My sincere thanks to all who responded. My question really boiled down to:
How to extract an arbitrary vector form a matrix?
The nearly universal answer is
vector.of.matrix.elements <- matrix.of.data[cbind(row.index, column.index)]
where vector.of.matrix is the vector of matrix elements desired,
matrix.of.data, is the matrix from which the elements are to be extracted,
row.index and column.index are each vectors of the same length that specify
which elements to extract. Alternatively, these may be thought of as two
columns of a matrix, which is exactly what cbind() does.
I wish to thank: Brad Biggerstaff, Bill Dunlap, Tony Plate, Sam Buttrey,
Steve McKinney, Andy Liaw, Patrick Burns (whose book I have but obviously
haven't yet completely absorbed), Scott Seleska, Nick Ellis, and Erin
Hodges for their useful, timely, informative replies.
All th ebest,
Kim Elmore
Kim Elmore, Ph.D.
University of Oklahoma
Cooperative Institute for Mesoscale Meteorological Studies
"All of weather is divided into three parts: Yes, No, and Maybe. The
greatest of these is Maybe" The original Latin appears to be garbled.
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