Hi @TimboK1 ,
Thanks for watching the webinar. I will do my best to answer your questions.
- In my example for the cattle data, it did not have any missing data they were 0s. I misspoke by calling them missing as in true blank values. If they were true missing data then using Missing Data Pattern underneath the Table menu or Analyze>Screening> Explore Missing Values would be a better start. There are a lot of options for imputing and even clustering for missingness. In your case, you would have to use the Missing value imputation option or recode the missing values to 0 if they really 0 or not measured/present. This will cause some interesting differences and confidence in those differences. Sometimes the original data is a 0 and then normalization methods that have a log transform step will cause these values to be missing. In these cases an offset is usually used (by adding a 1 before transforming) so the final transformed value is still 0 as opposed to a real missing value (issue with measuring the sample).
- Yes, I agree that one has to segment the groups in these cases. I prefer to do the search by group given that the amount of missing or 0's can be disproportionate to a particular group. A by group option would be good to add, but would require a little extra coding. I can take a look at what it would take to do this in JSL, but it will take me a little time as to the best approach (and to put a little user interface option for a By Group column).
- For JMP Pro 17 or JMP Pro 18 (released in March), this is currently not possible. I do something similar as you did. I save out the Means difference table (Red Triangle within Response Screening and choose Save Tables>Save Means Differences) and then use graph builder with a local data filter. I also will use Rows>Row Selection>Select Where to select rows that are below a threshold of choice and difference threshold. Then I use Rows>Row Selection>Name Selection to Column to create an indicator column(s) that I can use to concatenate for a column I can use in the color option in graph builder. Another option is to use a column formula where the conditions are added and an if statement. I like this option better since it is a single action and saved within the column as to what I am doing.
Hope that helps.
Chris Kirchberg, M.S.2
Data Scientist, Life Sciences - Global Technical Enablement
JMP Statistical Discovery, LLC. - Denver, CO
Tel: +1-919-531-9927 ▪ Mobile: +1-303-378-7419 ▪ E-mail: chris.kirchberg@jmp.com
www.jmp.com