metad_nll

metad_nll(guess, nR_S1, nR_S2, nRatings, d1, t1c1, s, parameters=None, prior=False)

Evaluate the negative log-likelihood of the parameters given the data. This function is used in the optimization process to fit the meta-d model.

Parameters:

guess

guess[0] = meta d’ guess[1:end] = type-2 criteria locations

nR_S1, nR_S2

These are vectors containing the total number of responses in each response category, conditional on presentation of S1 and S2.

nRatings

Numbers of ratings.

d1

d prime.

t1c1

The type-1 criterion.

s

Ratio of standard deviations for type 1 distributions as: s = np.std(S1) / np.std(S2). If not specified, s is set to a default value of 1. For most purposes, it is recommended to set s=1. See http://www.columbia.edu/~bsm2105/type2sdt for further discussion.

Returns:

logLfloat

The negative log-likelihood of the parameters given the data.