Determinant and permanent: Difference between revisions
Added R.
ReeceGoding (talk | contribs) (Added R.) |
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The second matrix above is that used in the Tcl example. The third matrix is from the J language example. Note that the determinant seems to be 'exact' using this method of calculation without needing to resort to other than Pythons default numbers.
=={{header|R}}==
R has matrix algebra built in, so we do not need to import anything when calculating the determinant. However, we will use a library to generate the permutations of 1:n.
<lang R>library(combinat)
perm <- function(A)
{
stopifnot(is.matrix(A))
dimensions <- dim(A)
n <- dimensions[1]
if(any(dimensions != n)) stop("Matrix is not square.")
if(n < 1) stop("Matrix has a dimension of size 0.")
sum(sapply(combinat::permn(n), function(sigma) prod(sapply(1:n, function(i) A[i, sigma[i]]))))
}
#We copy our test cases from the Python example.
testData <- list("Test 1" = rbind(c(1, 2), c(3, 4)),
"Test 2" = rbind(c(1, 2, 3, 4), c(4, 5, 6, 7), c(7, 8, 9, 10), c(10, 11, 12, 13)),
"Test 3" = rbind(c(0, 1, 2, 3, 4), c(5, 6, 7, 8, 9), c(10, 11, 12, 13, 14),
c(15, 16, 17, 18, 19), c(20, 21, 22, 23, 24)))
print(sapply(testData, function(x) list(Determinant = det(x), Permanent = perm(x))))</lang>
{{out}}
<pre> Test 1 Test 2 Test 3
Determinant -2 1.131522e-29 0
Permanent 10 29556 6778800</pre>
=={{header|Racket}}==
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