Case Sensitivity

Whenever the NETFLOW procedure has to compare character strings, whether they are node names, arc names, nonarc names, or constraint names, if the two strings have different lengths, or on a character by character basis the character is different or has different cases, PROC NETFLOW judges the character strings to be different.

Not only is this rule enforced when one or both character strings are obtained as values of SAS variables in PROC NETFLOW’s input data sets, it also should be obeyed if one or both character strings were originally SAS variable names, or were obtained as the values of options or statements parsed to PROC NETFLOW. For example, if the network has only one node that has supply capability, or if you are solving a MAXFLOW or SHORTPATH problem, you can indicate that node using the SOURCE= option.

If you specify

  proc netflow source=NotableNode

then PROC NETFLOW looks for a value of the TAILNODE list variable that is NotableNode.

Version 6 of the SAS System converts text that makes up statements into uppercase. The name of the node searched for would be NOTABLENODE, even if this was your SAS code:

  proc netflow source=NotableNode

If you want PROC NETFLOW to behave as it did in Version 6, specify

  options validvarname=v6;

If the SPARSECONDATA option is not specified, and you are running SAS software Version 6 or have specified options validvarname=v6; using a later version, all NAME list variable values in the ARCDATA= data set are uppercased. This is because the SAS System has uppercased all SAS variable names, particularly those in the VAR list of the CONDATA= data set.

Entities that contain blanks must be enclosed in single or double quotes.

See the section Cautions for additional discussion of case sensitivity.