if command in loop procedure.

[ha lee]

I'm trying to use if command in loop procedure. But I got the message " 'if' found where almost anything else expected" whenever I use if- command .

The code that I wrote is presented below.



kmat=J(10,3,1)
N=rows(kmat)

for (i=1; i<=N;i++) {
tmp1=0
for (j=1; j<=N; j+++ {
if ([j]!=[i]) {
tmp1 = tmp1 + (2*Kmat[i,j])
}
}
}

And I got the error message('if' found where almost anything else expected") when if command is presented.

What's the wrong with this code?

[Christophe Kolodziejczyk]

ha lee parenthesis missing at the end of for (j=1..., this is what triggers the error message...and it should be (for example)

for (j = 1 ; j<= cols(kmat); j++) // kmat has only 3 columns not N

you don't need the brackets in the if condition, so it should be

if (i!=j)

and

tmp1 = tmp1 + (2*kmat[i,j]) // not Kmat

[Ana Siqueira]

Hi, good evening.

I have a sample of 10 industries and 20 years and I need to run the regression in looping by industry (for one model) and by year (for another model) and create a new variable with the residuals (for one model) and the coefficient (for another model) of the regression.

Can anyone help me with that?

Thanks

Ana Siqueira

[Sergio Correia]

If what you want is the residuals, just run that model with reghdfe 4.x:

sysuse auto, clear

reghdfe price, absorb(foreign##c.(gear length)) residuals(resid1)

* Check that it works
reg price gear length if foreign==0
predict double resid2a, resid
reg price gear length if foreign==1
predict double resid2b, resid
clonevar resid2 = resid2a
replace resid2 = resid2b if foreign==1

su resid1 resid2
corr resid1 resid2

Edit: TBH you don't particularly need reghdfe, you can run this with any regress command:

reg price foreign##c.(gear length)

[Pablo Bonilla]

Ha Lee, You're missing a ")" in your second loop.

Best,