How to save a mass of histrogram in one root file?

[zs155167]

I have 6 directories in one root file. Each directory saves some TH1F like pictures, but for 6 directories there are too many. If there are large events, it can not be reserved. How to solve this problem?

[couet]

@zs155167

but for 6 directories there are too many. If there are large events, it can not be reserved.

What do you mean exactly ? ROOT refuses to save some histogram in a TFile ? if that’s the case you should get some error message. Can you post it here ?

[zs155167]

For example, one directory has 3000 TH1F.And I have 6 directories, there are 24000 TH1F in one root file. Can it be saved for this number of historgrams?

[couet]

@pcanal will know if there is a limitation