What are Math Functions
Math functions in VB programming are functions that process one or more numbers and return a value. They are no different functions in mathematics. Though we can create customized math functions, we can save time by using a score of built-in math functions in Visual Basic 2010.
14.2 The Exp function
The Exp of a number x is the exponential value of x, i.e. ex.
The syntax is:
14.3 The Fix Function
The Fix function truncates the decimal part of a positive number and returns the largest integer smaller than the number. However, when the number is negative, it will return the smallest integer larger than the number. For example, Fix(9.2)=9 but Fix(-9.4)=-9
Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click Dim num1, num2 As Single num1 = TextBox1.Text num2 = Fix(num1) Label1.Text = num2 End Sub
14.4 The Int Function
The Int is a function that converts a number into an integer by truncating its decimal part and the resulting integer is the largest integer that is smaller than the number. For example
Int(2.4)=2, Int(6.9)=6 , Int(-5.7)=-6, Int(-99.8)=-100
14.5 The Log Function
The Log function is the function that returns the natural logarithm of a number. For example, Log(10)=2.302585
Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click Dim num1, num2 As Single num1 = TextBox1.Text num2 = Math.Log(num1) Label1.Text = num2 End Sub
* The logarithm of num1 will be displayed on label1
14.6 The Rnd( ) Function
The Rnd function returns a random value between 0 and 1. Random numbers often need to be converted into integers in programming. For example, if we wish to obtain a random output of 6 integers ranging from 1 to 6, which makes the program behaves like a virtual dice, we need to convert the random numbers to integers using the formula Int(Rnd*6)+1.
Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click Dim num as integer Num=Int(Rnd()*6)+1 Label1.Text=Num End Sub
In this example, Int(Rnd*6) will generate a random integer between 0 and 5 because the function Int truncates the decimal part of the random number and returns an integer. After adding 1, you will get a random number between 1 and 6 every time you click the command button. For example, let say the random number generated is 0.98, after multiplying it by 6, it becomes 5.88, and using the integer function Int(5.88) will convert the number to 5, and after adding 1 you will get 6.
14.7 The Round Function
The Round function rounds up a number to a certain number of decimal places. The syntax is Round (n, m) which means to round a number n to m decimal places. For example,
Math.Round (7.2567, 2) =7.26
Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click Dim num1, num2 As Single num1 = TextBox1.Text num2 = Math.Round(num1, 2) Label1.Text = num2 End Sub
* The Math keyword indicates that the Round function belongs to the Math class.