Built in recursive function in matlab, MATLAB in Mathematics

Built in recursive function in MATLAB:

We have seen that the built-in function in MATLAB to compute factorials, termed as the factorial and we know how to implement the iterative definition by using a running product. Now we will rather than write a recursive function known as the fact. The function will receive an integer n, which for ease will suppose is a positive integer, and will compute n! just by using the recursive definition given:

 

1287_Built in recursive function in matlab.png

The function computes one value, by using an if-else statement to select between the base and general cases. When the value passed to the function is 1, the function returns 1 as1! become equal to 1. Or else, the common case applies. According to definition, the factorial of n, that is what this function is computing, is defined as n multiplied by the factorial of (n-1). Therefore, the function assigns   n * fact(n-1) to the output argument.

How does this work? Precisely the way the illustration was sketched for 3!. Let's trace what would take place if the integer 3 is passed to the function:

fact(3) tries to assign 3 * fact(2)

fact(2) tries to assign 2 * fact(1)

fact(1) assigns 1

fact(2) assigns 2

fact(3) assigns 6

Whenever the function is initially called, 3 is not equivalent to 1, therefore the statement

facn = n * fact(n-1);

is executed. This will try to assign the value of 3 * fact(2) to  facn, but this expression cannot be computed yet and hence value cannot be assigned yet as first the value of fact(2) should be found. Therefore, the assignment statement has been interrupted by a recursive call to the fact function. The call to the function fact (2) answers in a try to assign 2 * fact(1), but again this expression cannot so far be computed. Later, the call to the function fact(1) answers in a complete execution of an assignment statement as it just assigns 1. The base case has been reached once, and then the assignment statements which were interrupted can be computed, in the reverse order.

Posted Date: 10/22/2012 1:31:37 AM | Location : United States







Related Discussions:- Built in recursive function in matlab, Assignment Help, Ask Question on Built in recursive function in matlab, Get Answer, Expert's Help, Built in recursive function in matlab Discussions

Write discussion on Built in recursive function in matlab
Your posts are moderated
Related Questions
Plot Functions: Faraway, we have plotted to generate two-dimensional plots and bar to generate bar charts. We have seen how to clear the Figure Window by using clf, and how to

Customizing Plots : There are numerous ways to customize figures in the Figure Window. On clicking the Plot Tools icon will bring up the Property Editor & Plot Browser, with ma

Function xlsread - file function: The function xlsread will read from the spreadsheet file. For illustration, to read from file just generated: >> ssnums = xlsread('ranexc

Functions to create special matrices: The MATLAB also has various functions which create special matrices. For illustration, the zeros function generates a matrix of all zeros

Illustration of Writing variables to a file: For illustration, in the below session in the Command Window, 3 variables are generated; these are then exhibited using who. Then,

strvcat function - concatenation: The function strvcat will concatenate it vertically, that means that it will generate a column vector of the strings.   >> strvcat(fir

Program of built-in factorial function: Calling this function yields similar result as the built-in factorial function: >> fact(5) ans =   120 >> factorial(

Strings as Vectors: The Strings are considered as vectors of characters-or in another words, a vector in which each and every element is a single character-so numerous vector

bar and barh functions: For a matrix, the bar and barh functions will group altogether the values in each and every row. The illustration is as shown: rm = randint(2,4,[1

Nested IF-ELSE statements: The if-else statement is used to select between the two statements. In order to select from more than two statements, the if-else statements can als