_ROOT Version: root_v5.34.36 Hi: I’m fitting pion yield w.r.t transverse momentum, but the covariance matrix that I got is identically 0 matrix (7-by-7, for 7 parameters). Then I added the fit option “V”, verbose mode. It tells me call reaches limit: [image] And right below that, we can see …

Hi @Shonlin , I answered in your previous post: [image] Why do I keep getting a zero matrix from TFitResult for some dataset while not the others? ROOT Dear StephanH @StephanH : Thanks. Good news: after using the verbose mode “V”, it returns to me some EXTERNAL ERROR MA…

What should I do if Fit reaches CALL LIMIT and behaves strangely for some dataset I feed?

ROOT

StephanH July 15, 2019, 10:07am 2

Hi @Shonlin,

I answered in your previous post:

Let me know if this works.

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