Prof. Powershell

Easy as PI

Math class is in session with these Powershell tricks.

• By Jeffery Hicks
• 08/13/2008

First, the object has fields for the constants pi and e:

PS C:\> [math]::e
2.71828182845905
PS C:\> [math]::pi
3.14159265358979

Sure you could create a variable for pi using 3.14, but this is more fun:

PS C:\> $r=2.3456
PS C:\> [math]::pi*($r*$r)
17.2845381146072

The [Math] class contains all of your familiar trigonometry functions like sin, cos and tan. Although I don't do much trig these days and probably not in PowerShell. But you may find these methods useful.

Return an absolute value:

PS C:\> [math]::abs(-4)
4

Return a square root:

PS C:\> [math]::sqrt(64)
8

Return one number raised to another number such as 2 to the 8th power:

PS C:\> [math]::pow(2,8)
256

Using this method I could rewrite my first example:

PS C:\> [math]::pi*[math]::pow($r,2)
17.2845381146072

But I find it just as easy to write ($r*$r).

One math related task you are likely to use are random numbers, perhaps as part of a password generating routine or maybe even an office lottery. To get random numbers use the System.Random class. You'll find it easier to create an object using the New-Object cmdlet:

PS C:\> $random=new-object system.random

You can either generate a random number that is less than a given value using the Next() method:

PS C:\> $random.next(10)
2

This value will always be positive. Or return a value within a given range by specifying a lower and upper limit:

PS C:\> $random.next(1024,2048)
1873

You can learn more about the math class by reviewing the MSDN documentation.