created at April 8, 2021

Creating a matrix

to create a matrix:

create matrix by listing all it's elements in figure brackets and separating rows with semicolon:

as you can see, number of elements in rows can be different. In this case number of columns for a such matrix will be equal to the longest row's length. Missed element positions will be filled with zeros.

using matrices in calculations:

  • a11 = A[0, 0] - indexing matrix element.
  • A1 = A[1, ] - A1 will be matrix, created from matrix A 2nd row.
  • A2 = A[ , 2] - A2 will be matrix, created from matrix A 3-rd column.

matrix can be used in expressions without indexes. It can be multiplied by a number or by another matrix, transposed, inversed etc.

transpose matrix:

inverse matrix:

matrix determinant can be calculated as det(A).