Programmer Guide/SPU Reference/AVR

Average input X over evaluation cycles.

[SPU SUM X TYP T RS OUT Y]

In:	X	a number, vector or matrix containing the data to be averaged
	TYP	a number or string; defines the averaging method
	T	averaging parameter (number); depends on method
	RS	reset flag (number)
Out:	Y	averaged input X; same type as X

Description

The averaging algorithm is defined by the inputs TYP and T. The atom averages the elements X[i,j]_t over evaluation cycles t (i=row index, j=column index, t=cycle counter) and stores the averaged value in the element Y[i,j]_t.

The cycle counter t is initialized with 0 and incremented by 1 after each evaluation cycle. The cycle counter is reset, if the input RS is set to a value greater than 0. The input RS is checked each time the SPU is started.

infinite average

TYP=0 or linear

T=0

Y[i,j]t={X[i,j]tif t=01t+1(t.Y[i,j]t−1+X[i,j]t)if t>0

running average

TYP=0 or linear

T>0; T is the (integer) number of averaging cycles

Y[i,j]t={1t+1∑z=0tX[i,j]zif 0⩽t<T1T∑z=0T−1X[i,j]t−zif t⩾T

exponential average

TYP=0 or linear

0<T<1; T is the averaging factor

Y[i,j]t={X[i,j]tif t=0 (or T out of range)1T∑z=0T−1X[i,j]t−zif t>0

See also

<SP-atoms>