Re: [Gretl-users] foreach vs for with list
On Fri, 15 Dec 2017, Schaff, Frederik wrote:
Hi there, I'd expect both options to be equivalent (add a matrix
with the data from the series to the array of matrices). However,
the forach loop only adds the first data-point to the matrix.
<hansl>
open denmark.gdt -q
list ls = 1 4
matrices M = null
loop foreach l ls
matrix temp = l
colnames(temp,varname(l))
M+=temp
endloop
matrices M2 = null
loop s=1..nelem(ls)
matrix temp = ls[s]
colnames(temp,varname(ls[s]))
M2 += temp
endloop
In your first loop, 'l' is a just scalar index, so
matrix temp = l
gives you {1} on the first iteration and {2} on the second. If you
want to access the series at position l in the list you need to say
matrix temp = $l
Then you'll get the same output as from your second loop.
Allin