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(Q:) ReplacePart + SubMatrix replacement


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


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