fractional_ranking.raku

my @vals= <1 2 40 40 90 20.5 20.5 20.5 20.5 4 4 6>;
my @new = @vals.BagHash.sort(+*.key);
my $i=1;
for @new {
    if .value == 1 {
        say .key => $i; 
        $i+=1
        } else {
            say .key => $i+(.value - 1)/2;
            $i = $i + .value
        }
}

for @vals {
    $_ = %damn{$_}
    }

lucas_number.raku

#Recursive solutions 

#1st 

sub lucas_number(Int $nth) {
    given $nth {
        when 0 { 2 };
        when 1 { 1 };
        default {lucas_number($nth-1) + lucas_number($nth-2)}
    }
}

say lucas_number(20)

#2nd recursive solution


multi lucas_number(0) {2};
multi lucas_number(1) {1};
multi lucas_number(Int $nth) {
    lucas_number($nth - 1) + lucas_number($nth - 2)
}

say lucas_number(20)



# Fastest solution 


multi lucas_number(0) {2};
multi lucas_number(1) {1};
multi lucas_number(Int $nth where * > 1) {
    my @array = <2 1>;
    my $i = 1;
    while $i < $nth {
        @array.push(@array[$i] + @array[$i-1]);
        $i = $i + 1
    }
    @array[$i]
}


say lucas_number(3500)




# Suggested by lizmat


my @lucas = 0, 1, * + * ... *;
for 1..20 {say @lucas[$_]};

say @lucas[3500]

multiple_files.raku

for 1..3 {say "Bio",$_,".jpg"};
.say for "Bio" <<~<< (1..3) >>~>> ".jpg";
"Bio$($_).jpg".say for 1..3;
.fmt("Bio%d.jpg").say for 1..3;
<Bio .jpg>.join((1..3).join(".jpg\nBio")).say;
say ("Bio1.jpg", *.succ ... *).head(3);
say  "Bio" xx 3 Z~ 1..3 Z~ ".jpg" xx 3;
say [Z~] "Bio" xx 3, 1..3, ".jpg" xx 3;
say (S/ℵ/$(1..$++)/ given "Bioℵ.jpg") xx 3;

script.raku

# script to list files in a directory matching a file extension 
# Main function takes two parameters: folder and a file extension pattern

sub MAIN($folder, $pattern) {
    if $folder.IO.d {
        # if folder is a directory
        for $folder.IO.dir -> $filename {
            say $filename if $filename.IO.f && $filename ~~ /:i $pattern$/;
            # if filename matches the file extension and the filename is a file
        }
    }
}

#******************************************
# Usage:

# raku script.raku <folder> <extension>

#******************************************

softmax.raku

# softmax function


my @z = [1.0, 2.0, 3.0, 4.0, 1.0, 2.0, 3.0];


sub softmax(@val,$beta) {
    my @beta_into_n = @val.map: {exp($_*$beta)};
    return @val.map: {exp($_)/sum(@beta_into_n)}
}

say softmax(@z,1)

sorting_hash_keys.raku

#Sorting keys as Integer in Hash

my %my_hash is Hash[Int, Int] = 9 => 3, 12 => 5, 5 => 7, 3 => 11, 11 => 13;  
for %my_hash.sort -> (:$key, :$value) {   
    say "'$key' => '$value'"; 
    }



my %my_hash = 9 => 3, 12 => 5, 5 => 7, 3 => 11, 11 => 13; 
for %my_hash.sort(+*.key) -> (:$key, :$value) {   
    say "'$key' => '$value'";
    }

write-csv.raku

srand(1);
my @test1 = [6,6,4,6,8,6,8,4,4,6,6,8,8,8,8,8,8,4,4,4,4,8,8,8,8,4,4,4,8,6,8,4];
my @test2 = [160.0,160.0,108.0,258.0,360.0,225.0,360.0,146.7,140.8,167.6,167.6,
            275.8,275.8,275.8,472.0,460.0,440.0,78.7,75.7,71.1,120.1,318.0,304.0,
            350.0,400.0,79.0,120.3,95.1,351.0,145.0,301.0,121.0];

my @test3 = @test1.roll(10);
my @test4 = @test2.roll(10);
my @test5 = @test1.roll(10);

# write csv 
my $fh = 'my-file.csv'.IO.open: :w;
$fh.print: "car, mileage, numbers"; # headers
for @test3 Z @test4 Z @test5 {
   $fh.print: "\n", $_.join(", ");    
}
$fh.close;

writecsv_function.raku

my @test1 = [6,6,4,6,8,6,8,4,4,6,6,8,8,8,8,8,8,4,4,4,4,8,8,8,8,4,4,4,8,6,8,4];
my @test2 = [160.0,160.0,108.0,258.0,360.0,225.0,360.0,146.7,140.8,167.6,167.6,
            275.8,275.8,275.8,472.0,460.0,440.0,78.7,75.7,71.1,120.1,318.0,304.0,
            350.0,400.0,79.0,120.3,95.1,351.0,145.0,301.0,121.0];


# write csv 
# columns are variables

sub write_csv($filename, List :$columns, List :$headers) {
    # checking 
    die "Provide csv file" if $filename !~~ /\.csv$/;
    #$headers;
    die "Provide equal number of headers and columns" if 
        $columns.elems != $headers.elems;
    my $fh = $filename.IO.open: :w;
    $fh.print: $headers.join(", "); # headers
    for [Z] $columns {
        $fh.print: "\n", $_.join(", ");    
    }   
    $fh.close;
}

write_csv("my-file.csv", columns=>(@test1, @test2), headers=>("car", "mile"));