Language Reference

DIAG Function

creates a diagonal matrix

DIAG( argument)

where argument can be either a numeric square matrix or a vector.

If argument is a square matrix, the DIAG function creates a matrix with diagonal elements equal to the corresponding diagonal elements. All off-diagonal elements in the new matrix are zeros.

If argument is a vector, the DIAG function creates a matrix with diagonal elements that are the values in the vector. All off-diagonal elements are zeros.

For example, the following statements produce the matrix , as shown:

  
      a={4 3, 
         2 1}; 
      c=diag(a);
 

  
                 C             2 rows      2 cols    (numeric) 
  
                                      4         0 
                                      0         1
 

The following statements produce the matrix , as shown:

  
      b={1 2 3}; 
      d=diag(b);
 

  
                 D             3 rows      3 cols    (numeric) 
  
                                 1         0         0 
                                 0         2         0 
                                 0         0         3