/ 
SimpleR-Reshape-0.06
River stage one • 2 direct dependents • 2 total dependents
/ SimpleR::Reshape

NAME

SimpleR::Reshape 数据处理转换

接口山寨自R语言的read.table/write.table/merge，还有reshape2、dplyr

FUNCTION

实例参考xt子文件夹

read_table

支持 从文件或arrayref 按行读入数据，转换后输出新的 文件或arrayref

my $r = read_table(
    'reshape_src.csv', 
    skip_head=>1, 
    conv_sub => sub { [ "$_[0][0] $_[0][1]", $_[0][2], $_[0][3] ] }, 

    write_file => '01.read_table.csv', 
    #skip_sub => sub { $_[0][3]<200 }, 
    #return_arrayref => 1, 
    #write_head => [ "head_a", "key" , "value" ], 
    #sep=>',', 
    #charset=>'utf8', 
);

write_table

将指定数据写入文本文件

my $d = [ [qw/a b 1/], [qw/c d 2/] ]; 
write_table($d, 
    file=> 'write_table.csv', 
    head => [ 'ka', 'kb', 'cnt'], 
    #sep => ',', 
    #charset => 'utf8', 
);

melt

数据调整，参考R语言的reshape2包

#id => [1, 2, 3], 'somekey', sub { ... }
#measure => [4,5,6, ...]

my $r = melt('reshape_src.csv',
    skip_head => 1, 

    names => [ qw/day hour state cnt rank/ ], 

    #skip_sub => sub { $_[0][3]<1000 }, 
    id => [ 0, 1, 2 ],
    measure => [3, 4], 
    melt_file => '02.melt.csv',
    #return_arrayref => 0, 
);

cast

数据重组，参考R语言的reshape2包

注意：

reduce_sub 是在读取数据的过程中处理value，默认是直接push到value列表里

stat_sub 是在数据读取完毕后，对value列表进行最终统计处理

id => 与melt同

measure => return 1 value，取值类似1,2,3,4

value => return 1 value，取值类似1,2,3,4

my $r = cast('02.melt.csv', 
    cast_file => '03.cast.csv', 
    #return_arrayref => 0, 
    #write_head => 0, 

    #key 有 cnt / rank 两种
    names => [ qw/day hour state key value/ ], 
    id => [ 0, 1, 2 ],
    measure => 3, 
    value => 4, 

    result_names => [ qw/day hour state cnt rank/ ], 

    #default_cell_value => 0,

    stat_sub => sub { my ($vlist) = @_; my @temp = sort { $b <=> $a } @$vlist; return $temp[0] }, 

    #reduce_sub => sub { 
    #   my ($r) = @_;
    #   my $s=0 ; $s+= $_ for @$r; 
    #   return [ $s ];
    #   }, 
);

merge

合并两个dataframe，在perl中是二层数组

my $r = merge( 
    [ [qw/a b 1/], [qw/c d 2/] ], 
    [ [qw/a b 3/], [qw/c d 4/] ], 
    by => [ 0, 1], 
    value => [2], 
);
# $r = [["a", "b", 1, 3], ["c", "d", 2, 4]]

split_file

把一个大文件按指定id或行数拆分成多个小文件

my $src_file = '06.split_file.log';

split_file($src_file, id => [ 0 ] ,
    # sep => ',', 
    # split_file => '06.test.log', 
);

split_file($src_file, line_cnt => 400);

arrange

sort rows by some method

按指定方法，将所有数据按行重新排序

my $r = arrange('reshape_src.csv', 
    skip_head => 1, 
    sep=> ',', 
    charset => 'utf8', 

    arrange_sub => sub { 
        $a->[4] <=> $b->[4] or
        $a->[3] <=> $b->[3] 
    }, 
    arrange_file => '07.arrange.csv', 
    return_arrayref => 1, 
    write_head => [ qw/day hour state cnt rank/ ], 
);