pub trait Fft<T: FftNum>: Length + Direction + Sync + Send {
// Required methods
fn process_with_scratch(
&self,
buffer: &mut [Complex<T>],
scratch: &mut [Complex<T>]
);
fn process_outofplace_with_scratch(
&self,
input: &mut [Complex<T>],
output: &mut [Complex<T>],
scratch: &mut [Complex<T>]
);
fn get_inplace_scratch_len(&self) -> usize;
fn get_outofplace_scratch_len(&self) -> usize;
// Provided method
fn process(&self, buffer: &mut [Complex<T>]) { ... }
}Expand description
Trait for algorithms that compute FFTs.
This trait has a few methods for computing FFTs. Its most conveinent method is process(slice).
It takes in a slice of Complex<T> and computes a FFT on that slice, in-place. It may copy the data over to internal scratch buffers
if that speeds up the computation, but the output will always end up in the same slice as the input.
Required Methods§
sourcefn process_with_scratch(
&self,
buffer: &mut [Complex<T>],
scratch: &mut [Complex<T>]
)
fn process_with_scratch( &self, buffer: &mut [Complex<T>], scratch: &mut [Complex<T>] )
Divides buffer into chunks of size self.len(), and computes a FFT on each chunk.
Uses the scratch buffer as scratch space, so the contents of scratch should be considered garbage
after calling.
§Panics
This method panics if:
buffer.len() % self.len() > 0buffer.len() < self.len()scratch.len() < self.get_inplace_scratch_len()
sourcefn process_outofplace_with_scratch(
&self,
input: &mut [Complex<T>],
output: &mut [Complex<T>],
scratch: &mut [Complex<T>]
)
fn process_outofplace_with_scratch( &self, input: &mut [Complex<T>], output: &mut [Complex<T>], scratch: &mut [Complex<T>] )
Divides input and output into chunks of size self.len(), and computes a FFT on each chunk.
This method uses both the input buffer and scratch buffer as scratch space, so the contents of both should be
considered garbage after calling.
This is a more niche way of computing a FFT. It’s useful to avoid a copy_from_slice() if you need the output
in a different buffer than the input for some reason. This happens frequently in RustFFT internals, but is probably
less common among RustFFT users.
For many FFT sizes, self.get_outofplace_scratch_len() returns 0
§Panics
This method panics if:
output.len() != input.len()input.len() % self.len() > 0input.len() < self.len()scratch.len() < self.get_outofplace_scratch_len()
sourcefn get_inplace_scratch_len(&self) -> usize
fn get_inplace_scratch_len(&self) -> usize
Returns the size of the scratch buffer required by process_with_scratch
For most FFT sizes, this method will return self.len(). For a few small sizes it will return 0, and for some special FFT sizes
(Sizes that require the use of Bluestein’s Algorithm), this may return a scratch size larger than self.len().
The returned value may change from one version of RustFFT to the next.
sourcefn get_outofplace_scratch_len(&self) -> usize
fn get_outofplace_scratch_len(&self) -> usize
Returns the size of the scratch buffer required by process_outofplace_with_scratch
For most FFT sizes, this method will return 0. For some special FFT sizes
(Sizes that require the use of Bluestein’s Algorithm), this may return a scratch size larger than self.len().
The returned value may change from one version of RustFFT to the next.
Provided Methods§
sourcefn process(&self, buffer: &mut [Complex<T>])
fn process(&self, buffer: &mut [Complex<T>])
Computes a FFT in-place.
Convenience method that allocates a Vec with the required scratch space and calls self.process_with_scratch.
If you want to re-use that allocation across multiple FFT computations, consider calling process_with_scratch instead.
§Panics
This method panics if:
buffer.len() % self.len() > 0buffer.len() < self.len()