Bin-centered X values on Histograms
I am trying to make a histogram of some data I have:
| 12.5 |
| 16.4 |
| 16.6 |
| 18.0 |
| 18.6 |
| 22.3 |
| 23.4 |
| 23.7 |
| 28.1 |
I have chosen 5 bins with width 4 and bin start 10. When I plot this histogram, everything seems fine. I have attached an image of this (Graph 21).
However, I apply the bin-centred X values for the purpose of fitting a graph through the centre of the bin and, the bars on the histogram appear to show incorrect data. I have attached an image of the wrong data (Graph 16). I believe the issue is because the bars now begin at the bin centre, because if I represent the data with a marker and line instead of bars, the data appears correct.
Is there any way I can fix this such that the graph is fitted through the centre of the bins but keeping the histogram displayed correct with bar mode?
Forum
Support
Gallery
Igor Pro 9
Learn More
Igor XOP Toolkit
Learn More
Igor NIDAQ Tools MX
Learn More
I dealt with this in one place and I eventually created different x-wave for each set of data - but in this case I have xwave and ywave pairs. If you are using x-scaling, you can shift the bar graph using Offset option in GUI, so it is centered by shifting it by half of the bin width. This applies command ModifyGraph offset={-2,0} in your case. If you do this only for the bar graph, it will look as expected and is easy to do through GUI.
March 30, 2020 at 08:22 am - Permalink
You have analyzed the source of the problem correctly. It is a difficult problem that has no terrific solution. The various things you can do are discussed in our help: DisplayHelpTopic "Curve Fitting to a Histogram".
March 30, 2020 at 12:00 pm - Permalink