Adding asin / "configuration is invalid" error

[benlabbeus]

Hi sorry for the repeat questions, a bit new to this.

I'm trying to add asin as a unary operator, I have the following:

unary_operators=["cos", "sin", "asin(x)=asin(x)", "tan", "atan", "abs", "sqrt"],
extra_sympy_mappings={"atan2": lambda x, y: sympy.atan(x,y),
                          "asin": lambda x: sympy.asin(x)},

And I'm getting the error

Your configuration is invalid - one of your operators (asin) is not well-defined over the real line. You can get around this by returning NaN for invalid inputs.

Should I be defining the unary operator like this?

unary_operators=["cos", "sin", "asin(x)=x", "tan", "atan", "abs", "sqrt"],

[MilesCranmer]

You are almost there. Since asin is not valid for abs(x)>1, you need to create a new operator that either (1) clips the input to be valid, or (2) returns a NaN for invalid input.

I generally prefer (2) as the output equations won't have weird steps in them. You could do this:

"my_asin(x) = abs(x) > 1 ? convert(typeof(x), NaN) : asin(x)"

and then just give it the normal sympy definition by for "my_asin" instead.

[benlabbeus]

Awesome!! We're rolling! Thank you!!