Answer: In Version 6.12, the default installation location is /Applications/Mplus. In Version 6.11, the default installation location is /Users/myaccount/Applications/mplus6.11. To determine the location of the Mplus executable, open the Terminal app and type the following command

which mplus

The which command will print the location of the mplus executable.

Answer: Open the Terminal app and type the following command

mplus -version

Note that there is a space between "mplus" and "-version" but no spaces between the hyphen and "version". "-version" is one word. The Mplus version will be printed to the screen.

Answer: Yes, Mplus can run on Mac OS X Lion, the latest version of Mac OS X.

Answer: Yes, the Mplus examples are stored in the Examples folder in the Mplus folder under Applications.

Answer: To access a second hard drive or a networked drive, go to "Macintosh HD" in the Open file dialog. Then choose "Volumes". From there, all hard drives and networked drives should be listed and can be selected.

Answer: Installation of Mplus Version 6.12 does not automatically uninstall Version 6.11. You must go to the folder for Version 6.11 and run the "uninstall_mplus" app. If Version 6.11 is not uninstalled, then this will cause a conflict with Version 6.12 when running Mplus from the command line.

Answer: When Mplus fails to read a data file that has been converted to an ASCII file from SPSS or Excel on Mac OS X, the most common cause of the problem is the end-of-line character sequence. Mac OS X uses the LF end-of-line sequence. Linux/Unix operating systems use the CR end-of-line sequence. Windows operating systems use the CRLF end-of-line sequence. Mplus can read CR or CRLF end-of-line sequence but not LF end-of-line sequence used by Mac OS X.

To determine if this is the cause of the Mplus data reading error, open the file on a Windows operating system and use Notepad to open the file. If all lines look like they have been combined into one long line, then this is an indication that the file has the LF end-of-line sequence. You can also look at this file using the more command in the Terminal window. If there are many ^M characters visible, then the file has LF end-of-line sequence. Here is an example of the more command:

more mydata.dat

The more command displays one full screen of the file at a time. Press the q key to quit more or spacebar to advance to the next page.

In the Terminal window, you can convert the file to a file with the correct line ending using perl. Type the following command at the Terminal prompt:

perl -pi -e 's/\r/\n/g' mydata.dat

Note that the file will be overwritten and no message will be printed when the process finishes. You should make a copy of the file before executing this command. Use the more command again to view the file to see if the ^M characters remain.

Answer: The mplus_setup.inp referred to in the tutorial is just a placeholder. You need to replace this file with the name of the input file you want to run. To run Mplus on the command line, type the following command

mplus filename

replacing filename with the name of your input file. For example, to run Mplus on example ex3.1.inp, you would type

mplus ex3.1.inp

Answer: The Terminal app can be found in the Utilities folder under Applications.

Answer: Use the cd command as follows

cd folder

replacing folder with the name of the folder/directory you want to change to.

Answer: The Mplus plot feature is not currently available for Mac OS X. The Mplus plot data file (GH5) may be opened in R to view some plots. Please see the Mplus and R page on our website at http://www.statmodel.com/mplus-R/ for more information.