Last data update: 2014.03.03
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R: Threshold and slope of estimated psychometric function
threshold_slope | R Documentation |
Threshold and slope of estimated psychometric function
Description
Finds the approximate value of x (=x_th) for which the value of the psychometric function is equal thresh and the approximate value of slope in x_th
Usage
threshold_slope( pfit, xfit, thresh = 0.5 )
Arguments
pfit |
estimated values of the psychometric function
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xfit |
stimulus levels in which the function was estimated
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thresh |
value for which to estimate threshold; default is 0.5
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Value
value |
Object with 2 elements:
x_th: estimated threshold
slope: estimated value of slope, i.e. derivative of pfit at x_th
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Examples
data( "01_Miranda" )
xnew = 1.2 * (0:999)/999+0.1
h = 0.2959
fit <- locglmfit( xnew, example01$r, example01$m, example01$x, h )
value <- threshold_slope( fit$pfit , xnew )
Results
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