Dear all
I am using the polychroric command to calculate the correlation matrix of a set of 17 variables ( 8 binary 0-/1 and 9 metric).
After lenghty calculations STATA shows a matrix with missing values in the matrix, mostly between metric and binary variables. 4 metric variables have missing values correlations with binary variables.
The results window show these messages. In red:
could not calculate numerical derivatives
missing values encountered
initial values not feasible
too few quotes
no variables defined
And in green:
numerical derivatives are approximate
nearby values are missing
Do you have an idea why am I facing these results?
How can I assure that the corr. matrix is positive defined?
Do you know if using R poly command would dela with the missing values? .
Thank you
Juan Julio
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