3.2. DATAOBJECTS 77
# index of the pdm the value 100.
idxlst = indexlist([4,1,2])
pdm1(idxlst) = 100
Operations on the Independent Variables/Domain
The domain of a pdm is readily changed via the pdm command. The followingexample
illustrates a common application; changing a frequency domain in Hertz to
radians/second.
# The following scales the domain of a pdm,
# pdm1, by a factor of 2*pi
newpdm = pdm(pdm1,2*pi*domain(pdm1))
Xmath provides a general purpose check which can be used to check whether twopdm s
have the same domain. For more information on this function, refer to Section 3.3.1.
The following example illustrates this application.
# Check whether or not pdm1 & pdm2 have the
# same domains.
stat = check(pdm1,pdm2,{samedomain})
# stat = 1 if the domains are the same
3.2.3 Subblocks: selecting input & outputs
Because the Dynamic System is an Xmath data object, standard matrix referencing
can be used to select subsets of the inputs and outputs. This is illustrated in the
following.
# Select inputs 1, 3,4&5andoutputs 2 & 7 from the
# system: bigsys.
subsys = bigsys([1,3:5],[2,7])
The same format has exactly the same functionfor pdms.