AMATH 301 Lecture Notes - Lecture 2: Row And Column Vectors, Identity Matrix, Invertible Matrix

• School: UW
• Department: Applied Mathematics
• Course: AMATH 301
• Professor: Lowell Thompson

Document Summary

A = [1 4 1 4 3] row vector. X = [5; 2; -4; 5; 6] column vector. X(1,3) returns -4, as if we were talking about a matrix. X( [1 2 5] ) returns 5 2 6. Don"t use decimals or numbers outside of the dimension. These all work for row and column vectors. X(2) = 0 will overwrite the 2nd entry to 0. X(2:3) = [3 4] will change both entries (check sizing. Either give one number or all numbers specified to changing) A(2, 1:3) returns 2nd row, entries 1 through 3. A(1,1) = 5 changes (1,1) entry to 5. Always (row, column) eye(3) will spit out 3x3 identity matrix eye(3,5) will spit out 3x5 matrix w identity in first three columns. Ones(3) will create a 3x3 singular matrix, zeros(3) will make a 3x3 zero matrix.