how to printf a matrix like this

madM has asked for the wisdom of the Perl Monks concerning the following question:

Hi Monks! I´m trying to print a 4 x 4 matrix but i don´t really know how to round the numbers and print them at the same time with printf with a spacing of ,for example, 4 Here´s what i wrote: the numbers are stored in a hash of hashes with the keys A B C and D

A => A 6.8888
B => B  6.8888
C => C 6.8888
D => D 6.8888
[download]

the rest of the numbers are 0.1111

my @letters=qw(A B C D);
print '    ';
    foreach my $key (@letters){          
        printf ("%s", $key);
    }
    
    "\n";
    
    foreach my $key (@letters) {
        print $key,' ';
        foreach my $key2 (@letters) {
            printf ("%.1f" , $A->{$key}->{$key2});
        }
        print "\n";
    }
}
[download]

Here´s what im trying to get:


      A      B      C      D
A    6.8    0.1    0.1    0.1 
B    0.1    6.8    0.1    0.1    
C    0.1    0.1    6.8    0.1
D    0.1    0.1    0.1    6.8
[download]

Comment on how to printf a matrix like this Select or Download Code

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Re: how to printf a matrix like this by RichardK (Parson) on Feb 11, 2014 at 11:46 UTC
The explanation of how to use printf formatting is in the help for sprintf. (the printf help really should point to this too). To fix your problem you need to set a minimum width, try something like this :- `printf "%6.1f",$var;`	[reply] [d/l]
Re^2: how to printf a matrix like this by kcott (Archbishop) on Feb 12, 2014 at 09:22 UTC
"The explanation of how to use printf formatting is in the help for sprintf. (the printf help really should point to this* too)."* [my emphasis] The printf documentation does point to this. It starts with: "Equivalent to print `FILEHANDLE`sprintf`(FORMAT, LIST)`, ..." [FWIW, madM has already been provided with that information (in Re: printf matrix) as well as example `sprintf` usage in a number of places.] -- Ken	[reply] [d/l] [select]
Re^2: how to printf a matrix like this by madM (Beadle) on Feb 11, 2014 at 12:12 UTC
thakyou! that really helped :)	[reply]
Re: how to printf a matrix like this by Anonymous Monk on Feb 11, 2014 at 11:11 UTC
This seems interesting Re: printing Matrix	[reply]
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Re: how to printf a matrix like this by McA (Priest) on Feb 11, 2014 at 11:09 UTC
Hi, IMHO the most generic approach would be to store the result matrix into an array of arrays. While doing so, you could remember the most needed space for a column. After that you know the minimum space for each column and the adjustment needed when printing. After that you print each row of the array of arrays knowing how to adjust the length of the output. Regards McA	[reply]