Since one file contains all the initial data, two names must be passed to each call, the file name and the item name. File names will have .hdf appended if it is not already there. The parameter writing and reading functions take two additional parameters, an array of parameters and the array length. Initial data need only be written for m-1 time levels, where m is the number of time levels carried for a particular grid function. All m levels can be written, but the RNPL generated program will only read the first m-1.
All routines return zero on failure and one on success.