Encyclopaedia Index

(e) The indicial expressions

The indicial expressions referred to above are linear functions of the cell-location-coordinate indices, IX, IY and IZ; and the coefficients in the linear functions involve the total numbers of cells in these three coordinate directions, namely NX, NY and NZ.

The indicial expressions are:

These formulae express the fact that, on a slab of fixed IZ, the cells are ordered as indicated below:

IY increasing



    ^

    |    NY      2*NY    3*NY    .........   (NX-1)*NY    NX*NY

    |    NY-1    2*NY-1                                   NX*NY-1

    |    NY-2    .                                           .

    |    .       .                                           .

    |    .       .                                           .

    |    .       .                                           .

    |    4       .                                           .

    |    3       NY+3                                        .

    |    2       NY+2                                        .

    |    1       NY+1    2*NY+1  ......................   (NX-1)*NY+1

    |

    -------------------------------------------------> IX increasing

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