Linear Algebra Flashcards
1
Q
Scalar Number
A
Single number.
2
Q
Vector
A
Array of numbers.
3
Q
Matrix
A
2d array of numbers (A[i:] is the i’th row, A[:j] is the j’th column).
4
Q
Tensor
A
Array with more than two axes (A_i,j,k for example).
5
Q
Transpose
A
Mirror of vector/matrix
6
Q
Linear Transformation
A
A function from one vector space to another that respects the underlying (linear) structure of each vector space.
A_x = B
7
Q
Identity Matrix
A
1 for every n=n.
8
Q
Inverse
A
A -> A^-1
9
Q
Norms
A
Used for measuring the size of a vector.
10
Q
L^p Norm
A
The equation that’s used to measure the size of a vector.
||x||p = ( ∑i|x_i|p)^1/p
11
Q
L^2 Norm
A
||x||2 = ( ∑i|x_i|p)^1/p = √ ∑i|x_i|^2
12
Q
L^1 Norm
A
||x|| = ∑i|x_i|
13
Q
L^∞
A
||x||∞ = max_i |x_i |
