Perl科学计算(1.2)

Perl科学计算(1.2)

#分布函数
my @ex8=(1,9,4,9,10,12,13,15,12,13);
my %hash=&frequency(\@ex8);
print join(",",values %hash);
print join(",",keys %hash);

sub frequency{
    my($vec)=@_;
    my %hash;
    foreach(@$vec){
        ++$hash{$_};
    }
    return %hash;
}

#排序函数
my @ex9=(1,9,4,9,10,12,13,15,12,13);
print  join(',',&sortf("numeric","asc",\@ex9));

sub sortf{
    my($type,$direction,$vec)=@_;
    my @vec_sort;
    if(($type eq "numeric") & ($direction eq "asc")){
        @vec_sort=sort{$a<=>$b}@$vec;
    }
    if(($type eq "numeric") & ($direction eq "desc")){
        @vec_sort=sort{$b<=>$a}@$vec;
    }
    if(($type eq "string") & ($direction eq "asc")){
        @vec_sort=sort{$a cmp $b}@$vec;
    }
    if(($type eq "string") & ($direction eq "desc")){
        @vec_sort=sort{$b cmp $a}@$vec;
    }
    return @vec_sort;
}

#众数
my @ex10=(1,9,4,9,10,12,13,15,12,13);
print join(',',&mode(\@ex10));

sub mode{
    my($vec)=@_;
    my %hash=&frequency($vec);
    my @result;
    foreach(sort{ $hash{$b}<=>$hash{$a} }  keys %hash){
        last if @result && $hash{$_} != $hash{$result[0]};
        push(@result,$_);
    }
            return @result; 
}

#中位数
my @ex111=(1,9,4,5);
print &median(\@ex11);
my @ex112=(1,9,4,5,5);

sub median{
    my($vec)=@_;
    my @vec1=&sortf('numeric','asc',$vec);
    my $length=scalar @$vec;
    my $result;
    if($length % 2){
        $result=$vec1[($length-1)/2];
    }else{
        $result=($vec1[$length/2]+$vec1[$length/2-1])/2;
        }
    return $result;
}

#四分之一分位数

 my @ex12=( 7, 15, 36, 39, 40, 41);
print join(',',&quantile(\@ex12));

sub quantile{
    my($vec)=@_;
    my @vec1=&sortf('numeric','asc',$vec);
    my $length=scalar @$vec+1;
    my($upper,$lower);
    if($length %4 ){
        my $temp1=int($length/4);
        my $temp2=int(3*$length/4);
        $upper=$vec1[$temp1-1]+($vec1[$temp1]-$vec1[$temp1-1])*($length/4-$temp1);
        $lower=$vec1[$temp2-1]+($vec1[$temp2]-$vec1[$temp2-1])*(3*$length/4-$temp2);
        }else{
            $upper=$vec1[$length/4-1];
            $lower=$vec1[3*$length/4-1];
        }
        my @result=($upper,$lower);
        return @result; 
    }

#最大值
my @ex13=( 7, 15, 36, 39, 40, 41);
print &max(\@ex13);

sub max{
    my($vec)=@_;
    my @result=&sortf('numeric','desc',$vec);
    return $result[0];
}

#最小值
my @ex14=( 7, 15, 36, 39, 40, 41);
print &min(\@ex14);

sub min{
    my($vec)=@_;
    my @result=&sortf('numeric','asc',$vec);
    return $result[0];
};
#标准化，共2种方法
my @ex15=( 7, 15, 36, 39, 40, 41);
print join(',',&scale(\@ex15,2));

sub scale{
        my($vec,$m)=@_;
        my @result;
        if($m eq 1){
            if(&max($vec) eq &min($vec)){
                die "could not scale as range method!";
            }else{
                @result=map(($_-&min($vec))/(&max($vec)-&min($vec)),@$vec);
                }
           return @result;
           }
           if($m eq  2){
               if(&var($vec) eq 0){
                die "could not scale as centered method!";
               }else{    
                    @result=map(($_-&mean($vec))/&sd($vec),@$vec);           
                   }
               return @result;
              }
}