Autorange on a histogram does not work

ROOT
1

Hello All,

I have a plain-text histogram file with x-values and their frequency. I am trying to load that into a root histogram as follows:

[code]float location,b;
int frequency=0,loop=0;

TH1F *h = new TH1F("h","h",1000,1,1);

while (!feof(datafile)){
	fscanf(datafile,"%f %i",&location,&frequency);
	for (loop=0;loop<frequency;loop++) h->Fill(location);
}[/code]

From the root manual, I have set the lower axis value lessthan or equal to the higher axis value for auto-range. However, the histogram does not have the correct ranges. What am I doing wrong?

Root code, the histogram plain text data and a matlab generated histogram (showing the correct range) are attached.

Thanks,
Karthik.
files.zip (14.3 KB)

2

Hi,

You must ‘h->BufferEmpty();’ after being done filling, do flush the filling and calculated the boundaries.

Cheers,
Philippe.

3

Hello

Can you please explain what you mean by “do flush the filling and calculated the boundaries”. ?

I cannot see a flush method.

Thanks.

[quote=“pcanal”]Hi,

You must ‘h->BufferEmpty();’ after being done filling, do flush the filling and calculated the boundaries.

Cheers,
Philippe.[/quote]

4

Hi,

You must call the routine:h->BufferEmpty();to do the flushing I am talking about … See root.cern.ch/root/html/TH1.html#TH1:BufferEmpty.

Cheers,
Philippe.