Lining up the Decimal Points

BobInNJ

I would like to output three columns of numbers with the decimal points lined up. I wrote the following piece of code which I thought would do it.

for( int i = 0; i<100; i++ ) {
	double f1 = (int)(i/20);
	double f2 = 3.1415\*i;
	double f3 = 3.1415\*(f2+3);
	cout.width( 10 );
	cout.precision( 4 );
	cout << std::left << f1 << " ";
	cout.width( 10 );
	cout << std::left << f2 << " ";
	cout.width( 10 );
	cout << std::left << f3 << endl;
}

However, the decimal points are not lined up. Also, I want to do this in C++ not C. That is, I do not want to use, printf, fprintf or sprintf. How do I get the decimal points to line up vertical? Thanks Bob

Malli_S

Check if this is helpful.

{
cout << fixed;
for( int i = 0; i<10; i++ ) {
double f1 = (int)(i/20);
double f2 = 3.1415*i;
double f3 = 3.1415*(f2+3);
std::cout << std::setfill (' ') << std::setw (10);
cout.width( 10 );
cout.precision( 4 );
cout << f1 << " ";
cout.width( 10 );
cout << f2 << " ";
cout.width( 10 );
cout << f3 << endl;
}

	getch();
}

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-Malli...! :rose:****

BobInNJ

Thanks for the response. However, it failed to produce the results I wanted. Here is part of the output that I got:

     0          0      9.425
     0      3.142      19.29
     0      6.283      29.16
     0      9.425      39.03
     0      12.57       48.9
     0      15.71      58.77

The decimal points are not lined up. What I want is:

     0      0.0         9.425
     0      3.142      19.29
     0      6.283      29.16
     0      9.425      39.03
     0     12.57       48.9
     0     15.71       58.77

In what I want the decimal points are all in the same column.

David Crow

Have you tried removing std::left?

"One man's wage rise is another man's price increase." - Harold Wilson

"Fireproof doesn't mean the fire will never come. It means when the fire comes that you will be able to withstand it." - Michael Simmons

"You can easily judge the character of a man by how he treats those who can do nothing for him." - James D. Miles

BobInNJ

I tried it with std::left, without std::left and with std::right. In all three cases it did not work. What I believe the problem is that there is no way to specified a fixed number of digits along with a fixed number of digits to the right of the decimal point. I think I am going to go use sprintf and then send the output the string sprintf produces. It is not the "C++ way" of doing things but it works. I want to thank the group for their responses. Bob

David Crow

Try adding cout << setiosflags(ios::fixed) right before the for() loop.

"One man's wage rise is another man's price increase." - Harold Wilson

"Fireproof doesn't mean the fire will never come. It means when the fire comes that you will be able to withstand it." - Michael Simmons

"You can easily judge the character of a man by how he treats those who can do nothing for him." - James D. Miles

Malli_S

But at my end I'm getting proper output. Have a look at this[^].

[Delegates] [Virtual Desktop] [Tray Me !]
-Malli...! :rose:****

BobInNJ

David, Adding the line:

cout << setiosflags(ios::fixed);

before the for loop did the trick. The program now works as expected. I am happy. I thank you and all the other people who responded to my post for their help in this matter. Bob