Re: Obtaining terms in an expansion

[trammell]

Does this do what you want?

my $n = $ARGV[0] || 5;
my @terms = qw( a[0][0] a[0][1] );
foreach my $i (1 .. $n-1) {
    @terms = map { ("$_ a[$i][0]","$_ a[$i][1]") } @terms;
}   
foreach my $i (0 .. $#terms) {
    print "term[$i] = $terms[$i]\n";
}

Update: fixed off-by-one error

[runrig]

You have N terms going in, and N terms coming out. He says in the OP that he wants 2^N expressions returned. This is considered 2 terms, so there are 4 expressions returned.

Update: my mistake. Did not read carefully enough.

[trammell]

That's funny, because when I run the program for N=2, I get:

term[0] = a[0][0] a[1][0] a[2][0]
term[1] = a[0][0] a[1][0] a[2][1]
term[2] = a[0][0] a[1][1] a[2][0]
term[3] = a[0][0] a[1][1] a[2][1]
term[4] = a[0][1] a[1][0] a[2][0]
term[5] = a[0][1] a[1][0] a[2][1]
term[6] = a[0][1] a[1][1] a[2][0]
term[7] = a[0][1] a[1][1] a[2][1]

So perhaps I have an off-by-one error, but certainly I'm generating 2^N terms.