setval(i, x)

setval(i, j, x)
setval(i, j, k, x )

Will set the value of the data point to x. The number of coordinates
of the point depends of dim. In dim 2 or 3, coordinates are F1 F2 or
F1 F2 F3. Can be usefully used when associated to the functions
valnd() to change data point value.

NPK Documentation, version 0.995 - 2009-10-14