Facilities for input of numeric data. Programs that take numeric data as input can use the 'numin' facilities for reading this input from data files. The specification string also gives the file name and a range of lines to read. If the filename part is present, the defaults are the entire file and indexes starting at one.
Line numbers start at one.
The index specifications give the positions of items to read within a line, with the first item in a line having index one. An index of zero is also allowed, and gives the value zero without any reference to the file. Any excess items in the line are ignored, but the line must contain the items that are required. The indexes of these items need not be in increasing order. It is an error for the specification to give more item indexes than the number of items required.