ADVISORY
Please be advised that this source code is not released 
under the GNU free software licensing agreement for the 
simple reason that it is not anticipated that the program 
can be profitably developed further; it is here only to 
accompany the article by Little and Rodrguez.
The program could be characterized as a "mechanic's special", 
in that many improvements could be made, but perhaps are 
not really worth the effort.

INSTRUCTIONS
The experiment for which this program was specifically developed 
is described in the article. The data are obtained from a binding 
experiment in which a constant concentration of radioligand is 
displaced from the binding site by increasing concentrations 
of inhibitor. Data are thus the Total radioactivity, which 
is averaged for the run; and the Bound radioactivity, different 
for each concentration of inhibitor. Also necessary is a 
conversion factor, which converts between radioactivity 
and concentration, in units of nanomolar. This conversion 
factor will depend on your specific experimental procedure. The 
inhibitor concentrations are input in molar units, however. There is 
an error correction loop in the program for revising and 
correcting the data before running the optimization. Like all 
nonlinear least squares optimizations, the program requires 
initial estimates of the parameters, of which there are three: 
Inhibitory constant, Ki; total receptor concentration, Rt; 
and nonspecific binding, m. All three parameters may be 
optimized, two combinations of two parameters (Ki and Rt, or 
Ki and m), or only Ki. 
If the program does not give a result immediately, it is 
in an endless loop and must be stopped (ctrl-c) and 
new initial estimates tried. Since memory management 
is so much superior in Linux than in MS Windows, use of the 
program in Windows is not recommended.

Upon decompressing the archive, two subdirectories will 
be formed, each of which will contain a makefile. Issuing 
the corresponding make will compile and link the 
sources creating an executable for each case. 
Included with each source is a sample data archive (with 
the extension .lex) for testing your compilation.
