User guide

Charnwood Dynamics Ltd. Coda cx1 User Guide – Coda Basics I - 2
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To check the effect of filtering, use the Filtering On/Off control.
When filtering is on, it is applied to the graphs of all currently open data files; it is not
possible to plot both filtered and unfiltered data simultaneously. The filters affect only the
data plotted on the graphs: the data stored in the data file is not affected, even if it is re-
saved. Force and EMG data is not filtered.
The filters are simple running-average (square) filters, so may show some aliasing effects
if the data has strong components at certain frequencies. Also, the filtering will only have
an effect when the filter frequency is below half the sampling rate: the data is filtered by
averaging over a progressively larger number of samples as the filter frequency is
reduced.
Comments View
Comments view allows you to enter text which can contain any interesting or important
information about a data file. Comments are saved when you save the data file. You can
edit comments after they have been entered, by cutting or copying them to the windows
clipboard. This also allows you to paste comments into other Windows applications, such
as word processors.
Entering comments
Choose View Comments from the Views menu.
Click with the mouse where you wish to enter text.
Type the text in using the keyboard.
Editing comments
Once you have entered your comments, you can change them using the standard
keyboard delete and backspace keys. You can edit comments in exactly the same way as
in the Windows Notepad application, using the Edit menu Cut, Copy, and Paste
commands.
One particularly useful detail you might wish to enter in the datafile Comments is the
filename of a default Setup which will facilitate automatic loading of the Setup on the next
occasion the datafile is loaded:
Variables
In this context, variables are parameters of motion patterns such as gait which can be
defined from values on graphs. You can gather a set of variables for several data files,
and they can be exported to a spreadsheet/database where you can build up a set of
statistics about the motion of subjects.
For a particular study, you will always want to collect the same set of variables from all the
data files which you gather. To ensure that the same set of variables is always collected,
the types of variables which you are collecting can be stored as part of the setup which
you are using for the study. This means that you create the variable types at the time
when you create graphs, the stick figure joining diagram, and other setup attributes.