The expression is a matrix and the statement group X is repeated as many times as the number of elements in the columns of the expression matrix. | Attia John Okyere. Control Statements . Electronics and Circuit Analysis using MATLAB. Ed. John Okyere Attia Boca Raton CRC Press LLC 1999 1999 by CRC PRESS LLC CHAPTER THREE CONTROL STATEMENTS FOR LOOPS FOR loops allow a statement or group of statements to be repeated a fixed number of times. The general form of a for loop is for index expression statement group X end The expression is a matrix and the statement group X is repeated as many times as the number of elements in the columns of the expression matrix. The index takes on the elemental values in the matrix expression. Usually the expression is something like m n or m i n where m is the beginning value n the ending value and i is the increment. Suppose we would like to find the squares of all the integers starting from 1 to 100. We could use the following statements to solve the problem sum 0 for i 1 100 sum sum iA2 end sum For loops can be nested and it is recommended that the loop be indented for readability. Suppose we want to fill 10-by-20 matrix b with an element value equal to unity the following statements can be used to perform the operation. n 10 number of rows m 20 number of columns for i 1 n for j 1 m b i j 1 semicolon suppresses printing in the loop end end 1999 CRC Press LLC b display the result It is important to note that each for statement group must end with the word end. The following program illustrates the use of a for loop. Example The horizontal displacement x t and vertical displacement y t are given with respect to time t as x t 2t y t sin t For t 0 to 10 ms determine the values of x t and y t . Use the values to plot x t versus y t . Solution MATLAB Script for i 0 10 x i 1 2 i y i 1 2 sin i end plot x y Figure shows the plots of x t and y t . 1999 CRC Press .
