A Discrete Dipole Approximation Solver Based on the COCG-FFT Algorithm and Its Application to Microwave Breast Imaging

Table 1

Computation times (s).

	Direct		COCG		COCR		COCG-FFT			COCR-FFT
#dipoles	MATLAB	C++ (Armadillo)	MATLAB	C++ (Armadillo)	MATLAB	C++ (Armadillo)	MATLAB	C++		MATLAB	C++
								Armadillo	FFTW		Armadillo	FFTW
441	0.0045	0.0540	0.0029	0.0033	0.0034	0.0037	0.0413	0.0029	0.0069	0.04123	0.0030	0.0069
1681	0.1790	2.1660	0.0790	0.0632	0.0830	0.0680	0.1869	0.0565	0.0600	0.1851	0.0589	0.0549
6561	5.3340	57.8030	1.5296	1.4693	1.6020	1.5353	1.4603	1.2336	0.6431	1.4410	1.3612	0.6512