Histograms containing NaN can't be drawn.

@hageboeck

When NaN ends up in a histogram, you can't draw it. This should not stop us from fixing the TTreeFormula issue. Instead, we should devise a strategy to draw the histogram as best as we can, and putting a placeholder into the bins that contain NaN.

Originally posted by @hageboeck in #22756 (comment)

root [0] TH1D histo("histo", "histo", 10, 0, 10);
root [2] histo.SetBinContent(1, std::sqrt(-1));
root [3] histo.Fill(3)
root [4] histo.Draw()
Info in <TCanvas::MakeDefCanvas>:  created default TCanvas with name c1
Warning in <TCanvas::ResizePad>: Inf/NaN propagated to the pad. Check drawn objects.
Warning in <TCanvas::ResizePad>: c1 height changed from 0 to 10

putting a placeholder into the bins that contain NaN.

Related discussion, it seems that with TTree Draw it works fine and the NaNs end up in the overflow bin #22756 (comment) but not with histograms where the content of a bin itself is NaN (in contrast to the x value being nan).

[hist] skip nan/inf bin contents when calculating Y hist range

@dpiparo

Hi @dpiparo, @hageboeck,