How to get Minitab to totally disregard empty cells

[jedi105]

Hello all. I have a question regarding the entering of data in Minitab and then runn a graph. Currently, we enter our data in blocks. In other words, we like to see data for each "lot" of material in even rows. Unfortunately, each lot has varying amounts of data points. This makes the spread sheet look jumbled. To keep the data for each lot in a uniform look and feel we block each lot together. The result is there are often several cells that are left blank at the end of each lot of data. When running the graph, Minitab does not take these empty cells into acount like Statgraphics does but it does affect the chart. When Minitab encounters a blank cell it leaves a mark below the lower standard limit to show the place of the empty cell. When charting, this gets confusing. I was wondering if there was a way to get Minitab to totally disregard the empty cells when charting and calculating standard deviations and upper and lower limits. I have used stat graphics for years and found it to be limited as well. If there is any way to do this I would appreciate the info.

Thanks
Steve

 

[Miner]

If you can provide the specific Minitab chart that you are trying to create, we can better help you. Minitab can treat missing data differently depending on the graph. You could also attach your data in Excel in the same format that you enter it into Minitab, so we can duplicate this issue and develop a work around.

 

[jedi105]

We are trying to run control charts under "Stat/control charts/variable charts for subgroups/Xbar-R" as well as "Stat/control charts/variable charts for individuals". We typically enter the data like this

Lot Liner Peels Lot Exposed Peels
Lot 123456 5.55 123456 4.56
5.89 3.35
3.98 4.75
Lot 123123 2.98 123123 9.87
1.45 3.67
4.59 1.26

<edit> obviously the data is not being displayed as I want it to be in this message. I don't know how to make it look like I want it to so you can see what I am talking about <edit>

You can see the data above is nice and uniform, taking up the same amount of cells per column. But we dont always have the consistency over all of the columns so it becomes a jumble of data as we try to indicate the start of a new lot. If we were able to keep the data in the same number of rows for the entire lot, we could get away without having the lot identifier columns in between all of the data. Unfortunately, it is important for us to have the lot identifiers due to the shear amount of data points that we have to keep track of. I know it is hard to see what I am talking about visually in this message. I would be glad to post a picture of the data file so you can see what I am talking about but this forum is not allowing me to attach a picture. If anyone wants to send me a private email where I could send a picture I would be glad to do so. Private message me for my email address or send yours and I will respond with the files. Or better yet, tell me how to activate the controls at the top of this entry field on this website. I appreciate any and all help.
Steve

 

[Yew Jin]

It is important to stack the data when we want to use the tools for our study. Normally I will go to the help - help - contents section for version 15 to see on the example and the data that provided in the example on how the data needed to be stacked before I use the tools for my study.

Note: for version 14, we may get the example via help - session command help - contents

From the worksheet, we can see how the data is stacked.