Dear Amitvikram, Aidyn is correct. If you know an analytic solution, this can be included in the "ExactSolution" function in the session file and most solvers subtract this before computing the L2 integral to give a measure of error. If you do not specify the function, the "L2 error" will just be the integral of the solution over the domain. Linf tells you the pointwise-maximum error in the same way. Cheers, Chris On Wed, 30 Jan 2019 14:22:15 -0500, Aidyn Aitzhan <aidyn.b.aitzhan@gmail.com> wrote:

Hello,

...

From my observations, nektar++ compares solution with 0, if you are not specifying the exact solution. Please correct me if I'm wrong.

Aidyn

On Wed, Jan 30, 2019, 09:17 Amitvikram Dutta <amitvdutta23@gmail.com wrote:

...

Hi all,

I'd like to clear up a point that has been bugging me for some time. Are the L2 and Linf norms in nektar++ always defined with respect to a given analytical solution for a problem? What do these terms represent in a case for which a solution is not specified?

Sincerely, --

*Amitvikram Dutta*

Graduate Research Assistant

Fluid Mechanics Research Lab

Multi-Physics Interaction Lab

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-- Chris Cantwell Imperial College London South Kensington Campus London SW7 2AZ Email: c.cantwell@imperial.ac.uk www.imperial.ac.uk/people/c.cantwell