User guide

Charnwood Dynamics Ltd. Coda cx1 User Guide – Reference IV-3
CX1 USER GUIDE - COMPLETE.doc 26/04/04 146/162
TEXT DATA FILE (TXT) FORMAT
Summary
Text data files contain a set of movement data coordinates in a tabulated text format. This
format is used to import data into Codamotion Analysis from other applications, or to export
data from Codamotion Analysis to other applications (such as a spreadsheet or a word-
processor). File names usually have the extension TXT, but any extension may be used.
Saving data in Text format
In the File: Save As... dialogue, select the Text (TXT) file type in the ‘Save File as Type:’
selection box. The file name extension defaults to ‘txt’, but this may be changed if desired. If
the data was not loaded from a text file, Codamotion Analysis will ask you to confirm the
change of format. If data filtering in on (Setup: Data Filters...), a further warning dialogue will
appear.
Text data files store marker position data and analogue channel data (Force and EMG, if
any) as tabulated text which can be read by any application program which accepts ASCII
text. The data includes file identification information and data-column headers. Data is tab-
delimited and may be loaded directly into a Microsoft Excel spreadsheet, for example.
Data is stored in lines and columns as follows. (Lines are terminated with a carriage-return
line-feed pair; columns are separated by single Tab characters.)
Line 1: identifies the file as a CODA Text file (“CODAmotion Analysis Text”).
Line 2: stores the original file name and date, and the name of the Setup file which was
loaded at the time the file was saved as text (if any).
Line 3: labels the starting column for each data type (“Time”, “Markers”, (“ForcePlate”),
(“EMG”)).
Line 4: labels each data column with the name used for that data channel in the Motion
Analysis Setup, including a dimension letter for marker data (e.g. “Marker 1.X”,
“Marker 1.Y” etc.).
Line 5: lists the units of each data column (“(s)”, “(mm)”, “(N)”).
Lines 6...end: record the data in floating-point format:
Column 1: epoch time value (seconds)
Columns 2...: marker data in multiples of three columns of x, y, and z coordinate**
values for each marker (in millimetres);
Columns (3m+2)... force-plate data in multiples of eight columns for each plate (in
Newtons).
Columns ()... Analogue EMG data in multiples of eight columns.
Data is stored at the time resolution of acquisition (i.e. every 0.005s for 200Hz data).
If the graphs have been zoomed in when the data is saved in text format (Cursors: Zoom
Graphs to Cursors), then only the zoomed-in data is stored. This can be used to save data
selectively and to reduce the size of the data file.
If data filtering and/or interpolation is on (Setup: Data filters...), then the filtered and/or
interpolated marker data is stored. If you wish to save the un-smoothed/un-interpolated data
in a text format file, you must switch off filtering first.