Programming

Empty Matrices, Scalars, and Vectors

Although matrices are two dimensional, they do not always appear to have a rectangular shape. A 1-by-8 matrix, for example, has two dimensions yet is linear. These matrices are described in the following sections:

• The Empty Matrix

• An empty matrix has one of more dimensions that are equal to zero. A two-dimensional matrix with both dimensions equal to zero appears in MATLAB as []. The expression A = [] assigns a 0-by-0 empty matrix to A.

• Scalars

• A scalar is 1-by-1 and appears in MATLAB as a single real or complex number (e.g., 7, 583.62, -3.51, 5.46097e-14, 83+4i).

• Vectors

• A vector is 1-by-n or n-by-1, and appears in MATLAB as a row or column of real or complex numbers:

  •      Column Vector                 Row Vector
    
             53.2                  53.2 87.39 4-12i 43.9
             87.39
             4-12i
             43.9
    

Returning a Triangular Portion of a Matrix

The Empty Matrix

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