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### Re^2: sort hash of arrays of arrays

 on Oct 31, 2012 at 14:43 UTC ( #1001676=note: print w/ replies, xml ) Need Help??

in reply to Re: sort hash of arrays of arrays
in thread sort hash of arrays of arrays

Ok, sorry, it's not a multi-dimensional array this way. In my script I build it up from a tab-delimited text file as follows:

my %hash; while (<FILE>) { chomp; my @line = split("\t"); push(@{\$hash{\$line[1]}}, [@line]); }

This, at the end, is a 3-D array.
How can I do the sort based on the 2nd item of the innermost array?

Thank you,

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Re^3: sort hash of arrays of arrays
by BrowserUk (Pope) on Oct 31, 2012 at 15:16 UTC
How can I do the sort based on the 2nd item of the innermost array?

Okay. So you have a hash of arrays of arrays; something like this:

{ 1 => [ [1, 2, 3], [6, 7, 8], [16, 17, 18], [26, 27, 28] ], 2 => [ [2, 3, 4], [7, 8, 9], [17, 18, 19], [27, 28, 29] ], 3 => [ [3, 4, 5], [8, 9, 10], [18, 19, 20], [28, 29, 30] ], 4 => [ [4, 5, 6], [9, 10, 11], [19, 20, 21], [29, 30, 31] ], }

The second item of which innermost array?

Each outer array contains multiple arrays. Which of those do you which to sort on? The first? The last? All of them?

With the rise and rise of 'Social' network sites: 'Computers are making people easier to use everyday'
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.

I'd like to sort the outer arrays of each hash item (1-4) separately, based on the second item of the inner arrays to finally have something like:

{ 1 => [ [26, 27, 28], [16, 17, 18], [6, 7, 8], [1, 2, 3] ], 2 => [ [27, 28, 29], [17, 18, 19], [7, 8, 9], [2, 3, 4], ], 3 => [ [28, 29, 30], [18, 19, 20], [8, 9, 10], [3, 4, 5] ], 4 => [ [29, 30, 31], [19, 20, 21], [9, 10, 11], [4, 5, 6] ], }

So for the first set, values 2, 7, 17 and 27 were compared to get the right order.
I hope this clarifies my problem.

Thanks

Then you need to do one sort for each key in the hash like this:

@{ \$hash{\$_} } = sort{ \$b->[1] <=> \$a->[1] } @{ \$hash{\$_} } for keys % +hash;; pp \%hash;; { 1 => [[26, 27, 28], [16, 17, 18], [6, 7, 8], [1, 2, 3]], 2 => [[27, 28, 29], [17, 18, 19], [7, 8, 9], [2, 3, 4]], 3 => [[28, 29, 30], [18, 19, 20], [8, 9, 10], [3, 4, 5]], 4 => [[29, 30, 31], [19, 20, 21], [9, 10, 11], [4, 5, 6]], }

With the rise and rise of 'Social' network sites: 'Computers are making people easier to use everyday'
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.

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