Message/Author 


What is available to place bounds on estimates? I have variances that keep going negative. I can think of tricks to accomplish it by forcing Mplus to square the parameter, but I was wondering if there might be an easier way. Thanks, Eric 


We usually recommend fixing small negative variances to zero and if they are not small rethinking the model. 

Anonymous posted on Monday, October 25, 2004  9:29 am



Is there any way to bound parmeter estimates between two values. I would like to restrict factor loadings to values between 4 and 4 

bmuthen posted on Monday, October 25, 2004  3:49 pm



Yes, through a trick using Model Constraint. Tihomir suggests using the two facts that the sine function is bounded by 1, +1 and that we can work with a dummy parameter (called p1 below). For instance, in a factor model, let parameter p2 be the one to be bounded: f by y1 y2(p2); !create a dummy parameter p1 (any one will do): fdum by y1@0; fdum (p1); Model Constraint: p2 = 4*sin(p1); The estimation will then take place with respect to p1 and p2 will be the bounded factor loading. 

MAH posted on Thursday, August 07, 2008  8:45 am



Similar question with respect to boundary constraints. I want to constrain an estimate to be between 01. Is there an easy way to do this in Mplus 5.1? 


You can use labeling of Model parameters and then in Model Constraint say p>0; p<1; 

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