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Or is it something that could be easily done without the use of modules?

I'm deeply suspicious of questions that seem too easy, but ...

It kinda depends what form you have or obtain the lower-triangle matrix in to start.

But assuming you've loaded the LT matrix into a 2d array, then "converting to a square matrix" consists of padding the upper triangle with zeros, which is one line of perl:

```#! perl -slw
use strict;
use Data::Dump qw[ pp ];

sub fillLTM {
my @lt;
my \$n = 1;
push @lt, [ splice @_, 0, \$n++ ] while @_;
return @lt;
}

## read raw data
while( my \$rawData = <DATA> ) {
## Populate LT matrix
my @lt = fillLTM( split ' ', \$rawData );
pp \@lt;;

## Pad to square matrix
push @{ \$lt[\$_] }, (0)x( @{ \$lt[-1] } - @{ \$lt[\$_] } ) for 0 .. \$#
+lt -1;;
pp \@lt;;
}

__DATA__
1 2 3 4 5 6 7 8 9 10
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15
[download]```

Produces:

```C:\test>junk
[
[1],
[2, 3],
[4, 5, 6],
[7, 8, 9, 10]
]
[
[1, 0, 0, 0],
[2, 3, 0, 0],
[4, 5, 6, 0],
[7, 8, 9, 10]
]

[
[1],
[2, 3],
[4, 5, 6],
[7, 8, 9, 10],
[11, 12, 13, 14, 15]
]

[
[1, 0, 0, 0, 0],
[2, 3, 0, 0, 0],
[4, 5, 6, 0, 0],
[7, 8, 9, 10, 0],
[11, 12, 13, 14, 15]
]
[download]```

Examine what is said, not who speaks -- Silence betokens consent -- Love the truth but pardon error.
"Science is about questioning the status quo. Questioning authority".
In the absence of evidence, opinion is indistinguishable from prejudice.

In reply to Re: Convert matrix formats by BrowserUk
in thread Convert matrix formats by naturalsciences

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