Returns the log base 2 of n, the number 2 must be powered by to equal n.



Argument Description
n The input value.

Returns: Real


This function basically asks "how many 2's do you need to multiply to get n?". A common example of use in programming would be to calculate the number of bits that are needed to represent a number. To do this we calculate the log2(x) of the number, round it down and add 1 - for example log2(100) returns 6.643856, which rounded down is 6, to which we add one and it gives us 7. So we need 7 bits to represent 100. It can also be used for describing exponential growth or decay, and is often called a binary logarithm.


colourbits = floor(log2(colour)) - 1;

The above code stores the number of bits needed to represent the value stored in the variable "colour".

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