This is mainly used within gsw, to ensure that arguments sent to the C functions are of equal length. This is a convenience, for processing data that often have this condition. For example, a CTD profile is likely to have many values for SP, t, and p, but just a single value for each of longitude and latitude. It is important to call argfix() to handle such cases, because otherwise the underlying C code will be looking past the end of the vectors storing longitude and latitude, which can yield odd results or even segmentation faults.
argfix(list)A list with all elements of same shape (length or dimension).
A list of elements, typically arguments that will be used in GSW functions.