Sage-Tips

What is the difference between A * B and A * B in MATLAB?

In the expression C=A*B , the * operator is the standard matrix product, which collects the vector dot products combining all row vectors from A with all column vectors from B. The * is used for product between two numbers from dimension 1 i.e a*b in R.

What does a * b mean in MATLAB?

C = A . * B multiplies arrays A and B by multiplying corresponding elements. The sizes of A and B must be the same or be compatible. If the sizes of A and B are compatible, then the two arrays implicitly expand to match each other.

What does AB do in MATLAB?

A\B returns a least-squares solution to the system of equations A*x= B.

Whats the difference between * and * MATLAB?

* is matrix multiplication while . * is elementwise multiplication. In order to use the first operator, the operands should obey matrix multiplication rules in terms of size.

What is meant by * in MATLAB?

It means transpose & multiply. But I think functionality varies across the new & old versions of matlab.

What does X Y mean in Matlab?

It indicates the end of a row when creating a matrix from other matrices. For example X = [1 2]; Y = [3,4]’; A = [X; Y’] gives a matrix A = [ 1 2 ] [ 3 4 ] This is called vertical concatenation which basically means forming a matrix in row by row fashion from other matrices (like the example above).

What does X Y mean in MATLAB?

How do you do inverse in MATLAB?

Description. Y = inv( X ) computes the inverse of square matrix X . X^(-1) is equivalent to inv(X) . x = A\b is computed differently than x = inv(A)*b and is recommended for solving systems of linear equations.

What is vector in MATLAB?

In MATLAB a vector is a matrix with either one row or one column. The distinction between row vectors and column vectors is essential. Many programming errors are caused by using a row vector where a column vector is required, and vice versa. In these contexts a vector is just a convenient data structure.

What is a * in MATLAB?

Description: In addition to being the symbol for matrix multiplication, the asterisk * is used as a wildcard character. MATLAB matches all characters in the name exactly except for the wildcard character * , which can match any one or more characters.

What is the difference between INV(a)*B and a\\B?

Using A\\b instead of inv (A)*b is two to three times faster, and produces residuals on the order of machine accuracy relative to the magnitude of the data. Input matrix, specified as a square matrix. If X is badly scaled or nearly singular, then the inv calculation loses numerical accuracy.

What is the difference between INV and AB in machine learning?

Using Ab instead of inv (A)*b is two to three times faster, and produces residuals on the order of machine accuracy relative to the magnitude of the data. Input matrix, specified as a square matrix. If X is badly scaled or nearly singular, then the inv calculation loses numerical accuracy.

How do you find the inverse of an equation in MATLAB?

Finding the inverse of A is equivalent to finding A\\eye (n), and hence is similar to solving n*n equations in n*n unknowns. If the number of columns, m, in B is less than n, it therefore takes less time to solve m*n equations than doing inv (A)*B which would involve n*n equations combined with a matrix multiplication.

What’s the difference between ‘A’ and ‘B’ versions?

“Usually the ‘a’ versions are more stable (…) being ‘b’ more of a pre-release of version ‘a’ of the next year [rather than an actual release], having features that have past beta but still can be improved” (and supposedly will be improved and perfected at ‘a’). But isn’t this the story with just any release?