professor said "How would you store those values back in the array so the print_array function would output them?" I am not sure the answer.

[lastchance]

Your code doesn't compile.

Make sure you call your arrays consistent things within one function. You can't call them n[][] on lines 45 and 63, then arr[][] on lines 53 and 71.

Also i < 4 doesn't correspond to your number of rows, and there isn't much logic to writing i=total.

From what your professor is saying, and the fact that your declared size of array has a spare row and column, I presume he wants you to put the row totals in the last column and the column totals in the last row, rather than printing them out separately.

[jbennett]

So I definitely understand my inconsistency of the arrays, I thank you for pointing that out. When I thange arr to n int the total_cols and total_rows functions I am getting an error that says an expression must have an intergral or an unscoped enum type attached to n[i][j]. Not sure what its meaning.

#include <iostream>
#include <iomanip>
using namespace std;

const int row = 4, col = 5, width = 8;
void format();
void print_array(double n[][col]);
void total_cols(double[][col]);


int main()
{
	double numbers[row][col] = { { 4.2,4.1,6.3,6.2 },{ 5.5,4.6,4.7,5.0 },{ 6.3,5.8,4.6,5.5 } };
	format();
	print_array(numbers);

	return 0;
}

void print_array(double n[][col])
{
	for (int i = 0; i < row - 1; i++)
	{
		for (int j = 0; j < col; j++)
			cout << setw(width) << n[i][j];
		cout << endl;
	}

	for (int k = 0; k<col; k++)
		cout << setw(width) << "-------";
	cout << endl;

	for (int j = 0; j < col; j++)
		cout << setw(width) << n[row - 1][j];
	cout << endl;

}

void format()
{
	cout << setprecision(2);
	cout << setiosflags(ios::fixed | ios::showpoint);
}

void total_cols(double n[][col])
{
	double i, j, total = 0;

	for (i = 0; i < 5;i++)
	{
		for (j = 0; j < 5; ++j)
		{
			total = total + n[i][j];
		}
		cout << i << "=" << total << endl;

		total = 0;
	}
}
void total_rows(double[][col])
{
	double i, j, total = 0;

	for (i = 0; i < 4; i++)
	{
		for (j = 0; j < 4; ++j)
		{
			total = total + n[i][j];
		}
		cout << i << "=" << total << endl;

		total = 0;
	}
}

[lastchance]

In both of your totalling routines you have declared i, j to be doubles. If they are array indices they should be ints. In fact, a good place to declare them as such is in the "for" statements themselves (lines 49, 51, 64 and 66), just as was done in routine print_array.

Array n[][] is not declared on line 60.

In neither totalling routine do your loop ranges reflect the actual size of your array.

You are not doing what your professor asked - re-read my last post.