Mathematics

Adding and Subtracting Matrices

Addition and subtraction of matrices is defined just as it is for arrays, element-by-element. Adding A to B and then subtracting A from the result recovers B.

• A = pascal(3);
  B = magic(3);
  X = A + B
  
  X =
         9     2     7
         4     7    10
         5    12     8
  
  Y = X - A
  
  Y =
         8     1     6
         3     5     7
         4     9     2
  

Addition and subtraction require both matrices to have the same dimension, or one of them be a scalar. If the dimensions are incompatible, an error results.

• C = fix(10*rand(3,2))
  X = A + C
  Error using ==> +
  Matrix dimensions must agree.
  
  w = v + s
  
  w = 
         9     7     6
  

Creating Matrices

Vector Products and Transpose

© 1994-2005 The MathWorks, Inc.