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Hanyu
Fluorite | Level 6

I want to estimate a ARFIMA model of realised volatility using real series (not simulated ones) . Here is my code.

proc iml;

use square;

read var{square}into exper ;

lag=(0:5);

d=0.4;

phi=0.5;

ma=0.3;

sigma=0.06;

call farmafit(d,phi,ma,sigma,exper);

Sas generate a error saying insufficient number of observations. I have 787 observation for this time series.

Anybody know why? Thank you in advance.

1 ACCEPTED SOLUTION

Accepted Solutions
Rick_SAS
SAS Super FREQ

My guess is that you don't have 787 observations. You have 1 (which is certainly insufficient). Print the number of rows for expe like thisr:

print "number of rows=" (nrow(exper));

You might also try the following example and report what happens:

proc iml;

use sashelp.air;

read all var{air} into exper;

close sashelp.air;

call farmafit(d,phi,ma,sigma,exper);

print d, phi, ma, sigma;

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5 REPLIES 5
Rick_SAS
SAS Super FREQ

My guess is that you don't have 787 observations. You have 1 (which is certainly insufficient). Print the number of rows for expe like thisr:

print "number of rows=" (nrow(exper));

You might also try the following example and report what happens:

proc iml;

use sashelp.air;

read all var{air} into exper;

close sashelp.air;

call farmafit(d,phi,ma,sigma,exper);

print d, phi, ma, sigma;

Hanyu
Fluorite | Level 6

Thank you for your response. I have tried print "number of rows=" (nrow(exper)); using sashelp.air;

The return number is 144. The estimation of the ARFIMA on sashelp.air reports d=1.15 phi ma don't exist. sigma=1118.

Rick_SAS
SAS Super FREQ

I meant for you to print the number of rows for your example, not for mine.

Hanyu
Fluorite | Level 6

I will post it tomorrow if that is okay for you as it is pretty late in UK.

Hanyu
Fluorite | Level 6

Thank you so much Rick. I have solved my issue. Unfortunately there is no long memory feature of my series.

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