SampleThetaPartial: Sample the vector of parameters from a multivariate normal...
In a-henderson91/vectorbornefit: MCMC fit SEIR model of vetor borne transmission

Sample a new vector of parameters (either global or local) and initial conditions using a multivariate normal dist

1 2	SampleThetaPartial(theta_in, theta_init_in, covartheta, covartheta_init, global = NULL)

`theta_in`	Vector of previous values of parameters
`theta_init_in`	Vector of previous values of initial conditions
`covartheta`	Covariance matrix for parameters. Must be same width as length of theta_in
`covartheta_init`	Covariance matrix for initial conditions. Must be same width as length of theta_init_in
`global`	Binary indicator variable if sampling global (1) or local (0) parameters. Defaults to NULL in which case no sampling happens