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  • Description
  • Computes the Wilcoxon test (non-parametric test) on TF files (.tf). It allows to compare 2 conditions (or the difference between 2 conditions) with paired subjects.

  • Usage
  • tfavgwilcox [+fdr]
    with :

    • option :
      +fdr : computes False Detection Rate (FDR) after the statistical test. It creates a TF file with a mask of the statistical results (Z) with the computed FDR. This requires a probability (p) threshold value.

    This program uses an interactive input.The questions are as follows (questions (program) are italic, answers (user) are bold):
    Number of conditions (2 conditions or 1 for difference file) :
    2
    Number of files per condition :
    1
    Baseline correction: none (0), mean (1) or median (2) on a time-window ? (0/1/2) :
    1
    0: no baseline correction
    1: the mean value between start and stop latencies will be used
    2: the median value between start and stop latencies will be used
    if baseline correction ≠ 0
    Start latency of baseline (in ms) :
    -400
    Stop latency of baseline (in ms) :
    -100
    Substract(1) or divide(2) by baseline ? (1/2)
    1
    1: the baseline value is substracted from the original data
    2: the original data are divided by the baseline value
    FDR threshold :
    0.05
    It defines the probability (p) threshold value to be used for masking the statistical results (Z) by the threshold FDR statistics.
    Only if +fdr option is specified.
    Input file name (with extension) 1 in condition 1 :
    tf_file1cond1.avg.tf
    Input file name (with extension) 2 in condition 1 :
    tf_file2cond1.avg.tf
    ...
    Input file name (with extension) 1 in condition 2 :
    tf_file1cond2.avg.tf
    ...
    Input file name (with extension) 10 in condition 0 :
    tf_file10cond2.avg.tf

    Output file prefix (no extension) :
    tf_wilcox

  • Fields of parameter file and example

  • Examples

  • Comments
    1. The programs creates 2 TF files : .Z.tf and .p.tf . In the above example, it will give tf_wilcox.p.tf and tf_wilcox_Z.tf .
    2. All TF files should be compatible (in terms of number of channels and samples, number of pre-stimulus samples, sampling frequency, number of frequencies) to the first TF file (file 1 in condition 1).


  • Current version
  • 1.06 17-07-2012

  • History
    • 1.00 01-08-2001 (OB/CTB/PEA) : 1st documented version.
    • 1.01 16-03-2011 (PEA) : updates to use cmake and free release of Elan. Adds the difference between 2 conditions. Adds .p.tf creation.
    • 1.02 24-03-2011 (PEA) : fixes an error in name reading (from 1.01).
    • 1.03 06-04-2011 (PEA) : adds +fdr option to compute FDR.
    • 1.04 15-04-2011 (PEA) : changes Shell sort to Heap sort in FDR (faster algorithm).
    • 1.05 07-10-2011 (PEA) : adds test for at least 2 samples to test in Wilcoxon test.
    • 1.06 17-07-2012 (PEA) : fixes an error in wilcox function of libstat when all samples are ties.


  • Files
  • $ELANPATH/bin/tfavgwilcox

  • See also