Working with data tables is, of course, an important part of working with JMP. The data table enables JMP to access your data through various analysis and graphing platforms. You can enter your data directly into a JMP data table, and you can save that data table for future access. Or, you might have data saved in a different file format, or in a relational database. In those cases, you have to either import the data or query it in order to use it in JMP. For now, let's focus on data that are already saved in a JMP data table. In order for you to use the data in JMP, you first need to open the data table. A single JSL function is responsible for opening your saved data table: the Open function. This function takes an argument that specifies the file as a character string. That is, the argument specifies the path to the data table. For a relative path, you simply specify the file name and extension. That means that the path is relative to the current default directory or file path. You can also specify the path explicitly using the full path with the filename and extension, which makes the path absolute. And using an absolute path is the safest way for you to be sure that the correct file will be opened. Now, you might be thinking, "how can I know what that path will be for a future data table, or for another user running my script?" Well, you'll see that there are JSL functions that enable your script to retrieve that information when the script runs. Finally, if you use the Open function without specifying an argument, then JMP presents the standard "file Open" dialog box to the user when the script runs. And in all cases, the Open function opens a data table and returns an object reference to it, which can then be stored in a variable.
