f = 

     General model:
     f(x) = a+b*(1./(1+exp(-d*(x-c))))
     Coefficients (with 95% confidence bounds):
       a =      -7.319  (-7.862, -6.776)
       b =       2.432  (1.64, 3.224)
       c =      -2.659  (-2.887, -2.432)
       d =       3.283  (0.7235, 5.842)

fgof = 

  struct with fields:

           sse: 4.9334e+03
       rsquare: 0.1681
           dfe: 1135
    adjrsquare: 0.1659
          rmse: 2.0848


fout = 

  struct with fields:

           numobs: 1139
         numparam: 4
        residuals: [1139×1 double]
         Jacobian: [1139×4 double]
         exitflag: 3
    firstorderopt: 2.1528
       iterations: 21
        funcCount: 110
     cgiterations: 0
        algorithm: 'trust-region-reflective'
         stepsize: 0.0103
          message: 'Success, but fitting stopped because change in residuals less than tolerance (TolFun).'
