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• Examples
  • Experiment 1
  • Experiment 2
  • Experiment 3
  • Experiment 4
  • Experiment 5
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This is a Python library that implements the methods described in the article Controlling precedence in sequential stimulus presentation with Euler tours, available on PsyArXiv. It contains two files:

1. euler.py: contains all functionality for generating sequences of stimuli. Add this file to your working directory and import it using import euler to use the library.
2. sequence.py: contains examples of generating sequences of stimuli for various experimental parameters. Run it by calling python sequence.py on the command line.

The file sequence.py contains a number of examples on how to use the library to generate sequences for various experimental parameters. These example experiment setups and corresponding generated sequences are included below.

Generate sequence for four stimuli with each pair occurring once, including repeated stimuli. These are the default settings, so no need to specify any parameters for this experiment.

Input:

experiment = euler.Euler()
print(experiment.get_sequence())

Output:

['3', '0', '0', '1', '2', '1', '3', '1', '1', '0', '2', '3', '3', '2', '2', '0', '3']

Generate sequence for 3 stimuli without same-stimulus pairs, and with catch trials occurring on average every 1/4 stims. Force the sequence to start at stimulus 0.

Input:

experiment = euler.Euler(stimuli=3, catch_frequency=0.25, stim_repeat=False)
print(experiment.get_sequence(0))

Output:

['0', '2', '1', '0', 'C', '0', '1', 'C', '1', '2', 'C', '2', '0']

Generate sequence with equal catch trial precedence, and each pair of stimuli twice.

Input:

experiment = euler.Euler(catch_to_all=True, pair_repeats=2)
print(experiment.get_sequence())

Output:

['1', '2', '0', '0', '1', '3', '3', 'C', '0', '1', '1', '2', '3', '3', 'C', '2', 'C', '1', '0', '2', '0', 'C', '0', 'C', '3', '1', 'C', '1', '0', '0', '3', '0', '2', '2', '3', '2', '2', '1', '1', 'C', '2', '1', '3', '2', 'C', '3', '0', '3', '1']

Generate sequence by stitching two sequences for five stimuli together. Repeating sequences (exp. 4) is different from repeating pairs (exp. 3): it guarantees that all pairs have occurred exactly once in the first half.

Input:

experiment = euler.Euler(stimuli=5, seq_repeats=2)
print(experiment.get_sequence())

Output:

['2', '1', '0', '3', '3', '0', '2', '2', '0', '1', '2', '4', '3', '4', '4', '2', '3', '1', '4', '0', '0', '4', '1', '1', '3', '2', '2', '4', '4', '1', '3', '3', '1', '1', '4', '0', '3', '4', '3', '2', '3', '0', '0', '4', '2', '1', '0', '1', '2', '0', '2']

Generate sequence for four stimuli with each triplet occurring once.

Input:

experiment = euler.Euler(triplets=True, stim_repeat=False)
print(experiment.get_sequence())

Output:

['0', '1', '2', '3', '0', '2', '3', '2', '0', '2', '0', '1', '3', '2', '1', '3', '0', '3', '2', '3', '1', '3', '1', '0', '3', '1', '2', '1', '2', '0', '3', '0', '1', '0', '2', '1', '0', '1']

Jacob Bakermans - jacob.bakermans [at] gmail.com

Project Link: https://github.com/jbakermans/stimulus-history-euler-tours