Systems Theory and Automatic Control

ADMITvariable
ADMIT documentation: ADMITvariable

ADMITvariable

ADMITvariable creates a ADMITvariable object

VAR = ADMITvariable(STR)
VAR = ADMITvariable(STR,varargin)

Parses the string STR and generates a ADMITvariable object from it.
Syntax description is also found in "./examples/OPTFILE_TEMPLATE.opt".

If additional arguments are provided, then this is equivalent to 
CON = ADMITvariable(sprintf(STR,varargin))

In principle you can provide any string satisfying the syntax.

Syntax

General syntax is:
 NAME {TYPE:TIMEDEP} or {TYPE:TIMEDEP:OFINTEREST}

Notes

 - default options for all non-specified variables {real:timeInvariant}
 - possible settings for TYPE : real | integer | binary
 - possible settings for TIMEDEPendency : timeInvariant | timeVariant
 - possible settings for OFINTEREST : ofInterest or ofInterest(TIME)
   if TIME is provided, then the variable is 'of interest' for all  
   time-points of the specified set; syntax for TIME see below. 
 - capitalization of options/settings doesn't matter
 - variables don't have to be specified explicitly in this section; all
   variables found in the constraints are automatically added to the 
   opttask-object; the type and time-variance properties are 
   automatically detected

Examples

The following examples show how to define variables. You can use any
one of the strings below and pass it to ADMITconstraint, e.g.
 ADMITvariable('A {real:timeVariant}')

Add a variable to an ADMITproject by using the "+"-operator

 opt = ADMITproject();
 opt = opt + ADMITvariable('A {real:timeVariant}')

Remove a variable from an ADMITproject by using the "-"-operator

 opt = ADMITproject();
 opt = opt + ADMITvariable('A')
Note: In this case, the variable 'A' is removed from the ADMITproject by
replace each occurrence of 'A' by its definition (IF IT CAN BE DETERMINED):
 opt = opt + ADMITconstraint('A := [1]')
 opt = opt + ADMITconstraint('A*B > 1')
 opt = opt - ADMITvariable('A')
In the previous example A is replace by constant value 1; the value for a
is determined from the "constant" bounds.

or:
 opt = ADMITproject();
 opt = opt + ADMITvariable('A')
 opt = opt + ADMITconstraint('A := A = 2')
 opt = opt + ADMITconstraint('A*B > 1')
 opt = opt - ADMITvariable('A')
In the previous example A is replace by constant value 2; the value of
the A is determined by looking for the constraint named 'A' and by
solving for A.

Setting type of an variable

 opt = ADMITproject();
default type for variables is 'real'
 opt = opt + ADMITvariable('A')
 opt = opt + ADMITvariable('A {binary}')
 opt = opt + ADMITvariable('A {integer}')
Note that you cannot change the time-variance property of a variable once
it has been added!

Setting a variable to be "of-interest"

 opt = ADMITproject();
 opt = opt + ADMITtime('t_sim := {0:10}');
 opt = opt + ADMITconstraint('C(t_sim) := C(t) = C(t-1) - lambda*C(t-1)');
 opt = opt + ADMITconstraint('C(*) := [0,1]');
 opt = opt + ADMITconstraint('C(1) := [0.5,0.6]')

If you want to do parameter estimation, you can set time-invariant
variables to be "of-interest" as follows:
 opt = opt + ADMITvariable('lambda {ofInterest}')

To estimate the initial conditions of C, you can do the following:
 opt = opt + ADMITtime('t_0 := 0')
 opt = opt + ADMITvariable('C {timeVariant:ofInterest(t_0)}');
Note that you have to define "t_0" and that you must not change the
time-variance property of "C".

To do state-estimate for C, you can do the following:
 opt = opt + ADMITvariable('C {ofInterest(*)}');

Then by calling ADMITestimate(...), consistent bounds for the 
variables of interest are determined.

Defining variables and their properties

 A {real:timeVariant}
 B {real:timeVariant}
 C {binary:timeInvariant:ofInterest}
 D {integer:timeVariant:ofInterest(t_0)}
 E {real:timeVariant}