There are two well-known data types for JMP columns, Numeric and Character. There's an oft-ignored third data type that's been in JMP since the beginning, Row State. This data type stores color, marker and other row state information for each row.
So, if you spend time coloring, marking, selecting, excluding rows and want to make sure it's saved, create a Row State column to hold on to it. Then you can color, mark, exclude, etc., all you want, and you can always get back to the stored states.
2. Date/Time/Datetime columns should be Numeric
Computers generally store dates as a number of time units from an epoch. JMP stores date and datetime values as the number of seconds since 12:00 AM UTC, January 1, 1904. This is important to consider when you do math using the columns. For example, if you subtract one date value from another, the result will be the number of seconds between them.
Admittedly, the number of seconds between two dates can't be interpreted intuitively, so you'll need to divide the result by the number of seconds in the time units that you're more interested in. As an example, you divide by 86,400 seconds – the number of seconds in 24 hours – to get the number of days. JMP has a number of functions to give you these: In Minutes(), In Hours(), In Days(), In Weeks() and In Years() functions. The numeric argument specifies the number the time units from the function name.
The Date Increment() and Date Difference() functions will do this extra bit of math for you automatically if you want these simple calculations.
If you've ended up with date or time values stored as character strings, these videos will show you how to convert them to numeric values.
3. Value Ordering property
JMP normally orders categorical values alphabetically. So, Before, During and After will come out as After, Before, During. If you want your values in a different order, you can use the Value Ordering column property.
With this property, you can specify the order you want values to appear on axes and in reports.
Right-click at the top of a column and choose Column Properties -> Value Ordering. Then, arrange the values in the order you'd like them to appear.
4. Copy/Paste into most dialogs
Sometimes filling in fields in a dialog in JMP can be a pain. For example, the Value Labels property requires two field entries and a click for every value/label pair.
Consider a table of stock ticker symbols that you'd like to label with company names.
For each ticker symbol, you need to put the Value and Label and then click Add.
It's easier to get the list of symbols and company names in a data table, and the copy and paste the values.
Just make sure you've got a tab-separated list on your clipboard.
Similarly, you can paste column names into JMP's launch dialog.
5. Standardize Attributes
As data tables get larger with more and more columns, you'll appreciate a way to change the data types, modeling types and properties for lots of columns all at once. That what Cols -> Standardize Attributes… does.
Just select all the columns that need to be changed and then launch Standardize Attributes….
This makes it easy to change data that may have been imported as Character columns to Numeric. Easy peasy!
Bonus: Don't miss the Recode option at the top of the dialog. Clean up a bunch of columns all at once!
6. Drag Columns into report windows
Did you know that the columns pane on the left side of the data table can serve as a handy way to add columns to an existing analysis report window?
Just grab the column name from the panel and drag it into a report window.
You may find it easier to set up an axis the way you want it using an existing graph and the save the axis settings to a column property by right-clicking on the axis.
8. Name Selection in Column
As you explore your data, you may find a group of rows that stand out to you. Maybe they are outliers. Maybe you found them through the Data Filter. Regardless, once you've selected a group of rows, you can create a new column to assign them a name or category using Rows -> Row Selection -> Name Selection in Column….
You can do this multiple times to name multiple groups. Just keep saving the names to the same column and leave the Unselected field blank until you've gotten the last group.
As data volumes grow, plots get busier and busier. It can become difficult to interpret a cloud of points. If this happens, try using Transparency to show the most dense part of your plot.
Just right-click on the graph and choose Transparency…. Try a setting around .25 or lower.
As I said that the start of my first 10 Things You Don't Know About JMP post, I didn't expect that you wouldn't know all of these. So I thought I'd leave a space for you to add your own and share something you think others don't know.
Post your favorite thing that you think people don't know about JMP in comments. I'll bet you can even teach me something.