Test models and Julia builder for pysd

[rogersamso]

Hi!

I see that you are trying to implement Vensim and Stella functions, an I thought you'd be interested to know about this repo, to verify your implementations.

Also, I've been thinking about having a Julia builder for pysd for a long time (check this out), and your work looks like an excellent starting point!

I'll keep an eye on your progress, and try to contribute soon.

Cheers

[natema]

Thanks Roger for contacting us!
We have indeed already interacted with PySD, especially regarding the Vensim DELAY function: see SDXorg/pysd#391 and #183.
As we point out in #183, the Vensim implementation of DELAYN is still unclear to us in some cases. Our implementation matches the one in Stella, so we hope the bug is on Vensim's side.