It’s an identity matrix. You multiple a vector with it and the result is still the same (identical) vector
Comment on identity theft
neidu3@sh.itjust.works 1 month ago
Could one of you scholars please explain the joke for us smoothbrains who don’t get it? All I see is a matrix.
lugal@lemmy.dbzer0.com 1 month ago
Gustephan@lemmy.world 1 month ago
Eigen see how this is confusing, I don’t get it either
pseudo@jlai.lu 1 month ago
That matrix of zeros with one in diagonal is called the matrix of identity.
It is famous because when doing multiplication on matrix or vector, it acts likes 1 on “normal” number: 1 times x is x Identity times anyMatrix is anyMatrix.fallingcats@discuss.tchncs.de 1 month ago
Wouldn’t you need to put
anyMatrix
first, since matrix multiplication isn’t commutative?pseudo@jlai.lu 1 month ago
You are right. I will correct it.
fallingcats@discuss.tchncs.de 1 month ago
No I just tried it and I was wrong, it seems like it doesn’t matter for the I’d matrix specifically
MBM@lemmings.world 1 month ago
Huh? Identity times anyMatrix is also anyMatrix. The matrix just has to have the right dimensions
Saleh@feddit.org 1 month ago
You multiply vectors and matrizes row by column.
So for any matrix the fitting identity matrix multiplies each row on the relevant position by one and puts it into a column.
The matrix remains the same.
See example 5 here: www.geeksforgeeks.org/identity-matrix/
zqwzzle@lemmy.ca 1 month ago
A square matrix with the ones in the diagonal is called the identity matrix