Message/Author 

Daniel posted on Tuesday, May 11, 2004  10:20 am



A reviewer asked us to graph development in a LGM by class from our Latent Growth Class Analysis with an ordered categorical dependent variable. My question is, what is the best way to graph class differences in development in a single chart? Further, is it possible to add some kind of confidence intervals to a graph with your plot utility? 


If you ask for PLOT3 in the PLOT command and use the SERIES option, you will get a choice of estimated probablities. All classes are plotted in the same plot. There is no option for adding confidence intervals. 

Anonymous posted on Tuesday, April 19, 2005  3:41 pm



Could you give me the correct syntax for PLOT when there is an s (slope) and q (quad) factor in a latent growth mixture model. Is it? PLOT: TYPE IS PLOT2 PLOT3; SERIES IS wjl54  wjl5 (*) ; OR PLOT: TYPE IS PLOT2 PLOT3; SERIES IS wjl54  wjl5 (s) wjl54  wjl5 (q) ; Thanks in advance!! 


The correct syntax is: PLOT: TYPE IS PLOT3; SERIES IS wjl54  wjl5 (s) ; 

Salma Ayis posted on Friday, June 09, 2006  2:42 am



Please advice on how to obtain Item Characteristic Curves(ICC) plots for a set of of (binary)variables. I would like to have a plot for each variable as well as one for all in the same graph. Is that possible in Mplus?. I very much appreciate your anticipated assistance!. 


You can obtain Item Characteristic Curves and Influence Curves when you use maximum likelihood estimation by asking for PLOT2 in the PLOT command. You will then see them listed in the graphics menu. 

Salma Ayis posted on Saturday, June 10, 2006  11:12 am



Thanks very much!. I am afraid I need further assistance & hope you don't mind!. I am rather new to the IRT and this is the first time I intend to use it. Example 7.29 of the user's Guide seems fairly close to what I want: I have 10 binary variables, they are likely to form a construct and to classify subjects into clustes(latent classes). If my understanding is correct then example 7.29 will suit what I am trying to fit. I tried to run this example first to look at Item Characteristic Curves and start from there but I had few error messages such as: *** WARNING in Variable command Variable DZ, used in KNOWNCLASS specification, has been removed from the USEVARIABLES list. Subsequent errors may occur if this variable is used elsewhere. *** ERROR Variable names may only contain letters, digits, and the underscore '_' character: LAM2LAM4 *** ERROR Label is not a valid parameter label. This label will not be available for use in MODEL CONSTRAINT: LAM2LAM4 *** ERROR Variable names may only contain letters, digits, and the underscore '_' character: LAM2LAM4 __________________ __________________ I thought some files may have been corrupted after they were transfered or ..any thing like that. Have deleted the files and copied them from the Mplus home_page again, but had the same error!. Now I need your advice in: 1 am I right that example 7.29 have similar aims to my needs? 2 any help with the error messages please!. I very much appreciate your time! 


Example 5.5 is an IRT example. I think this is what you should be looking at. The example you are looking at uses IRT but it is a specific twin model. From the error messages it sounds like you are not using Version 4 which introduced a list function for labels. If this is not the case, you need to send your input, data, output, and license number to support@statmodel.com. 

Myung Kim posted on Friday, April 09, 2010  11:31 pm



I'm working with a multilevel categorical model with a binary outcome. I'd like to plot the predicted probabilities (logistic curve) for a predictor in the model. When I use the command line, "Plot: TYPE=PLOT2;" no graph file is produced. When I use "Plot: TYPE=PLOT3;" a graph file is produced, but it is limited to scatterplots and histograms. Is there a way to produce a plot of the logistic curve for this model? Thanks. Myung 


If you are using the SERIES option, then the plot is not available. 

Jon Elhai posted on Tuesday, July 06, 2010  5:12 pm



Linda, I had previously in version 5 used the following syntax to produce a plot of my factors in a factor mixture model: PLOT: Type is plot3; Series is F1 (1) F2 (2) F3 (3) F4 (4); Where F1, F2, F3, and F4 are my factors  labeled just as they are in my model statement. In version 6, when I try this, I see an error message that says: "*** ERROR in PLOT command Unknown variable in SERIES option: F1 So I'm wondering if the syntax for plot3 has changed in Version 6? 


Please send the full output and your license number to support@statmodel.com. 

Tammy Kochel posted on Wednesday, November 10, 2010  11:40 am



I have run a SEM with a binary observed DV and WLSMV estimator. When I use Plot2 and view the probabilities for the DV relative to changes in the value of a specific IV "a", what value does it hold all of the other IVs "b" "c" etc to? My interpretation of the example in the Mplus manual led me to think they were held to a value of 1, but my handcalculations against those produced by Mplus lead me to think otherwise. Will you please clarify the value Mplus assigns to the covariates for probability calculations in plot2? Thank you. 


The mean of the covariate is used as the default. 

Tammy Kochel posted on Wednesday, November 10, 2010  12:23 pm



Thanks. When the covariates are binary, is the modal category used or the actual mean? 


The actual mean is used as the default. 

Cecily Na posted on Wednesday, December 08, 2010  2:01 pm



Dear Linda, Is there a function to get a model graph with path values and error variances? There is such a function in LISREL. Could you tell me the command syntax? Thanks! 


No, Mplus does not create path diagrams. 


I have 2 questions regarding the IRT Plots in PLOT 2 that I was hoping you could help me with. 1. Is it possible to change the scale on the yaxis (Probability) for an item characteristic curve so that it is in increments of 0.10 rather than 0.20? 2. When you chose the item characteristic curve plot, the fourth screen (for the set up) has the option to change the number of steps. I can't find this in the user manual, but is this just specifying what points on the line are being plotted? So choosing 1/100ths of a standard deviation would provide a much smoother plot? Thanks 


My mistake, I just found the answer to the 1st question. Just need to know about the second. Thanks, 


2. Yes. 


Hello I know Mplus doesnt produce path diagrams. But can you tell me how did you draw ones in the User's Guide? Which software is it? 


We use Freehand. 

Rich Jones posted on Tuesday, June 05, 2012  2:21 am



Hi Burak, FWIW I've been using Smartdraw for many years. A long time ago it was an inexpensive alternative to Visio. Nowadays it is an expensive alternative to Visio. Any other Smartdraw users out there want to join me in a project to develop a path diagramming library for Smartdraw, drop me a line. Rich jones@hsl.harvard.edu 

Rich Jones posted on Tuesday, June 05, 2012  2:27 am



Also, We have developed some Stata code to transpose Mplus.out into graphviz code. It works pretty well, not pefectly. Right now better for onthefly path diagrams rather than final publication quality path diagrams. Someone who knew what they were doing could probably take that Stata code and make it C, Java or Python pretty easily. Drop a line if you're interested. Rich jones@hsl.harvard.edu 


Hello, I have run a a 2group IRT model, and would like to generate ICCs for the two ethnic groups in the same plot (overlaying the ICC for one group with that for the other groupfor the same item). Is that possible to do in Mplus? One alternative could be to export the Mplusgenerated ICCs with a transparent rather than white opaque background, and overlay the JPGs in an external program (Word or Paintbrush, etc.). Is either of these possible? Thank you. 


Neither option is available. You can save the data by using the Save Plot Data option under the Plot menu for each of the groups and then combine the data and plot this using another program like R or Excel. 


Hi Linda, thank you. I am trying to do this, but the Save Plot Data option is currently grey rather than black, indicating that I cannot select this option. Why would the Save Plot data option be grey for my OUT file, when I have requested PLOT3? 


OK, I am seeing now that this is an option once I have generated the ICC graph. Then I can select Save Plot Data. Thank you. 

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