关于R行列式det()的问题

hollow

a <- 1:4
b <- cbind(a, a+1, a+2, a+3) ^ 2
det(b)为什么会求不到整数 det(b)应当是0
求指点

doby

可能跟数组的大小有关。。你看看这个链接有没有帮助 我还是没太理解
http://stackoverflow.com/questio ... t-of-a-matrix-in-r#
For large matrices the determinant can be too large or too small and overflow the double precision. The determinant is the product of the eigenvalues: for instance, if they are all .0001, your matrix is invertible, but the determinant is 1e-400, which is too small, and can only be represented as 0.

You can look at the logarithm of the determinant instead,

determinant(R, logarithm=TRUE)
or, directly, the eigenvalues

eigen(R, only.values=TRUE)