Stats Tab

Compute statistical measurements on your data waves such as Max, Min, Avg, Slope, Rise Time.

Use NeuroMatic’s Wave Increment Controls (3) to step through your data waves. Results are displayed in the currently selected Channel Graph and on the right of the Stats Tab (y, x).

Use NeuroMatic’s Channel & Wave Select Controls (7) to select the channel (e.g. “A”) and set of waves you wish to analyze (e.g. “All” or “Set1” or “Group0”). Select the Stats All Waves button. Results are saved to Stats Waves which can be displayed in tables and graphs.

Use Stats2 controls to display and analyze your Stats Waves.

Download the Stats Tab Igor experiment demo.

Stats1

Select the type of measurement you wish to compute from the Stats1 top-left drop-down menu. Results are displayed at right (y, x, m, b).

    Off – turn off the Stats window computation.

    Max – maximum (y, x)

    Min – minimum (y, x)

    Avg – average (y)

    Median (y)

    SDev – standard deviation (y)

    Var – variance (y)

    RMS – root mean square (y)

    Area (y)

    Sum (y)

    PathLength – distance between data points (y)

    Slope (m, b, where y = mx + b)

    Onset – find the onset of an “event” by fitting a sigmoid (Boltzmann) function to the data and computing the maximum curvature (Fedchyshyn and Wang, 2007) (y, x)

    Level – first level crossing (x)

    Level+ first level crossing on positive slope (x)

    Level- first level crossing on negative slope (x)

    MaxAvg – average computed in a window centered on the maximum (y)

    MinAvg – average computed in a window centered on the minimum (y)

    RiseTime – compute the rise time from the baseline to a Max or Min point. Default is a 10-90% rise time (x)

    RTslope – rise-time slope. Compute the slope between the first and second rise-time points (m, b)

    DecayTime – compute the decay time from a Max or Min point to the baseline. Default is a 37% decay time, one-exponential time constant (x)

    FWHM – compute the full-width half-max between the baseline and a Max or Min point (x)

xbgn, xend – enter the x-axis measurement begin/end window here, or use your mouse to drag the red vertical Stats Drag Waves displayed in the currently selected Channel Graph.

Baseline (Bsln) – click this checkbox to compute a baseline value (b), with the option to automatically subtract the baseline value from the y-data measurement.

Filter – compute measurements on filtered or smoothed waves by entering the filter frequency in kHz, or the number of smoothing points. Enter “0” for no filtering or smoothing.

Transform – click this checkbox to compute measurements on differentiated, double-differentiated, integrated, normalized waves, etc.

x-offset – click this checkbox to create a wave of x-axis offset (shift) values for each of your data waves or each of your Groups. For example, if you have paired-pulse data in which the interval between pulses is incremented in steps of 10 msec, create a group offset wave by clicking the x-offset checkbox and enter 0, 10, 20, 30... into the group wave that appears in the offset table (here, wave indexes denote the group number). Now step through your data using NeuroMatic’s Wave Increment Controls (3). You should see your Stats1 measurement windows in the Channel Graph shift in steps of 10 msec according to the group number of the currently selected wave.

Win – use the top-right drop-down menu to define new Stats1 measurement windows. Or select Edit All Inputs to edit Stats1 input parameters in a table, or Edit All Outputs to edit Stats1 output measurements in a table. Select More/Less to change the number of available measurement windows.

All Waves – click this button to compute measurements on all currently selected channels and waves (7). Results are saved to Stats Waves which can be displayed in tables and graphs using the Stats2 functions defined below.

Stats2

Folder Select – choose a Stats Subfolder to analyze, or the currently selected NeuroMatic data folder.

Wave Select – choose the wave to analyze. The wave’s statistics will appear on the panel (average, standard deviation and number). Choose Change This List to change the list of waves listed in the drop-down menu. Select “All Stats” to list all Stats1 and Stats2 waves. Select “Any” to list all waves in the selected data folder. Select a window, such as “Win0”, to list only those Stats Waves computed for that window.

Functions – choose a function to perform on the currently selected wave or data folder, such as Plot, Edit, Histogram, etc.

    all – click this checkbox if you want to perform a Stats2 function on all waves listed within the Wave-Select drop-down menu.

    Inequality – perform an inequality test (y > a, y < b, a < y > b) on the y-values of the currently selected wave. For example, one might want to define a y-amplitude > 2 nA as a success, and anything smaller as a failure. The Inequality function will produce an output wave of the same dimension as the input wave, with point value 1 for success or 0 for failure. You will have the option to save these results to a Set which you can then use to limit your data analysis using Neuromatic’s Wave Select Control (7).

    Stability – use this function to compute the stability/stationarity of the currently selected wave, such as a wave of baseline values, or a wave of peak amplitudes. This function was provided by the The Silver Lab at University College London, and was derived from a Spearman Rank-Order macro from Numerical Recipes.

    Significant Difference – This function impliments the Kolmogorov-Smirnov Test for two sets of unbinned unsorted data. The test finds the maximum value of the absolute difference D between two cumulative distributions, and prints a global variable for the absolute difference (ST_KSd), and the probability that D is significant (ST_KSprob). This function was provided by the The Silver Lab at University College London, and was derived from from Numerical Recipes.

    MPFA Stats – compute statistics for multiple-probability fluctuation analysis: mean, variance and error of variance (Saviane and Silver 2006).

Stats Waves

>> Stats Waves are now created inside Subfolders by default.

>> The default length of Stats1 Waves now equals the number of currently selected waves. If you wish the length to equal the number of channel waves, the old default length, click the Configs checkbox on the bottom of the Stats Tab, click WaveLengthFormat and select “waves per channel”.

Stats1 Waves are created with the following name convention: “ST_” + Measurement X/Y + Stats1 Window Number + Wave Select String + Channel + Overwrite Sequence Number (e.g. “ST_MaxY0_RAll_A0”).

Stats2 Waves begin with the prefix “ST2”.