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h_strike

(beat/h_strike.m)


Function Synopsis

events = h_strike (data, dataType, numstds, side)

Help text

H_STRIKE  Pick heel strike (contact) events from data.

   H_STRIKE finds the heel strike events in a set of gait data.

   EVENTS = H_STRIKE (DATA, DATATYPE, NUMSTDS SIDE) 
   finds the heel strike events in the data given by DATA, which is 
   of type DATATYPE.  

   DATATYPE is a string which is either 'motion', 'switch', or 'force'.  

   When DATATYPE is 'motion', DATA is assumed to be a vector containing
   motion data, in which we'll look for minima.  When DATATYPE is 'switch',
   DATA is assumed to be a vector of footswitch data (similarly, for
   'force', force plate data is used, which is processed the same way as
   'switch'), in which we'll look for a sudden increase.  If DATATYPE 
   is not given, it is assumed to be 'motion'.  

   NUMSTDS refers not to sexually transmitted diseases, but to the 
   number of standard deviations used in determining whether a point 
   is a heel strike if the data is specified as either 'switch' or 
   'force'; it defaults to 5.  
   
   SIDE is specified as 'l' or 'r', and tells whether this is data for the right
   or left side for V-Scope data (or for any other data where the coordinate
   system flips from one side to the other.  It defaults to 'l' (which should
   be appropriate for data taken with other systems).

   For 'motion' data, heel strike is assumed to occur when the velocity goes
   from positive to negative (passes through 0, going down) (this is reversed 
   if side is specified as 'r').

Cross-Reference Information

This function calls

Produced by mat2html on Wed Jun 20 12:12:51 2001
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