Sampling Euler tours for uniform stimulus history

Table of Contents

• About
• Examples
  • Experiment 1
  • Experiment 2
  • Experiment 3
  • Experiment 4
  • Experiment 5
• Contact

About

This is a Python library that implements the methods described in the article Controlling precedence in sequential stimulus presentation with Euler tours. 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.

Examples

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.

Experiment 1

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']

Experiment 2

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']

Experiment 3

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']

Experiment 4

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']

Experiment 5

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']

Contact

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

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