These are controller timing functions and scale the vector to a proper range and fit it to the zones of the current section. The vector length must be calculated with sheetlen function, which performs the calculation based on the sum of all zone lengths divided by the length value of the controller-only instrument.
do-fit scales the values around a center 64, which is used in some synthesizers to represent the default value of the current sound, to which changes are to be made adding or subracting values from it.
do-fit2 scales the values absolutely to a given min and max values.