pvec

Syntax

pv = pvec('box',range,rates)
pv = pvec('pol',vertices)

Description

pvec is used in conjunction with psys to specify parameter-dependent systems. Such systems are parametrized by a vector p = (p₁, . . ., p_n) of uncertain or time-varying real parameters p_i. The function pvec defines the range of values and the rates of variation of these parameters.

The type 'box' corresponds to independent parameters ranging in intervals

The parameter vector p then takes values in a hyperrectangle of Rⁿ called the parameter box. The second argument range is an n-by-2 matrix that stacks up the extremal values $${\underset{¯}{p}}_j$$ and $${\overline{p}}_j$$ of each p_j. If the third argument rates is omitted, all parameters are assumed time-invariant. Otherwise, rates is also an n-by-2 matrix and its j-th row specifies lower and upper bounds $${\underset{¯}{\nu }}_j$$ and $${\overline{\nu }}_j$$ on $$\frac{d{p}_j}{dt}$$:

Set $${\underset{¯}{\nu }}_j$$ = –Inf and $${\overline{\nu }}_j$$ = Inf if p_j(t) can vary arbitrarily fast or discontinuously.

The type 'pol' corresponds to parameter vectors p ranging in a polytope of the parameter space Rⁿ. This polytope is defined by a set of vertices V₁, . . ., V_n corresponding to “extremal” values of the vector p. Such parameter vectors are declared by the command

pv = pvec('pol',[v1,v2, . . ., vn])

where the second argument is the concatenation of the vectors v1,...,vn.

The output argument pv is a structured matrix storing the parameter vector description. Use pvinfo to read the contents of pv.

Version History

Introduced before R2006a

See Also

pvinfo | psys