An algorithm for contouring and interpolation of data using bilinear finite elements

An algorithm based on the finite element method is developed for contour plotting and interpolation of field data. The method suggested in this paper is suitable for both regularly and irregularly distributed data points and especially for output from numerical models. The technique adopted here uses the bilinear finite element to determine the piecewise smooth surface connecting four data points. The gradients of the piecewise surfaces are then modified at the corners of the quadrilateral elements to produce a globally smooth surface. After this step, a 12-degree-of-freedom system is adopted in each element to generate contours. This paper gives details of the mathematics behind the algorithm, its strength and limitations and results of application.