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Hello All,

I have been trying to conduct multiple imputation with a two level (occasion nested within individual) model that contains several continuous and categorical variables. However, when I click 'Start MCMC Run', I get the following error message:

??? Index exceeds matrix dimensions.
Error in ==> sampleymiss at 77
Error in ==> mcmcdriver at 889
Error in ==> gui_2levmixresp>pushbutton16_RunMCMC_Callback at 264
Error in ==> gui_mainfcn at 96
Error in ==> gui_2levmixresp at 46
Error in ==>
@(hObject,eventdata)gui_2levmixresp('pushbutton16_RunMCMC_Callback',hObject,even
tdata,guidata(hObject))
??? Error while evaluating uicontrol Callback

I've re-downloaded and installed the latest versions of both MLWIN and Realcom-Impute, tried moving all of my auxiliary variables except the constant to the response variables column and tried calling my categorical variables 'ordered' and 'unordered' and still get the same message. I also used a separate dataset I'm working with (that includes the same 2 levels (occasions nested within individuals) and got the same error message.

If anyone can provide any suggestions as to what I might be doing wrong and how it might be handled, I would really appreciate it.

Many thanks,

Ryan

Hi all,

I've got the same problem and a bit of idea where the problem is [though not the solution].
Just before the lines posted above, in my case the command line window has:
no level 1, level 2 units = 15253, 2323.
???? Index exceeds matrix dimensions.

Questions: What is the size of acceptable index matrix? Does this overreach have to do with the number of level 2 and level 1 units [my presumption is it does]? Is it possible to re-allocate memory to this matrix to cope with certain combinations of level 2 and level 1 units? For instance, if I want to allocate most allocatable memory to Realcom Impute [given that some Windows OS have problems addressing all 16GB RAMs, not that I've got them], how to do so?
Is there a rough guide to increase memory for this apparently crucial matrix?

Thanks a lot to Bristol folks for the fantastic works all these years,
gindotampu

Could you check whether you still get the same problem with the most recent update of Realcom-Impute? There have been some recent bug fixes in the routine that this error message is referring to.

As far as the maximum memory it can use goes, Realcom-Impute is currently compiled as a 32 bit windows executable. This should mean that on a 32 bit system it can use up to 2Gb and on a 64 bit system up to 4Gb. This of course assumes that Windows is able to provide it with this much using a combination of RAM/Swapfile.

Dear Chris,

So far so good. I don't expect any more trouble with the June release.
Again, many thanks.
gindotampu