Re: [Gretl-users] pre-allocating matrix

On Thu, 27 Mar 2014, Cottrell, Allin wrote: Having done an experiment I'm actually quite surprised at just how much > faster > option 2 is. Here's my test: > You shuld also consider the "loop" overhead. Try this: <hansl> set echo off set messages off loop i=1..10 --quiet matrix X$i = mnormal(200,20) endloop # option 1 set stopwatch loop 100 --quiet matrix A = X1 ~ X2 ~ X3 ~ X4 ~ X5 ~ X6 ~ X7 ~ X8 ~ X9 ~ X10 endloop t0 = $stopwatch set stopwatch loop 100 --quiet matrix A = {} loop i=1..10 --quiet A = A ~ X$i endloop endloop t1 = $stopwatch print t0 t1 </hansl> ------------------------------------------------------- Riccardo (Jack) Lucchetti Dipartimento di Scienze Economiche e Sociali (DiSES) Università Politecnica delle Marche (formerly known as Università di Ancona) r.lucchetti(a)univpm.it http://www2.econ.univpm.it/servizi/hpp/lucchetti ------------------------------------------------------- _______________________________________________ Gretl-users mailing list Gretl-users(a)lists.wfu.edu http://lists.wfu.edu/mailman/listinfo/gretl-users