Home
Julia

prevpow

prevpow(a, x)

The largest a^n not greater than x, where n is a non-negative integer. a must be greater than 1, and x must not be less than 1.

Examples

Find the largest power of a not greater than x:
```
julia> prevpow(2, 10)
8
```
This example calculates the largest power of 2 that is not greater than 10.
Calculate the previous power of a larger number:
```
julia> prevpow(3, 20)
9
```
It returns the largest power of 3 that is not greater than 20.
Handle edge cases when x is equal to a^n:
```
julia> prevpow(4, 64)
64
```
It correctly handles the case where x is equal to a^n.

Common mistake example:

julia> prevpow(1, 5)
ERROR: ArgumentError: `a` must be greater than 1

In this example, the value of a is less than 1, which is not allowed. Make sure to provide a value of a that is greater than 1 to avoid such errors.

See Also

User Contributed Notes

Add a Note

The format of note supported is markdown, use triple backtick to start and end a code block.