What does "opr" represent in dp_reduce(array, "opr")?

[largedimples]

Please do not give me the answer but if you can direct me to site that will tell me what OPR represent in the statement dp_reduce(array, "opr"). I think opr represent operation but I need to find out what it does in this statement. Please don't give me the answer-just direct me to the right site to learn more about this.

thanks in advance

 

[jtbell]

I think you need to give more information about the program that you are working on. dp_reduce() doesn't appear to be a standard Fortran function. I did a Google search for '"dp_reduce" fortran' and got exactly two hits, one of which is this thread!