f = 

     General model:
     f(x) = a+b*(1./(1+exp(-d*(x-c))))
     Coefficients (with 95% confidence bounds):
       a =      -9.833  (-64.65, 44.98)
       b =          10  (-56.27, 76.27)
       c =       -3.33  (-13.74, 7.084)
       d =      0.8347  (-3.787, 5.456)

fgof = 

  struct with fields:

           sse: 1.7280e+04
       rsquare: 0.0503
           dfe: 1081
    adjrsquare: 0.0476
          rmse: 3.9981


fout = 

  struct with fields:

           numobs: 1085
         numparam: 4
        residuals: [1085×1 double]
         Jacobian: [1085×4 double]
         exitflag: 3
    firstorderopt: 0.2699
       iterations: 17
        funcCount: 90
     cgiterations: 0
        algorithm: 'trust-region-reflective'
         stepsize: 0.0542
          message: 'Success, but fitting stopped because change in residuals less than tolerance (TolFun).'
