Getting the Y value from a TF2 for a given X and Z

ROOT
1

Dear rooters,

I have a TF2 resulted from a fit to a TGraph2D. From that TF2 I would like to get, for a given X, the value of the Y for a given function value.

For a TF1 I usually get the roots of a function calling the TF1->GetX(py).

Could please someone let me know if there is a similar method for calculating one of the variables of a TF2 for a given value of the function?

Many thanks.

Best regards,

Jorge

2

Dear Jorge,

TF2 does not seem to have such functionality. A possible solution is to derive a TF1 where one of the arguments (X) is fixed, and then use GetX on the derived TF1.
If you are on Root 6, you can use a lambda function to that.
See for example root.cern.ch/doc/master/classTF1.html#F5 .

G Ganis