odified C code L-BFGS-B-C, and so has 
    a slightly different calling syntax than previous versions.
 
   The minimization problem that it solves is:
        min_x  f(x)     subject to   l &lt;= x &lt;= u
 
  'fcn' is a function handle that accepts an input, 'x',
    and returns two outputs, 'f' (function value), and 'g' (function gradient).
 
  'l' and 'u' are column-vectors of constraints. Set their values to Inf
    if you want to ignore them. (You can set some values to Inf, but keep
    others enforc