Using TTree entries for both bin X values and Y entries of a histogram

I have a TTree and would like to make a 1D histogram where the numbers in one column (integers) will be used for the X values for the bins in a 1D histogram and the entries in another column will be used for the entry value in the corresponding histogram bin. Can someone recommend an easy way to do this?

may be:



That format creates a 2D histogram with each entry in the tree doing an hfill at the X and Y location. What I’m looking for is a 1D location with the X bin value given by one tree column and the contents of that bin given by the other column.

I don’t think you can do this with a simple Draw command. You would need to create a histogram, set the branches, loop through all entries, and use either a weighted Fill or SetBinContent for each entry.

Have you tried:


that will connect te (x,y) points with a line.

This looks to be the only solution. I was hoping for something simpler but I did exactly what you suggested and that solved my problem.

I am sure what you mean but what about;



[remove unintentional extra text in 3rd parameter]

Sorry for the confusion about which comment I was replying to. I got what I wanted by looping over entries. I could not get the “L” option in tree->Draw to give me a 1D histogram.

the “L” was not intentional :slight_smile:

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