>Psychtoolbox>Psychometric

[alpha,beta,thresh92] = FitWeibAlphTAFC(inputs,nCorrect,nError,alpha0,beta0)

Maximum likelihood fit of a Weibull function to psychometric data,
search only on alpha with fixed beta as passed.

Requires the optimization toolbox.

INPUTS:

inputs: contains the input levels
nCorrect: contains the number of yes responses at
the corresponding input inputs
nError: contains the number of no responses at
the corresponding input inputs
alpha0: Initial guess for alpha, empty for default [1].
beta0: Value for beta

OUTPUTS:

alpha Weibull alpha parameter
beta Weibull beta parameter
thresh92 92% percent correct threshold

See also: FitWeibTAFC, FitFitWeibYN, FitCumNormYN, FitLogitYN

8/25/94 dhb, ccc Cleaned comments, return 92% correct threshold.
2/8/97 dhb Added check for optimization toolbox.
4/26/97 dhb Change threshold to thresh92.
4/18/02 dhb Fix reference to undefined variable ‘levels’.
dhb Suppress warnings in calls to optimization toolbox.
3/5/05 dhb Update for optimization toolbox version 2.