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) ;
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: LAM2-LAM4 *** ERROR Label is not a valid parameter label. This label will not be available for use in MODEL CONSTRAINT: LAM2-LAM4 *** ERROR Variable names may only contain letters, digits, and the underscore '_' character: LAM2-LAM4 __________________ __________________ 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 email@example.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?
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 hand-calculations 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?
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 y-axis (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?
Rich Jones posted on Tuesday, June 05, 2012 - 2:27 am
We have developed some Stata code to transpose Mplus.out into graphviz code. It works pretty well, not pefectly. Right now better for on-the-fly 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.
I have run a a 2-group 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 group--for the same item). Is that possible to do in Mplus?
One alternative could be to export the Mplus-generated ICCs with a transparent rather than white opaque background, and overlay the JPGs in an external program (Word or Paintbrush, etc.).
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.