Module basic_dsp::combined_ops

This module allows to combine certain operations into one operation. Since one many machines the speed of many DSP operations is limited by the memory bus speed this approach may result in better register and cache usage and thus decrease the pressure on the memory bus. As with all performance hints remember rule number 1: Benchmark your code. This is especially true at this very early state of the library.

With this approach we change how we operate on vectors. If you perform M operations on a vector with the length N you iterate wit hall other methods like this:

 // pseudocode:
 // for m in M:
 //  for n in N:
 //    execute m on n

with this method the pattern is changed slightly:

 // pseudocode:
 // for n in N:
 //  for m in M:
 //    execute m on n

Both variants have the same complexity however the second one is beneficial since we have increased locality this way. This should help us by making better use of registers and CPU caches.

Only operations can be combined where the result of every element in the vector is independent from any other element in the vector.

# Examples

 use std::f32::consts::PI;
 use basic_dsp::*;
 use basic_dsp::combined_ops::*;
 let a = RealTimeVector32::from_array(&[0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8]);
 let b = RealTimeVector32::from_constant(0.0, 8);
 let ops = multi_ops2(a, b);
 let ops = ops.add_ops(|a, b| {
     let a = a.scale(2.0 * PI);
     let b = b.clone_from(&a);
     let a = a.sin();
     let b = b.cos();
     let a = a.multiply_vector(&b).abs();
     let a_db = a.log(10.0).scale(10.0);
     (a_db, b)
 });
 let (a, b) = ops.get().expect("Ignoring error handling in examples");
 close(&[0.80902, 0.30902, -0.30902, -0.80902, -1.00000, -0.80902, -0.30902, 0.30902], b.data());
 close(&[-3.2282, -5.3181, -5.3181, -3.2282, -159.1199, -3.2282, -5.3181, -5.3181], a.data());

Structs

ComplexFreqIdentifier	Placeholder for a concrete vector.
ComplexTimeIdentifier	Placeholder for a concrete vector.
GenericDataIdentifier	Placeholder for a concrete vector.
MultiOperation1	A multi operation which holds a vector and records all changes which need to be done to the vectors. By calling get on the struct all operations will be executed in one run.
MultiOperation2	A multi operation which holds two vectors and records all changes which need to be done to the vectors. By calling get on the struct all operations will be executed in one run.
PreparedOperation1	An operation on one data vector which has been prepared in advance.
PreparedOperation2	An operation on two data vectors which has been prepared in advance.
RealFreqIdentifier	Placeholder for a concrete vector.
RealTimeIdentifier	Placeholder for a concrete vector.

Enums

Operation

An alternative way to define operations on a vector.

Traits

ComplexIdentifier	Operations for complex vectors which can be used in combination with multi ops or prepared ops. For a documentation of the specific operations see ComplexVectorOps.
GeneralIdentifier	Operations for all kind of vectors which can be used in combination with multi ops or prepared ops. For a documentation of the specific operations see GenericVectorOps.
Identifier	An identifier is just a placeholder for a vector used to ensure already at compile time that operations are valid.
IdentifierIter	Allows to map every vector element. with multi ops or prepared ops. For a documentation of the specific operations see VectorIter.
Offset	Offset operations to vectors in combination with multi ops or prepared ops. For a documentation of the specific operations see Offset.
RealIdentifier	Operations for real vectors which can be used on combination with multi ops or prepared ops. For a documentation of the specific operations see RealVectorOps.
Scale	Scale operations to vectors in combination with multi ops or prepared ops. For a documentation of the specific operations see Scale.
ToIdentifier	Trait which defines the relation between a vector and an identifier.

Functions

multi_ops1	Creates a new multi operation for one vectors.
multi_ops2	Creates a new multi operation for two vectors.
prepare1	Prepares an operation with one input and one output.
prepare2	Prepares an operation with two inputs and two outputs.