How to set lower limit on parameter in TF1

Dear ROOT Support,

I would like to place a lower limit on a parameter in my function, while leaving the upper limit free. Is this possible?

The formula for my function is:
TFormula mypol4(“mypol4”,"[0] * ( 1 + [1]*x + [2]*x^2 + [3]*x^3 + [4]*x^4 )");

I would like to set limit so that the parameter [0] is not negative.

Thanks very much.

Best wishes
Teh Lee

You can specify the lower and upper limit, but not only one of them.
You can always specify a large value and tune it in a second pass when you get an approximate answer.


Many thanks for your answer.

Best wishes,
Teh Lee