The point method with a h grid shift

This is identical with the equation for box 1, using the box method, Eq. 3.9 note also that the points in Fig. 3.8 are spaced the same as the box centres in Fig. 3.3. Why should one do this It will be seen in the chapter on accuracy, that some believe this to produce more accurate results. It will be argued in that chapter that the expression is, in fact, wrong, despite the good results from it. It is for those who consider the results as evidence that it is correct, that we present it here. It is, of course, possible to use the correct expression (to be developed in the later chapter) with the h grid shift - there is an argument that a point close to the electrode means a more accurate current approximation and thus better simulation results. All this is to be discussed. 

A program fragment based on this technique would be identical with that in Fig. 3.4. 

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