(Q:) ReplacePart + SubMatrix replacement

*To*: mathgroup at smc.vnet.net*Subject*: [mg7033] (Q:) ReplacePart + SubMatrix replacement*From*: "m.r." <schaferk at communique.net>*Date*: Fri, 2 May 1997 21:30:57 -0400 (EDT)*Organization*: Communique Inc.*Sender*: owner-wri-mathgroup at wolfram.com

greetings: Mma3.0 has added a form of ReplacePart not found in Mma2.2.2: ?ReplacePart[expr,new,pos,npos] ReplacePart[expr,new,pos,npos] replaces parts at positions pos in expr by parts at positions npos in new. For A,B n-by-n, matrices, K non empty subset of CartesianProduct[Range[n],Range[n]] one can use ReplacePart[A,B,K,{1,1}] to replace the block A[[K]] with B[[1,1]]. (no problem) what i wish ( though perhaps unrealistically) is for ReplacePart[A,B,K,K] to replace the block A[[K]] with the block B[[K]]. am i misreading the above usage message for ReplacePart? if so, how does one do a simple block replace in "one fell swoop"? sincerely. m. r. email replies to schaferk at tennessee.nrlssc.navy.mil