excel linear 2d interpolation with data incapsulation demo

#!/usr/bin/perl

my $ip_preg = 'interp\(([^;]+);([^;]+);([^;]+);([^;]+);([^;]+)\)';
my $ip_repl = '"И($1>=$2;$1<$3)*(($1-$2)/($3-$2)*($5-$4)+$4)"';

my @xi = (1,2,2,3,3,4);
my @yi = (0,0,1,3,3,2);
my $exp = '';

for (my $i = 0; $i < 6; $i += 2) {
        $exp = $exp . "interp(A1;" . $xi[$i] . ';' . $xi[$i+1] . ';' . $yi[$i] . ';' . $yi[$i+1] . ')+';

}

$exp =~ s/$ip_preg/$ip_repl/gee;
print $exp;