9.6 Determinant of a Real Symmetric Matrix

SymDet

## function (SymMat) 
## {
##     n = dim(SymMat)[1]
##     Det = SymMat[1, 1]
##     if (n > 1) {
##         L = SymMat
##         for (i in 1:n) {
##             for (j in 1:i) {
##                 if (j > 1) 
##                   for (k in 1:(j - 1)) L[i, j] = L[i, j] - L[i, 
##                     k] * L[j, k] * L[k, k]
##                 if (j < i) 
##                   L[i, j] = L[i, j]/L[j, j]
##             }
##         }
##         for (i in 2:n) Det = Det * L[i, i]
##     }
##     return(Det)
## }
## <bytecode: 0x000001e2b39fc308>
## <environment: namespace:math>

SymDet(M)

## [1] 33

det(M)

## [1] 33