# G0121 : Matrix not positive definite [actest.gss, line 498

Hi! I encounter this problem while running an asymmetric causality test on a negative partial sum. results of the positive partial sum are correct but how do I run the causality test on negative partials. I will be very grateful if anybody helps me to resolve the issue.

G0121 : Matrix not positive definite [actest.gss, line 498

gauss is showing this kind of error

0

What is the line of code that causes the error?

Most likely the line contains a call to either `inv` or `invpd`. For example:

``b = invpd(X'X)*X'y;``

If that is the case, right before that line add these statements:

``````print "X = " X;
print "X'X = " X'X;``````

This problem could be because your data was not loaded as expected. If you see more than one line of constant values, that would cause this problem.

0

hello! thanks for your assistance but now gauss is showing an error inline 2

G0025: undefined symbol 'x'[actest.gss, line2]

0

What was the line of code on line 498 of actest.gss?

0

currently active call:

file actest.gss, line 498, in lag_lengh2,

Ahat = (y/x)';

this is the message of error

0

Right before line 498, you need to add the print statements. So line 498 will stay the same but the lines immediately above them will be different. It should look like this:

```GAUSS
print "y = " y;
print "x = " x;
Ahat = (y/x)';
```

0

Right before line 498, you need to add the print statements. So line 498 will stay the same but the lines immediately above them will be different. It should look like this:

``````print "y = " y;
print "x = " x;
Ahat = (y/x)';``````

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