Hartwig, R. R.J. L. Encarnacao2015-09-292015-09-2919811017-4656https://doi.org/10.2312/eg.19811019This is a method to be applied in R&D. 1. A surface is generated, containing exactly all given points z(x,y). 2. The degree of accuracy is gradually specified. One can swap 'ACCURACY for SPEED'. 3. 'Out of the picture' iso-lines, z-values, gradients, curves, curved cuts, etc. are specified interactively, and drawn, and 'converted into numerical data'. 4. Such data can be used for calculations, or for further presentations, etc... VISUAL VALUATION' and NUMERICAL CALCULATION are compound in a tool for 'cyclic' interactive analysis.10.2312/eg.19811019