Matrix seems negative semi-definite

[wwbgroup]

Hi,

I'm trying to use the runMCMC function but seems that there's an error: BT runMCMC: trying to find optimal start and covariance valuesError in Matrix::nearPD(MASS::ginv(-hessian)) : Matrix seems negative semi-definite runMCMC terminated after 0.540000000037253seconds If the sample is wrong, MCMC should reject it and resample to get a new one. But it seems that there's no resample and I'm not sure what the Matrix::nearPD(MASS::ginv(-hessian)) is. Appreciate for your help.

Thanks, Weibing