How do i set the default simulation run length to be less than 10S

Cylc Cylc 8 Migration
1

hey,

i’m doing some simulation mode runs and want to change the default run length to be less than the default 10 seconds. i know this is possible because it’s described in the docs (here and here) but i am having trouble interpreting exactly what i am supposed to change.

i’ve tried the two things in the screenshots but they both fail.

i appreciate this is simply a case of me not knowing how to read the docs properly so hopefully i can learn something here! for example, in this syntax…

flow.cylc[runtime][<namespace>][simulation]default run length

what exactly does [<namespace>] refer to?

let’s say i have a workflow with like (probably wrong syntax but you get the idea)…

R1 = foo => bar
PT1M => foo[-PT1M]

does [<namespace>] refer to foo and bar respectively? or can i set a global new simulation time of, say, 2s?

thanks for any tips and tricks as per usual!

j

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2

The single-line shorthand notation:

[runtime][<namespace>]blah...

corresponds to this in the flow.cylc format:

[runtime]
    [[<namespace>]]
        blah...

So <namespace> can be any task or family name (including root if you want to set the simulated run-length for all tasks at once).

For future reference, it’s defined in the config reference section of the docs:

(It’s called a “namespace” for somewhat valid technical reasons, and to avoid having to say “task or family name” all the time).

1 Like
3

Yes, you can do this like so

[runtime]
    [[root]]
        [[[simulation]]]
            default run length = PT2S

The root namespace in Cylc is a special one that all tasks inherit from.

(Edit: just noticed Hilary already mentioned it, but anyway there’s an explicit example)

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4

thanks a lot @hilary.j.oliver, now i understand the setup of the namespace syntax thing better and the example provided @MetRonnie works perfectly, brilliant!

i think what was confusing me was that the shorthand only had single [...] in it whereas what i needed was some [[...]]!

anyway, sorted now, much apprecaited.

j

5

Yeah, the problem is the number of brackets gets ridiculous for deep nesting.

Documented here: The .cylc File Format — Cylc 8.2.2 documentation

1 Like