Computes the part of the loglikelihood function relevant to optimizing theta for step 1
ISOpureS1.model_optimize.theta.theta_loglikelihood(ww, tumordata, dd, model)
the theta weights corresponding to patient dd, a 1xK matrix
a GxD matrix representing gene expression profiles of tumor samples
the patient number
list containing all the parameters to be optimized
The negative of the loglikelihood relevant to theta