A copy of the paper can be downloaded here .
This research was sponsored by the National Research Foundation in South Africa, under grant FA2005032300018.
The paper is concerned with the numerical solution of
-y''(x) + p(x) y = E y,on the real line (assuming decaying boundary conditions).
Below are some MATLAB M-files, some of which are listed in the paper, for computing spectra of various potentials p(x) . Download the main code and execute by typing its name in MATLAB. The following are auxilliary codes from DMSUITE that should be downloaded once. (For the complete DMSUITE collection, see the local site or the MathWorks site).
The code of Table 2 can be combined with MATLAB's fminsearch to minimize the distance between E0 and E1. This computes the critical value of a=3.169036141. Main M-file: finda.m Auxilliary: acrit.m
This is the computation of the real spectrum of the QES potential p(z) = -z^4-2bz^2-6iz , which reproduces Figure 3 of the paper. The code is omitted in the paper, but for the sake of numbering we'll assume it was given in a Table 3. M-file: table3.m