Quantum Monte Carlo (QMC) simulations and the Local Density Approximation (LDA) are used to map the constant particle number (canonical) trajectories of the Bose Hubbard Hamiltonian confined in a harmonic trap onto the (µ/U, t/U ) phase diagram of the uniform system. Generically, these curves do not intercept the tips of the Mott insulator (MI) lobes of the uniform system. This observation necessitates a clarification of the appropriate comparison between critical couplings obtained in experiments on trapped systems with those obtained in QMC simulations. The density profiles and visibility are also obtained along these trajectories. Density profiles from QMC in the confined case are compared with LDA results. has offered the first such benchmark in d = 2.However, a significant obstacle exists for such a direct comparison: The confining potential produces spatial inhomogeneities and a coexistence of SF and MI phases 10 . This naturally leads to the question as to what "critical coupling" is being accessed in the experiments. Is it the coupling at which "Mott shoulders" begin to develop about a SF core? Or is it the coupling at which a Mott region pervades the entire central region of the trap? In this paper, we provide a detailed quantitative analysis of this issue. Specifically, using the Local Density Approximation (LDA) and QMC simulations, we study, for fixed particle numbers, the evolution of the density profiles of the trapped system as a function of the interaction strength and map those "canonical trajectories" onto the phase diagram of the uniform system. We also show data for the visibility 11,12 . These measurements allow us to connect the critical points obtained in QMC with those that can be seen in experiment.The QMC results presented here were obtained using two different algorithms. In the first 15 , the imaginary time β is discretized leading to a path integral for the partition function on a rigid space-imaginary time grid with local world line updates. In the second 16,17,18 , imaginary time is continuous and there are no Trotter errors associated with discretization. Bosonic world-line updates can be non-local, and, as a consequence, the Green's function can be measured at all separations. The two algorithms give consistent results for all physical quantities calculated such as the density profiles and superfluid density.The one dimensional bosonic Hubbard Hamiltonian is,Here i = 1, 2, · · · , L where L is the number of sites andis the coordinate of the ith site as measured from the center of the system. We choose the lattice constant a = 1. The hopping parameter, t, sets the energy scale; in what follows we set t = 1, i.e., all energies are measured in units of t. n i = a † i a i is the number operator, and [a i , a † j ] = δ ij are bosonic creation and destruction operators. V T is the curvature of the trap, and the repulsive contact interaction is given by U . The chemical potential, µ, controls the average number of particles.The bosonic-Hubbard Hamiltonian can also be simulated in the ca...