asa_call()
This function is deprecated and should not be used. It has been replaced by cw_angular_spectrum.
Description: This function is a gateway to the C++ function that calculates the 3D pressure using the Angular Spectrum Approach.
Usage
pressure = asa_call(p0, z0, z, medium, nfft, delta, type, f0);
Arguments
- p0 matrix of size [nx,ny], input pressure or velocity source.
- z0 scalar, location of the source pressure plane.
- z vector, location of destination planes.
- medium The medium in which this calculation will occur.
- nfft FFT grid number. Must be greater than the largest dimensions of the input pressure matrix. See notes for details on choosing this value.
- delta scalar, spatial sampling interval in meters.
- type Selection for different choices of ASA method; default is 'Pa'.
- 'P' Spectral propagator and pressure source without angular restriction.
- 'Pa' Spectral propagator and pressure source with angular restriction. (This is the default)
- 'V' Spectral propagator and velocity source without angular restriction.
- 'Va' Spectral propagator and velocity source with angular restriction.
- 'p' Spatial propagator and pressure source without angular restriction.
- 'v' Spatial propagator and velocity source without angular restriction.
- f0 Excitation frequency of the source wave.
Output Parameters
- fftpress matrix of size [ nx ny nz ], calculated pressure.
Notes
To choose the number of FFT terms to use, the simplest method is to zero-pad the source pressure and increase the number of terms until an acceptable error is reached. Numbers of terms that are powers of two (e.g. 512, 1024) usually result in the fastest calculations.