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Custom Base Log (log x) Normally, the default log in VB use a base 10, sometimes you need to set your own base (2 for example in binary). The formula is quite simple: (log x) / (log b) "x" is the number we want the log to be and "b" is the base. Here's the code for a base 2: Public Function log2(n As Double) As Double Dim p As Double p = Log(n) / Log(2) log2 = p End Function You could of course set the base as a parameter of the function. Factorial (!n) This function let you multiply numbers by their previous. For example, factorial of 5 would be 1x2x3x4x5. In VB, we simply use a For to increment the multiplication. Here's the code: Public Function facto(n As Double) As Double Dim rep As Double Dim i As Double rep = 1 For i = 1 To n rep = rep * i Next i facto = rep End Function The E number (e) The number behind many things. Ever knew what the E number meant on your calculator, why it's giving 2,718...? It's actually simple, it can be calculated with the help of the above function (Factorial). Here's a sample of the formula: e = 1/!1 + 1/!2 + 1/3! + 1/4! + 1/5! + 1/6! + 1/7! + 1/!8.... The more operations you set, the more the e number will be precise. Note that in this code, i use the above function (Factorial). The For is used to specify the current Factorial to calculate. (!i) Public Function facto2(n As Double) As Double Dim rep As Double Dim i As Double rep = 1 For i = 1 To n rep = rep + (1 / facto(i)) Next i facto2 = rep End Function Fibonnaci The fibonnaci sequence is generated by making an addition of the previous number and the current one, just like Fibonnaci of 5 would be 1+2+3+4+5. Of course, we could use a For loop to achieve this but why not using a recursive function? In other words, it's true that the current number is the addition of the previous Fibonnaci sequence + the other one before. So we just need to call the function inside the current one indefinitly until we reach a "n" value of 1 where it's known that the result is 1. Public Function fibon(ByVal n As Byte) As Double If n < 2 Then fibon = 1 Else fibon = fibon(n - 2) + fibon(n - 1) End If End Function Root A square root can be quite simple but when it comes to cubic or more, a function might be helpful. A square root is exactly the same thing as saying: x ^ 1/2. So we can use this to calculate any root. (Short code...) Public Function racine_n(ByVal x As Double, ByVal n As Byte) As Double racine_n = x ^ (1 / n) End Function More functions and sort algorithms (Mergesort, Fusionsort, etc.) to come in future tutorials! 
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NGPixel
Lead Programmer at Pixel2Life My tutorials are mostly about PHP, MySQL, XHTML, CSS and Fireworks. 
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