[Master Index] [Index for /tools/hpmatlab/toolbox/signal]

zp2sos

(/tools/hpmatlab/toolbox/signal/zp2sos.m)

Function Synopsis

sos = zp2sos(z,p,k,direction_flag)

Help text

ZP2SOS	Zero-pole-gain to second-order sections linear system model conversion.
	SOS = ZP2SOS(Z,P,K) finds a matrix SOS in second-order sections form
	which represents the same system as the one with zeros in vector Z, 
	poles in vector P and gain in scalar K.  The poles and zeros must 
	be in complex conjugate pairs.

	ZP2SOS(Z,P,K,'down') orders the sections so that the first row of SOS 
	contains the poles closest to the unit circle. Without the 'down' flag,
	the sections are ordered in the other direction.

	The output SOS is an L by 6 matrix which contains the coefficients 
	of each second-order section in its rows:
	    SOS = [ b01 b11 b21  a01 a11 a21 
	            b02 b12 b22  a02 a12 a22
	            ...
	            b0L b1L b2L  a0L a1L a2L ]
	The pole-zero conjugate pairs which are closest to each other are 
	arranged into the same 2nd-order section.  Furthermore, the numerator
	coefficients of each section are scaled so that the maximum of the
	magnitude of the DTFT of the cascade is very close to 1.

	The system transfer function is the product of the second-order transfer
	functions of the sections.  Each row of the SOS matrix describes
	a 2nd order transfer function as
	        b0k +  b1k z^-1 +  b2k  z^-2
	        ----------------------------
	        a0k +  a1k z^-1 +  a2k  z^-2
	where k is the row index. 

	See also SOS2ZP, SOS2TF, SOS2SS, SS2SOS, CPLXPAIR.

Cross-Reference Information

This function calls
This function is called by
Produced by mat2html on Wed Feb 8 12:25:18 EST 1995
Cross-Directory links are: ON