Question

C++ Problem:

Power Plant Data. The data file power1.dat contains a power plant output in megawatts over a period of 10 weeks. Each row of data contains 7 floating-point numbers that represent 1 week's data. In developing the following programs, use symbolic constants NROWS and NCOLS to represent the number of rows and columns in the array used to store the data.

Write a function to compute and return the average value in a two-dimensional vector of type double. Assume that the corresponding function prototype is

double avgVec(const vector<vector<double> > &x);

This is a screenshot of the data file opened in notepad:

Answer 1

#include<bits/stdc++.h>
using namespace std;

int m,n;
double avgVec(const vector<vector<double> >& x)
{
double sum=0;
double count=0;

for (int i = 0; i < m; i++) {
  
for (int j = 0; j < n; j++) {
   // Add an element to sum
   sum+=x[i][j];
   count++;//increment count of number
}
  
  
}
double avg=sum/count; //Calculate average
return avg;

}

int main(int argc, char const *argv[])
{
   vector<vector<double> > matrix; //create 2-D vector

   ifstream file("power1.dat",ios_base::in);//open file
  

  

  

  
   file>>m;//no of columns
   file>>n;//no of rows
for (int i = 0; i < m; i++) {
vector<double> row; // Create an empty row
for (int j = 0; j < n; j++) {
   double d=0;
   file>>d;
row.push_back(d); // Add an element (column) to the row
}
matrix.push_back(row); // Add the row to the main vector
}

double resultavg=avgVec(matrix);
cout<<"Avearge is "<<resultavg;
   return 0;
}

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For simplicity i took file as

power1.dat

4 4
4 4 4 4
4 4 4 4
4 4 4 4
4 4 4 4

output:

Avearge is 4