inverse in OM

[shabunin_a@…]

Hello.

How I can realize this function:
x = y², but (-y)² = -x, sqrt(-x) = -y.

My attempt to make this function in file.

[Francesco Casella]

I had a look on your example, using OMEdit and the Transformational Debugger.

Point 1, as far as I know, the inverse annotation is still not supported by OMC, so it will just ignored.

Point 2: the Inline annotation has a capital "I", if you write annotation(inline = false))] it will simply be ignored.

Point 3: if you don't put an Inline = false annotation in function x_to_y, the backend somehow tries to inline it and solve it explicitly, but doesn't do it correctly:

(assign) $TMP$VAR$1$0X$ABS := pre(x)
(assign) x := $_signNoNull($TMP$VAR$1$0X$ABS) * abs(y ^ 0.5)

So, a simple solution to your problem is just to add annotation(Inline = false) in x_to_y

@ptaeuber, can you have a look at the wrong solution of the inverse function?

[Patrick Täuber]

There was a bug in the variable replacements. After fixing it in ​OMCompiler/c22c35b the equation cannot be solved explicitly anymore, thus the results are now correct.

[Francesco Casella]

shabunin_a@…, please check and close the ticket if everything is fine for you after this fix.

[Martin Sjölund]

I assume it's fixed and will close this.