log2(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".