pvinfo

Describe parameter vector specified with pvec

Syntax

[typ,k,nv] = pvinfo(pv)
[pmin,pmax,dpmin,dpmax] = pvinfo(pv,'par',j)
vj = pvinfo(pv,'par',j)
p = pvinfo(pv,'eval',c)

Description

pvinfo retrieves information about a vector p = (p₁, . . ., p_n) of real parameters declared with pvec and stored in pv. The command pvinfo(pv) displays the type of parameter vector ('box' or 'pol'), the number n of scalar parameters, and for the type 'pol', the number of vertices used to specify the parameter range.

For the type 'box':

[pmin,pmax,dpmin,dpmax] = pvinfo(pv,'par',j)

returns the bounds on the value and rate of variations of the j-th real parameter p_j. Specifically,

$$p\min \le p_j(t)\le p\max ,dp\min \le \frac{d{p}_j}{dt}\le dp\max$$

For the type 'pol':

pvinfo(pv,'par',j)

returns the j-th vertex of the polytope of Rⁿ in which p ranges, while

pvinfo(pv,'eval',c)

returns the value of the parameter vector p given its barycentric coordinates c with respect to the polytope vertices (V₁, . . .,V_k). The vector c must be of length k and have nonnegative entries. The corresponding value of p is then given by

$$p=\frac{{\displaystyle \sum _{i=1}^k{c}_i{V}_i}}{{\displaystyle \sum _{i=1}^k{c}_i}}$$

Version History

Introduced before R2006a