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Displaying limits in box plots (one way ANOVA)

Hi Guys,

Is there a way to display limits for a test in the box plot option in One way ANOVA?

I know of the way to add the USL and LSL to two rows in my data table and plot that column on one way ANOVA so I can see a separate box plot of my limits along with a box plot of my data but I don't want that.

I have a file which has several columnsin it and each column already has a limit associated with it (in the form of a star near the column name). I would like for these limits to show up in a box plot without having to modify the data file. I can plot histograms with the limits, but I cannot see the limits in a box plot unless I use the technique mentioned above.

Thanks.
5 REPLIES
mpb

Super User

Joined:

Jun 23, 2011

The simplest way is to assign the spec limits to reference lines for the Y axis. Just right click the axis and choose "axis settings". You'll see a place to specify reference lines and their appearance.

If you want to have the spec limits shown "automatically" then you could write a script that gets the spec limits for the column desired and feeds them to the axis reference lines. Here's an example using the Fitness data Oxy column. You need first to assign spec limits to Oxy before running the example script. The script does not check for missing spec limits. I don't claim it's the most efficient way to do this. The first part is devoted to extracting the spec limits from the column property and isolating the part needed to feed to the reference line specifications in the second part which was captured from manually inserting the ref line specs.

Thanks a lot, that worked.

I have some columns which have a :: in the name for e.g.mycolumn::11. When I use the following statement:
ms

Super User

Joined:

Jun 23, 2011

Try

How can I check if there are no limits for a column? Can I check for a null string? I am trying something like this:

mpb

Super User

Joined:

Jun 23, 2011

1. if ( ismissing(mylsl), print("lsl missing"), print(mylsl))

2. Here's an example of a much less convoluted way to get the spec limits than the one I originally posted. Again it assumes there are spec limits for Oxy which you could test for as above using if(ismissing(lsl), ...,...).