Hi

I am trying to draw 1000 samples of data with a size of approximately 4000 )ِ (Exam data), and for each sample the difficulty factor, discrimination and guessing is calculated in order to compare all samples in these calculations, but I encountered the following problem:

Error in solve.default(object$hessian) : system is computationally singular: reciprocal condition number = 2.53258e-20

Can anyone tell me what the problem is? and what is the solution?