# SDL_logf Compute the natural logarithm of `x`. ## Header File Defined in [<SDL3/SDL_stdinc.h>](https://github.com/libsdl-org/SDL/blob/main/include/SDL3/SDL_stdinc.h) ## Syntax ```c float SDL_logf(float x); ``` ## Function Parameters | | | | | ----- | ----- | --------------------------------------------- | | float | **x** | floating point value. Must be greater than 0. | ## Return Value (float) Returns the natural logarithm of `x`. ## Remarks Domain: `0 < x <= INF` Range: `-INF <= y <= INF` It is an error for `x` to be less than or equal to 0. This function operates on single-precision floating point values, use [SDL_log](SDL_log) for double-precision floats. This function may use a different approximation across different versions, platforms and configurations. i.e, it can return a different value given the same input on different machines or operating systems, or if SDL is updated. ## Thread Safety It is safe to call this function from any thread. ## Version This function is available since SDL 3.2.0. ## See Also - [SDL_log](SDL_log) - [SDL_expf](SDL_expf) ---- [CategoryAPI](CategoryAPI), [CategoryAPIFunction](CategoryAPIFunction), [CategoryStdinc](CategoryStdinc)