Code covered by the BSD License

# Dynamical Systems Toolbox

13 Jul 2011

Bifurcation analysis of dynamical systems. Integration of AUTO bifurcation software into MATLAB.

pvls(ndim,u,par)
```      function []= pvls(ndim,u,par)
%
%
%
%
% note :
% parameters set in this subroutine should be considered as ``solution
% measures'' and be used for output purposes only.
%
% they should never be used as `true'' continuation parameters.
%
% they may, however, be added as ``over specified parameters'' in the
% parameter list associated with the auto constant nicp, in order to
% print their values on the screen and in the ``p.xxx file.
%
% they may also appear in the list associated with auto constant nuzr.
%
%
% for algebraic problems the argument u is, as usual, the state vector.
% for differential equations the argument u represents the approximate
% solution on the entire interval [0,1]. in this case its values must
% be accessed indirectly by calls to getp, as illustrated below.
%
%
% set par(2) equal to the l2 norm of u(1)
par(2)=getp('nrm',1,u);
%
% set par(3) equal to the minimum of u(2)
par(3)=getp('min',2,u);
%
% set par(4) equal to the value of u(2) at the left boundary.
par(4)=getp('bv0',2,u);
%
%
% the first argument of getp may be one of the following:
%        'nrm' (l2 norm),     'max' (maximum),
%        'int' (integral),    'bv0 (left boundary value),
%        'min' (minimum),     'bv1' (right boundary value).
%
% also available are
%   'stp' (pseudo arclength step size used).
%   'fld' (`fold function', which vanishes at folds).
%   'bif' (`bifurcation function', which vanishes at singular points).
%   'hbf' (`hopf function'; which vanishes at hopf points).
%   'spb' ( function which vanishes at secondary periodic bifurcations).
%
%
return
```