﻿ Descriptive statistics
 Descriptive statistics

•    BASIC STATS          A; 'b'  Computes the mean, range, standard deviation (SD), standard error (SE), and coefficient of variation (CV) of the block (it also shows the time duration and the data range).   For convenience, this can be accessed from the keyboard by typing the ‘b’ character.

To get the integrated total for a rate function, such as oxygen consumption, make sure the correct rate unit is selected (i.e., 'per min' if the units are ml/min or 'per hour' if the units are ml/hour).  A more sophisticated integration mode is available in the INTEGRATE BLOCK option.

If the open file has more than one channel, you can switch channels by clicking on the small numbered channel selection buttons.   You can see the channel labels if you 'float' the cursor over these buttons.

Use the 'limits' buttons to restrict analysis to a subsection of the block.  Click the right or left limit button, then use the cursor to select the limits in the block window.

The 'scale' button toggles scaling of the results (see SCALE RESULTS, below).  The 'Store' button in this and other analysis mode windows allows you to directly transfer the current mean for use as a scaling factor.  When you click 'Store', the scaling factors window appears.  Click on any channel's "*" or "÷" button, and the current mean will appear in the first edit field (the multiplication or division factor) for that channel.

The 'select,' '≥' and '≤' buttons at the bottom of the window let you get basic statistics for a subset of the block, within the defined numeric limits.   Note that there must be at least 3 data points within the subset limits, or the program will issue a warning buzz, turn off the '≥' and '≤' buttons, and default to the previous basic statistics results.

If you restrict analysis to a subset of data, or use cross-channel subsets, a warning window will appear for analyses that 'pay attention' to subset settings.   This example shows cross-channel selection is being used, and within the channel being analyzed, data with values less than 0.5 or greater than 21.12 are ignored.

The 'distribution' button produces a small histogram (bar graph) of frequency distribution in a small moveable window. You can use the '(big)' button to produce a much larger and more detailed histogram, with control over the number of bins and bin width (see below). If the file has more than one channel, you can click on buttons for different channels and get those means (you can also use the keyboard to select channels). With an option in the PREFERENCES menu, you can have different histogram windows for each channel, or use the same small window for all channels.

 go to: