R/deriv.r

In diffIRT: Diffusion IRT Models for Response and Response Time Data

  deriv=function(pars,rt,x,N,nit,model,A,W,nq,eps,delta,start,constrain){
    par=rep(999,3*nit+2)
    par[constrain!=0]=pars[constrain]
    par[constrain==0]=start[constrain==0]
    ai=par[1:nit]
    vi=par[(nit+1):(2*nit)]
    ter=par[(2*nit+1):(3*nit)]
    sd2A=par[3*nit+1]
    sd2V=par[3*nit+2]
    result=.C("DERdiff",as.double(rt),as.double(x),as.integer(N),as.integer(nit),as.integer(constrain),as.integer(max(constrain)),as.double(ai),as.double(vi),as.double(sd2A),
                      as.double(sd2V),as.double(ter),as.integer(model),as.double(A),as.double(W),as.integer(nq),
                      as.double(eps),as.double(delta),as.double(-1),as.double(matrix(0,N)),as.double(matrix(0,max(constrain))))
   out=result[[20]]
   return(out)
  }