CMM software support FAQs
If you already own a copy of MLwiN and have not upgraded to the latest version, please upgrade to MLwiN for free as this may solve some problems.
Other sources of help
- Try our MLwiN user forum where we welcome all users to post enquiries
- You can also join the Multilevel Modelling discussion list
- If you have bought MLwiN, you may be entitled to email support. (You are entitled to free email technical support if you have bought MLwiN or MLn (exceptthe PhD version)
- Note: If you are a UK academic and have downloaded the free version you are not entitled to free support.
- Resources for using MLwiN
- Our online course with its practical instructions for using MLwiN and other software
FAQs
- Downloading MLwiN
- MLwiN 2.1/beta/trial/other versions
- Realcom
- MLwiN and operating systems
- Getting data in and out of MLwiN
- Large datasets
- Worksheets
- Sample size, significance testing and suitability of data
- Errors and crashes: Error messages during estimation/ implausible results
- Errors and crashes: crashes/problems opening MLwiN or worksheets
- Errors and crashes: Other errors/problems
- How do I…? Categorical variables
- How do I…? Commands and macros
- How do I…? Discrete response models
- How do I…? Longitudinal data
- How do I…? MCMC
- How do I…? Missing data
- How do I…? Parameters and parameter estimates
- How do I…? Partitioning variance and the intra-cluster correlation
- How do I…? Residuals
- How do I…? Standard errors
- How do I…? Using weights
- Miscellaneous
Downloading MLwiN
- For all questions about downloading and purchasing MLwiN please go to Ordering MLwiN FAQS
MLwiN 2.1/beta/trial/other versions
- Should I uninstall the MLwiN 2.10 beta version I have before installing a later version?
- I already have MLwiN 2.10 beta but the upgrade to the latest version will not work
- What is the difference between the training, the trial version and the full version?
- Can I open SPSS/Stata/Minitab worksheets using the training version of MLwiN?
Realcom
- Does multiple imputation in Realcom work with the free trial version of MLwiN?
- Other problems with Realcom or Realcom-Impute
MLwiN and operating systems
- What are the MLwiN system requirements?
- Can I install MLwiN onto a Mac or Linux system?
- Is MLwiN compatible with versions of Windows later than 7?
- Does MLwiN make use of Multi-core/Multi-processor environments?
- Is it possible to run MLwiN on a Citrix-desktop?
Getting data in and out of MLwiN
- How do I get data into MLwiN?
- How do I get data out of MLwiN?
- Are there any issues I should be aware of when opening my Stata/SPSS/Minitab files with MLwiN 2.1?
- Opening a .dta (Stata) worksheet, I get the error message 'Duplicate name(RSTA)'
- I'm trying to export a number of variables from MLwiN, but only the first 5 appear in the text file
Large datasets
- How do I know MLwiN can handle the model based on my own data?
- I'm having problems importing a large dataset from SAS
- I'm having problems working with a large dataset in MLwiN. Does MLwiN have a limit to the size of dataset that it can handle?
Worksheets
- How do I increase the worksheet size?
- Does each row correspond to a single record right across the MLwiN worksheet?
- Does it matter what order the data appears in in the worksheet?
- Other questions about worksheets
Sample size, significance testing and suitability of data
- Sample sizes for Multilevel Models
- MLPowSim
- Sample size, significance testing and suitability of data
- How can I calculate confidence intervals in MLwiN?
- What significance tests for both random and fixed parameters are available in MLwiN?
- How do I test whether two coefficients are equal?
- How do I test whether more than 2 coefficients are equal?
- How do I test if an interaction between a continuous and a categorical variable is significant?
Errors and crashes: Error messages during estimation/ implausible results
Go to Errors and crashes >>
- I get an error message when I run my model/ numerical problems
- I got an error message 'cannot allocate rmatrix(ws)(like)'
- I tried to run a binomial model and got an error message
- I tried to run a binomial model and got an error message (2)
- When do I allow negative variances?
- I get an error message 'wrong parameter…' when using MCMC
- When I get the error message "MCMC error 0315: prior variance matrix is not positive definitive" while running a multinomial model using MCMC, what exactly do I need to do to the numbers in C1096?
- I get an error message asking me to 'generate unique ID codes'. How do I do this?
- Implausible results or convergence problems
- MLwiN is giving the standard errors of parameter estimates as 0, but I know from comparison with other software packages that the standard errors should not be 0
Errors and crashes: crashes/problems opening MLwiN or worksheets
- Why has MLwiN crashed?
- The European convention of using a comma as a decimal point causes MLwiN 2.10 Beta to crash when using the Intervals and Tests window
- MLwiN fails to open after changing the default worksheet settings
- When I run MLwiN I get the error message "Pre or Post file does not exist (post)"
- I have a worksheet saved on a network drive that I can't open using MLwiN
- When I try to open the worksheets for the LEMMA course I get an error message
- When I double click on one of the worksheets for the LEMMA course, it opens with notepad not MLwiN
Errors and crashes: Other errors/problems
- When trying to plot a graph, I get the error message 'Failed to open Graphics Server'
- Why has my data become corrupted?
- I can't get the LOGOn command to work
- I noticed a difference in values I get between versions of MLwiN
- Other errors/problems
How do I…? Categorical variables
- How do I update the category labels for a categorical variable?
- I've recoded a categorical variable, but the list of category codes I see when I press Categories has not been updated
- How do I get rid of an unneeded dummy variable/ response category?
- Other questions about categorical variables
How do I…? Commands and macros
- How can I easily save and run commands?
- When I work with MLwiN using the various windows, is there any way to record the commands that will do the same thing?
- I copied commands generated by MLwiN when I was using the GUI and pasted them into a macro, but when I ran the macro I got an error message
- Output from my macro is not appearing in the Output window
- Can I run my old macros written in MLn under MLwiN?
- Will macros written for version 2.02 work with earlier versions of MLwiN?
- I’d like to call MLwiN from the command line. Is that possible?
- Other questions about commands and macros
How do I…? Discrete response models
- How can I specify a binomial response model using a macro?
- What is the command for specifying the denominator when fitting a binomial or multinomial model?
- Why is the log-likelihood value not displayed in the Equation Window when a Binomial or Poisson model has been fitted?
- MLwiN gives different results to SAS and Stata
- How do I calculate variance functions for multinomial models?
- How do I interpret the estimates for the fixed part parameters in a Poisson model?
- Other questions about discrete response models
How do I…? Longitudinal data
- Does MLwiN need repeated measures data to be in long or in wide format?
- Is it possible to define an AR process for the random effects at level 1?
- When should I allow level 1 errors to be autocorrelated?
- Where are the time series macros?
How do I…? MCMC
- Can I change the length of the burn-in without re-running the model?
- Running MCMC from a macro doesn't appear to work
How do I…? Missing data
- How do I explore the patterns of missingness in my data? (PDF, 381kB).
This document shows how you can produce a list of all the patterns of missingness in your data together with information on how frequently each one occurs.
How do I…? Parameters and parameter estimates
- Where is the model fitting information stored in MLwiN?
- Is it possible to output the error variance-covariance matrices for parameters?
- Is it possible to constrain parameters in MLwiN?
- How can I constrain random parameters to zero?
- How can I constrain fixed parameters to zero?
- How can I constrain parameters to values other than zero?
- How can I constrain two parameters to be equal?
- Other questions about parameters
How do I…? Partitioning variance and the intra-cluster correlation
- Partitioning variation across levels - more information
- Where can I find the random parameter matrix in MLwiN? How do I use this to work out the residual ('unexplained') variance at each level?
- How do I calculate the amount of variation at each level for nonlinear models?
- What is the intra cluster correlation?
How do I…? Residuals
- My residuals column is too short
- Should the comparative SD output when I calculate the residuals be different for each row?
- Residuals slide presentation with voice-over plus transcript
How do I…? Standard errors
- Sandwich estimators for standard errors - more information
- Can MLwiN produce robust standard errors?
- Other questions about standard errors
How do I…? Using weights
- What are weights and how do I use them?
- Is the weights facility in MLwiN still experimental?
- Differential weightings - more information
- How do I use weights in a multiple membership model?
Miscellaneous
- My Names window looks different to the screenshots in the training materials and I can't find all the buttons mentioned in the instructions
- Is it possible to fit splines in MLwiN?
- Does each row correspond to a single record right across the MLwiN worksheet?
- My level 2 variables are being treated as level 1 variables
- MLwiN can no longer PRINT windows