Basics of MATLAB and Beyond

1.3 MatricesThe basic object that matlab deals with is a matrix. A matrix is anarray of numbers. For example the following are matrices:⎛ ⎞⎛⎞12 3 9⎝ −1200 0 1e6 ⎠ , ( 1 2 3 4 5 ) i, ⎜ −i⎟⎝ i ⎠ , 42.0.1 pi 1/3−iThe size of a matrix is the number of rows by the number of columns.The first matrix is a 3 × 3 matrix. The (2,3)-element is one million—1e6stands for 1 × 10 6 —and the (3,2)-element is pi = π =3.14159 ... .The second matrix is a row-vector, the third matrix is a column-vectorcontaining the number i, which is a pre-defined matlab variable equalto the square root of −1. The last matrix is a 1 × 1 matrix, also calleda scalar.1.4 VariablesVariables in matlab are named objects that are assigned using theequals sign = . They are limited to 31 characters and can containupper and lowercase letters, any number of ‘_’ characters, and numerals.They may not start with a numeral. matlab is case sensitive: Aand a are different variables. The following are valid matlab variableassignments:a = 1speed = 1500BeamFormerOutput_Type1 = v*Q*v’name = ’John Smith’These are invalid assignments:2for1 = ’yes’first one = 1To assign a variable without getting an echo from matlab end theassignment with a semi-colon ;. Try typing the following:a = 2b = 3;c = a+b;d = c/2;dwhowhosclearwhoc○ 2000 by CRC Press LLC