@error Basis factorization failed, Insufficient workspace(3)

[devansh agrawal]

I am using APOPT solver. My model is running fine for the small sample problem. But it is showing the following error for the larger dataset.

Basis factorization failed Info -7

 Insufficient workspace(3)

[John Hedengren]

Devansh,

If you are running in IMODE=4 then a simple thing to do is to try IMODE=7. It will be a much smaller version of your problem because it processes the data sequentially instead of simultaneously.

Another option is to switch to one of the other solvers such as BPOPT or IPOPT with m.options.SOLVER = 2 or =3. Do you require APOPT to solve your problem?

If you can post your issue to StackOverflow (with tag gekko), the question and answer will help more people as well. Please consider posting a Minimal, Verifiable code that demonstrates the problem that you are having: https://stackoverflow.com/help/minimal-reproducible-example

Best regards,

John Hedengren

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Best regards,

John Hedengren

GEKKO Optimization Suite

https://machinelearning.byu.edu

[devansh agrawal]

Thanks Prof. John for your prompt reply.

I am using IMODE=6 and i have tried IPOPT solver too. i have attached the screenshot of the error. i am not able to figure out, is it suggesting me to change the MUMPS?

On Wednesday, April 29, 2020 at 9:46:09 PM UTC-4, John Hedengren wrote:

Devansh,

If you are running in IMODE=4 then a simple thing to do is to try IMODE=7. It will be a much smaller version of your problem because it processes the data sequentially instead of simultaneously.

Another option is to switch to one of the other solvers such as BPOPT or IPOPT with m.options.SOLVER = 2 or =3. Do you require APOPT to solve your problem?

If you can post your issue to StackOverflow (with tag gekko), the question and answer will help more people as well. Please consider posting a Minimal, Verifiable code that demonstrates the problem that you are having: https://stackoverflow.com/help/minimal-reproducible-example

Best regards,

John Hedengren

On Wed, Apr 29, 2020 at 7:41 PM devansh agrawal <devansh.a...@gmail.com> wrote:

I am using APOPT solver. My model is running fine for the small sample problem. But it is showing the following error for the larger dataset.

Basis factorization failed Info -7

 Insufficient workspace(3)

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[John Hedengren]

Devansh,

How many data points are there? You may want to find a way to condense your data or else use a shooting method for optimization instead of a simultaneous method. There is more discussion on the difference in approaches here: https://en.wikipedia.org/wiki/Trajectory_optimization  I saw from one of your other notes that you are working on COVID-19 simulations. Here are some example files for optimizing the curve: https://apmonitor.com/do/index.php/Main/COVID-19Response

If it is a simulation (no degrees of freedom) then IMODE=7 should work better for you.

Best regards,

John Hedengren

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