A quick follow-up with another error.

 

As part of trying to figure out the initial error, I moved the nulldata command inside the first loop and got an error saying it’s not available in loop mode. Ok, but moving ‘nulldata’ back to where it initially was now results in the same error (ie, gretl still thinks nulldata is inside the first loop). Closing the script  & reopening doesn’t help.

 

PS

 


From: gretl-users-bounces@lists.wfu.edu [mailto:gretl-users-bounces@lists.wfu.edu] On Behalf Of Summers, Peter
Sent: Tuesday, February 02, 2010 1:25 PM
To: Gretl list
Subject: [Gretl-users] scalar in loop condition

 

Hi folks,

 

The following has me at a complete loss. This script runs fine:

 

\begin{script}

# program to perform calculations in problem 1.2 of Davidson & MacKinnon

 

nlist = {10; 100; 1000; 10000}

n = rows(nlist)

means = zeros(n,2)

 

loop i=1..n --quiet

    jnk1 = cauchy(nlist[i])

    jnk2 = mnormal(nlist[i],1)

    means[i,] = {meanc(jnk1), meanc(jnk2)}

endloop

 

print means

\end{script}

(“Cauchy” is a function I wrote – see attached).

 

However, when I try to run the following one, I get an error saying “undefined variable nreps in loop condition”. This happens even though the script output says “generated scalar nreps = 1:”

 

\begin{script}

n = 25; # sample size

nreps = 1; # number of replications

 

beta1 = 1;

beta2 = 0.8; # true values of parameters

 

b1 = 0;

b2 = 0;

 

nulldata n

 

loop ii=1..nreps

    # simulate data

    series y = zeros(n,1)

    series u = normal()

 

    #y[1] = beta1 + u[1]

 

    loop jj=2..n --quiet

        y[jj] = beta1 + beta2[jj-1] + u[jj]

    endloop

 

    series y1 = y(-1)

 

    # run regression

    ols y 0 y1

    b1 = b1 + $coeff(1)

    b2 = b2 + $coeff(2)

print b1 b2

endloop

\end{script}

 

I’ve attached both scripts. Note that I’ve just started on ETM_3_1, so there may well be other errors (still getting used to gretl scripts). I can’t for the life of me figure out why either both work or both don’t run. I’m using gretl 1.8.7 on WinXP.

 

TIA,

 

PS

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Dr. Peter Summers

Assistant Professor

Department of Economics

Texas Tech University

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