esort (Control System Toolbox)

Sort continuous-time poles by real part

Syntax

s = esort(p)
[s,ndx] = esort(p)

Description

esort sorts the continuous-time poles contained in the vector p by real part. Unstable eigenvalues appear first and the remaining poles are ordered by decreasing real parts.

When called with one left-hand argument, s = esort(p) returns the sorted eigenvalues in s.

[s,ndx] = esort(p)

returns the additional argument ndx, a vector containing the indices used in the sort.

Example

Sort the following continuous eigenvalues.

p
p =
  -0.2410+ 0.5573i
  -0.2410- 0.5573i
   0.1503         
  -0.0972         
  -0.2590 

esort(p)

ans =
   0.1503         
  -0.0972         
  -0.2410+ 0.5573i
  -0.2410- 0.5573i
  -0.2590

Limitations

The eigenvalues in the vector p must appear in complex conjugate pairs.