.BG
.FN solve
.TL
Solve Linear Equations and Invert Matrices
.CS
solve(a, b)
.AG a
matrix of coefficients.  Must be square and non-singular.
.AG b
optional matrix of coefficients.  If `b' is missing, the
inverse of matrix `a' is returned.
.RT
the solution `x' to the system of equations `a %*% x = b'.
.SA
`qr', `qr.coef', `chol'.
.EX
ainv <- solve(a)    #invert a
.KW array
.KW algebra
.WR
