Populating a vector

gu has asked for the wisdom of the Perl Monks concerning the following question:

Hi monks

Somewhere in a code, I want to populate a (n+1)-vector with one 1 (at the beginning) and then n 0's, like (1, 0, 0, 0).

The first snippet I came with is this ugly unperlish code :

my @poly1_coeffs = () ;
push @poly1_coeffs, 1 ;
foreach (1..$n)
{
    push @poly1_coeffs, 0 ;
}
[download]

Then I became a little more enlightened and wrote

my @poly_coeffs = (0) x ($n + 1) ;
$poly_coeffs[0]++ ;
[download]

Do you see something else/shorter/better ?

Update : I'm dumb.

Thank you, monks.

Gu

Comment on Populating a vector Select or Download Code

Replies are listed 'Best First'.
Re: Populating a vector by jdporter (Paladin) on Dec 15, 2005 at 17:18 UTC
`@poly1_coeffs = ( 1, (0) x $n );` [download] We're building the house of the future together.	[reply] [d/l]
Re^2: Populating a vector by gu (Beadle) on Dec 15, 2005 at 17:19 UTC
/me bangs his head on the first wall he finds. Thanks :) Gu	[reply]
Re: Populating a vector by bageler (Hermit) on Dec 15, 2005 at 17:56 UTC
You could use a real bitvector instead of a memory hungry array: `use PDL; $n = 50; $vec = zeroes ($n+1); index($vec,0) .= 1;` [download]	[reply] [d/l]
Re^2: Populating a vector by thor (Priest) on Dec 15, 2005 at 18:03 UTC
Assuming that his vectors contain only bits... thor `The only easy day was yesterday`	[reply]
Re^3: Populating a vector by bageler (Hermit) on Dec 15, 2005 at 18:18 UTC
You can put values other than 0 and 1 in PDL vectors and it's still less memory intensive than arrays	[reply]
Re^4: Populating a vector by thor (Priest) on Dec 15, 2005 at 19:08 UTC
Re: Populating a vector by blazar (Canon) on Dec 15, 2005 at 18:06 UTC
`my @poly_coeffs = (0) x ($n + 1) ; $poly_coeffs[0]++ ;` [download] Do you see something else/shorter/better ? shorter? `my @poly_coeffs = map !$_+0, 0..$n;` [download] better? (and even shorter) `my @poly_coeffs = (1, (0) x $n);` [download] but I just had to include a map based solution... ;-)	[reply] [d/l] [select]


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