use YAML qw( DumpFile );

my @data = (
    [
        {
            "title" => "line 1", 
            "style" => "lines" , 
            "type" => "matrix"
        }, 
        [ 1, 6318 ], 
        [ 2, 7903 ], 
        [ 3, 25617 ], 
    ],
    [
        { 
            "title" => "line 2", 
            "style" => "lines" , 
            "type" => "matrix"
        }, 
        [ 1, 6215 ], 
        [ 2, 7831 ], 
        [ 3, 25782 ],
    ],
);

DumpFile( "output.txt", @data )