*To*: mathgroup@smc.vnet.net*Subject*: [mg10480] ReplacePart?*From*: "Scott Morrison" <scott@morrison.fl.net.au>*Date*: Fri, 16 Jan 1998 04:35:03 -0500*Organization*: The University of Sydney, NSW, Australia

I have a list of pairs of the form: gt={{3,5},{{},6},{7,{}},{{},{}},{{},56},{{},3}}; The empty lists inside pairs are being used as placeholders. I want to replace these with the elements of b: b={a1,a2,a3,a4,a5,a6}; hopefully resulting in the list {{3,5},{a1,6},{7,a2},{a3,a4},{a5,56},{a6,3}} I had thought that ReplacePart could do this, as it says: "ReplacePart[expr, new, pos, npos] replaces parts at positions pos in expr by parts at positions npos in new." I can't get this to work at all. If someone could explain how to do this sort of thing, using ReplacePart or otherwise, I would be most grateful. Scott Morrison scott@morrison.fl.net.au