Abdel Rahmen El Lahga <[email protected]> wrote,
> Is there any solution to rewrite this fragment of my mata code more
> efficiently. My old laptop runs more then 1 hours without finishing the job
> on 50591 obs.
Abdel then included the Mata code. Abdel has a silly typo in his code and, as
written, his laptop never would have finished. Abdel typed
for (i=1; i=nt; i++) {
...
}
when he meant to type
for (i=1; i<=nt; i++) {
...
}
That is, he typed "i=nt" when he meant "i<=nt".
What the mistaken version did was set i=nt at the start of the loop, increment
i at the bottom of the loop and then, starting the loop again, reset i equal
to nt. Hence, the endless loop. I have written a few such loops myself.
Abdel asked for comments, and I have only one suggesion for him: If he were
to indent his code, and spread it out horizontally, it would be easier to see
what it does, to see how it works, and to spot bugs:
void fe()
{
stata ("drop _all")
stata ("use c:\data\nicolas\select\sas\testing")
y_init = x_init = s_init = .
st_view(y_init, ., "f_week_hours")
st_view(x_init, ., ("f_lnwage", "m_lnwage", "assetinc"))
st_view(s_init, ., "s_init")
tmax = 21 // tmax
n = rows(x_init)/tmax // nombre d'individus
nt= rows(x_init) // nombre total des lignes
k = cols(x_init) // nombre de regresseurs
k
y = J(nt, 1, 0)
x = J(nt, k, 0)
s = s_init
for (i=1; i<=nt; i++) {
if (s[i]=1) {
y[i,.] = y_init[i,.]
x[i,.] = x_init[i,.]
}
}
}
Oops, I just spotted another typo. Abdel typed
if (s[i]=1) {
when he meant to type
if (s[i]==1) {
A single equal sign means assignment. == means equality test.
Typos aside, it is well structured and easily understood code.
-- Bill
[email protected]
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