  Based on the Fourier extension, we propose an oversampling collocation method
for solving the elliptic partial differential equations with variable
coefficients over arbitrary irregular domains. This method only uses the
function values on the equispaced nodes, which has low computational cost and
versatility. While a variety of numerical experiments are presented to
demonstrate the effectiveness of this method, it shows that the approximation
error fast reaches a plateau with increasing the degrees of freedom, due to the
inherent ill-conditioned of frames.
