head

C<Data::Reshapers::CrossTabulate> package module has data cross tabulation functions over
different data structures coercible to full-arrays.


use Data::Reshapers;
use Data::Reshapers::CrossTabulate;


my $xtab1 = CrossTabulate(@tbl, 'passengerClass', 'passengerSex');
my $xtab2 = CrossTabulate(@tbl, 'passengerClass', 'passengerSex', 'passengerAge');


my @tbl2 = $csv.csv(in => $fileName, headers => "none");
my $xtab3 = CrossTabulate(@tbl, 1, 3);
my $xtab4 = CrossTabulate(@tbl, 1, 3, 2);



unit module Data::Reshapers::CrossTabulate;

#===========================================================
our proto CrossTabulate(|) is export {*}

#-----------------------------------------------------------
#| Count or sum using two or three keys respectively
multi CrossTabulate(@tbl, Str:D $rowVarName, Str $columnVarName?, Str $valueVarName? ) {

    # One-liner summarizing the implementation below
    #my %res = @tbl.classify( { ($_{$rowVarName}, $_{$columnVarName}) } ).duckmap({ $_.duckmap({$_{$valueVarName}}).sum });

    # Coerce into array-of-hashes
    my Hash @arr-of-hashes;
    try {
        @arr-of-hashes = @tbl
    }

    if $! {
        note 'The first argument is expected to be an array that can be coerced into an array-of-hashes if the rest of the arguments are strings.';
        return Nil;
    }

    # Break-down into groups
    my %res;
    try {
        if $columnVarName {
            %res = @arr-of-hashes.classify({ $_{($rowVarName, $columnVarName)} })
        } else {
            # If no second column is specified classify with "default" first level key,
            # in order to obtain %res that is similar to 'main' case.
            %res = @arr-of-hashes.classify({ ('ONE', $_{$rowVarName}) })
        };
    }

    if $! {
        note "Not all records have the keys $rowVarName and $columnVarName.";
        return Nil;
    }

    # Summarize per group
    my %res2;
    if $valueVarName {

        try {
            %res2 = do for %res.kv -> $k, $v {
                $k => Hash( do for $v.kv -> $k1, $v1 { $k1 => $v1.map({ $_{$valueVarName} }).sum } )
            }
        }

        if $! {
            note "Not all records allow summation with the key $valueVarName.";
            return Nil;
        }

    } else {

        %res2 = do for %res.kv -> $k, $v {
            $k => Hash( do for $v.kv -> $k1, $v1 { $k1 => $v1.elems } )
        }

    }

    # If no second column is specified return single hash
    if not $columnVarName {
        %res2 = %res2{'ONE'}
    }

    # Result
    return %res2;
}

#-----------------------------------------------------------
#| Count or sum using two or three indexes respectively
multi CrossTabulate(@tbl, UInt:D $rowIndex, UInt $columnIndex?, UInt $valueIndex?) {

    # One-liner summarizing the implementation below
    #my %res = @tbl.classify( { ($_[$rowIndex], $_[$columnIndex]) } ).duckmap({ $_.duckmap({$_[$valueIndex]}).sum });

    # Note that we could have (likely) optimized the case when @tbl an array-of-arrays using
    # if @tbl.isa(Array[Array]) { ...

    if @tbl.isa(Array) and @tbl.shape.elems > 2 {
        note 'Cannot work with multi-dimensional arrays. Sorry.';
        return Nil;
    } elsif @tbl.isa(Array)  and @tbl.shape.elems == 2 {
        my $arr = @tbl.flat.rotor( @tbl.shape()[1] );
        return CrossTabulate( $arr, $rowIndex, $columnIndex, $valueIndex )
    }

    # Coerce into array-of-arrays
    my Positional @arr-of-arrays;
    try {
        @arr-of-arrays = @tbl
    }

    if $! {
        note 'The first argument is expected to be an array that is or can be coerced into an array-of-arrays if the rest of the arguments are integers.';
        return Nil;
    }

    # Break-down into groups
    my %res;
    try {
        with $columnIndex {
            %res = @arr-of-arrays.classify({ $_[($rowIndex, $columnIndex)] });
        } else {
            %res = @arr-of-arrays.classify({ ('ONE', $_[($rowIndex)]) });
        }
    }

    if $! {
        note "Not all records have the indexes $rowIndex and $columnIndex.";
        return Nil;
    }

    # Summarize per group
    my %res2;
    with $valueIndex {

        try {
            %res2 = do for %res.kv -> $k, $v {
                $k => Hash( do for $v.kv -> $k1, $v1 { $k1 => $v1.map({ $_[$valueIndex] }).sum } )
            }
        }

        if $! {
            note "Not all records allow summation with the index $valueIndex.";
            return Nil;
        }

    } else {

        %res2 = do for %res.kv -> $k, $v {
            $k => Hash( do for $v.kv -> $k1, $v1 { $k1 => $v1.elems } )
        }

    }

    # If no second column is specified return single hash
    without $columnIndex {
        %res2 = %res2{'ONE'}
    }

    # Result
    return %res2;
}

root

JoinAcross

Reshapers

React

=begin React :component<HeaderCol> :id<menu> 
=para L<Documentation|/doc/introduction>
=para L<Modules| /mods>
=para L<Examples| file:../examples/index.podlite>
=para L<Download |file:../download/index.podlite>
=para L<About|file:../about/index.podlite>
=para 🔍 K<⌘K>/K<ctrl-K>
=end React


=begin React :component<HeaderCol> :id<footer>  
=begin nested :!nested
=item1 B<Language>
    =item2 L<Get started|file:../getting-started/getting-started.podlite>
    =item2 L<Why Raku?|/doc/language/faq#Why-should-I-learn-Raku-What's-so-great-about-it>
    =item2 L<Try Raku|https://glot.io/new/raku>
    =item2 L<Raku cheat sheet|https://github.com/Raku/mu/blob/master/docs/Perl6/Cheatsheet/cheatsheet.txt>
    =item2 L<empty|#>
    =item2 L<empty|#>
    =item2 L<empty|#>
    =item2 L<Raku on Exercism|https://exercism.org/tracks/raku>
    =item2 L<Wikipedia|https://en.wikipedia.org/wiki/Raku_(programming_language)>
    =item2 L<empty|#>
    =item2 L<empty|#>
    =item2 L<empty|#>

=end nested
=begin nested :!nested

=item1 B<L<Documentation|/doc>>
    =item2 L<Getting started, Migration guides from other languages, & Tutorials | file:../doc/introduction.podlite>
    =item2 L<Language References|file:../doc/reference.podlite>
    =item2 L<Type Reference| file:../doc/types.podlite>
    =item2 L<Miscellaneous| file:../doc/miscellaneous.podlite>
    =item2 L<FAQs (Frequently Asked Questions)|/doc/language/faq>
    =item2 L<Community|/doc/language/community>
    =item2 L<The list of all documents|file:../doc/index.podlite>

=item1 B<Resources>
    =item2 L<The Raku Guide|https://raku.guide/>
    =item2 L<Books |https://perl6book.com/>
    =item2 L<Rosetta Code | https://www.raku.org/community/rosettacode>

=end nested
=begin nested :!nested

=item1 B<Resoures>
    =item2 L<Download | file:../download/index.podlite>
    =item2 L<empty|#>
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    =item2 L<empty|#>

=item1 B<Learning>
    =item2 L<The Raku Guide|https://raku.guide/>
    =item2 L<Wikibook |https://en.wikibooks.org/wiki/Raku_Programming>
    =item2 L<Books |https://perl6book.com/>
    =item2 L<Rosetta Code | https://www.raku.org/community/rosettacode>
    =item2 L<Learn Raku in Y minutes|https://learnxinyminutes.com/docs/raku/>
    =item2 L<Golfing |https://github.com/AlexDaniel/raku-golf-cheatsheet>
=end nested
=begin nested :!nested

=item1 B<Explore>
    =item2 L<Raku Blog Aggregator|https://planet.raku.org/>
    =item2 L<Rakudo Weekly|https://rakudoweekly.blog/>
    =item2 L<The Weekly Challenge |https://perlweeklychallenge.org/>
    =item2 L<Raku Advent Calendar|https://raku-advent.blog/>
    =item2 L<empty|#>
    =item2 L<empty|#>
    =item2 L<empty|#>
    =item2 L<empty|#>
    =item2 L<empty|#>

=end nested
=end React


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CrossTabulate

Data::Reshapers::CrossTabulate

Synopsis

Data::Reshapers v0.1.9

Authors

License

Dependencies

Test Dependencies

Provides

Documentation