Plotting Error Bars

K

Kerrowman

New Member
#1
#1
I have calculated a series of values for the efficiency of an electrical system together with the uncertainty for each value as shown in the table below. I would like to plot these values as a graph in Mac Numbers (or Excel, as the principles will be the same) along with error bars for each point.

Ideally, I would like to set the uncertainty value as the error bar for each point but the spreadsheet limits me to one error bar value for all the points. So do I list all the values, get the Mean and then calculate the 'Standard Error of the Mean' and then use that as my error bar value or something else?

Thanks

Data Table.png
 
H

hazelsarti

New Member
#2
#2
Hi,
If using Excel you can set seperate error bars for each point.
Made a graph by highlighting the data in the first two columns. Once you have the graph, click the '+' to the right of the graph and tick the box next to 'error bars'. Then, click the arrow directly to the right, or double click the error bars themselves, and a formatting bar wil appear on the right-hand side. Go to error bar options (the symbol that looks like three bars on a bar chart) and then select 'custom' under 'error amount'. To the right of that is a box labelled 'specifiy value'. Click this and it shoudl bring up a window titled 'Custom error bars'. Delete the values within the positive and negative value boxes and for each value box highlight the column in your excel sheet containing each of the error values (you dont want to highlight the column heading). then click okay and it should apply the respective error bars to each of the points.
Hope this was what you were asking for and if you need further help you can always google it, there's loads of youtube videos evidencing how to do it.
 
You must log in or register to reply here.