Dear Desmos folks,
I’m trying to have a graph which shows what the student enters into a math box, but which doesn’t go completely blank when the mathbox entry is half-typed and hence undefined.
I’ve trying variations of the CL below, but none of them seem to work:
when isUndefined(“f”) simpleFunction(“y=x”)
I think I’m not giving simpleFunction the correct input. Some other inputs that don’t work: x with backticks around it, “x” with quotes around it. In all cases, the function f simply disappears when the input box is half-formed, rather than defaulting to showing an actual line rather than just an empty graph.
Any help greatly appreciated,
f can’t really be defined in terms of itself, so you want to apply
isUndefined to the LaTeX instead. To avoid repetition, I’d go with something like:
when isUndefined(input) simpleFunction("x")
Thanks for the suggestion!
You raise a very valid point about making sure that the definition of f doesn’t mention itself. That said, the solution that you posted doesn’t work for me. Here is a minimal example:
It starts off with a malformed input, saying “x^2 +”, and the graph is blank, despite the attempt to provide a default function of x. Nothing shows up until you type something after the + sign, e.g. x^2 + 1
Apologies, I made an error in the code I gave you. It should have said:
function(`f`): when isUndefined(input) simpleFunction("x") otherwise input
(You could also just replace
simpleFunction(input) in the original code, but I like to get into the habit of using variables for anything I am going to use more than once).
Thanks! Your change of wrapping simpleFunction around the input1.latex part fixed it for me.
Thanks again for all your help,