Help with outut display "No data"

[abby11]

Hello,

I made a simple code to process the root mean square of a sequence of user entered variables. It works for that task but I cannot figure out how to specify that no data is available for values less than 0.

-1 stops the prompt and starts the calculation. If -1 or -2 is the first input I need it to display "No data" and stop like this:

Enter a positive number (-1 exits): -1
No data

Here is my code thus far:

#include <iostream>
#include <cmath> 

using namespace std;

int main()
{
	double nSum = 0, counter = 0, nDivide, rms;
	 for(;;) //loop to gather positive numbers from user stops if -1 is entered
    {
        double number;
        cout << "Enter a positive number (-1 exits): ";
		cin >> number;
		counter++;

		double nSquare = number*number; //squares user numbers and adds them to get the sum
        // stops asking if umber is -1
        if (number == -1) 
        {
			break;
		}
		 nSum += nSquare;
		 nDivide = nSum/counter;
		 rms = sqrt(nDivide);
	 }
	cout << "Answer = " << rms << endl;
}

Any help on how to get this to display "No data" as well would be appreciated.

[whitenite1]

@abby11

The program will display "No data", with any negative number, and will NOT add it to nSum. I used any negative number only because in your post, you mention -1 or -2 as input.

// Root Mean Square.cpp : Defines the entry point for the console application.
//
#include <iostream>
#include <cmath> 

using namespace std;

int main()
{
	double nSum = 0, counter = 0, nDivide, rms, number;
	number = 0.0;
	while ( number  >= 0) //loop to gather positive numbers from user. Stops if  negative is entered
    {
        cout << "Enter a positive number (-1 exits): ";
		cin >> number;
		counter++;
		if ( number >=0)
		{
		double nSquare = number*number; //squares user numbers and adds them to get the sum
         nSum += nSquare;
		 nDivide = nSum/counter;
		 rms = sqrt(nDivide);
		 cout << "Answer = " << rms << endl;
		}
	 }
	cout  << endl << endl << "No data" << endl << endl;
}

[abby11]

Thank you the while loop fixed the No data problem perfect. How would I modify it to only display "Answer = " and the rms after the user enters a negative number?

Right now it is printing the rms after each number is added by the user until they enter a negative number.

I tried moving the cout << "Answer = " << rms << endl; out of the loop and moving the calculations

double nSquare = number*number;
         nSum += nSquare;
		 nDivide = nSum/counter;
		 rms = sqrt(nDivide);

outside of it but nothing seemed to work.

[whitenite1]

@abby11
Move just the cout << "Answer..." to just below the 'No Data' statement, Maybe even change the wording to "No more data..".

[abby11]

Hello still having no luck with it, it displays the root mean sum calculation after each user entry. I tried adding an else if statement but that did not fix it either.

#include <iostream>
#include <cmath> 

using namespace std;

int main()
{
	double num = 0, nSum=0, nDivide=0, rms=0;
	int counter=0;
	while(num >= 0)
	{
		cout << "Enter a positive number (-1 exits): ";
		cin >> num;
		
		counter++;
			double nSquare =pow(num,2); //squares user numbers 
			nSum += nSquare;
			nDivide = nSum/counter;
			rms = sqrt(nDivide);
		if (num >= 0)
		{
			cout << "Answer = " << rms << endl;
		}
		else if(num <= -1)
		{
			cout << "No data" << endl;
		}
	}
}

[whitenite1]

@abby11
You didn't just move the one line, but changed the program. Here it the program with the change I mentioned.

// Root Mean Square.cpp : Defines the entry point for the console application.
//
#include <iostream>
#include <cmath> 

using namespace std;

int main()
{
	double nSum = 0, nDivide, rms, number;
	number = 0.0;
	int counter = 0;
	double nSquare;
	while ( number  >= 0) //loop to gather positive numbers from user stops if -1 is entered
    {
        cout << "Enter a positive number (-1 exits): ";
		cin >> number;
		counter++;
		if ( number >=0)
		{
		 nSquare = number*number; //squares user numbers and adds them to get the sum
         nSum += nSquare;
		 nDivide = nSum/counter;
		 rms = sqrt(nDivide);
		
		}
	 }
	cout  << endl << endl << "No more Data.." << endl;
	cout << "Final answer = " << rms << endl;
}

[DSLq5Di1]

@abby11
You have a counter variable.. so put it to use! http://ideone.com/iU1Co

[abby11]

Looks great its working now thanks again.