Estimate time delay (dead time) from data
nk = delayest(Data)
nk = delayest(Data,na,nb,nkmin,nkmax,maxtest)
nk = delayest(___,Name,Value)
nk = delayest(Data) estimates time delay from the single-output data
data can be in the form of a
timetable, a comma-separated pair of numeric matrices, or an
iddata object. It can also be an
idfrd object defining
data is a timetable, the software assumes that the last
variable is the single output. If the timetable contains more variables than you want to
use, or the single output channel is not the last timetable variable, select specific
input and output channels for the delay estimation by specifying the
data is in the form of a numeric matrix pair
u,y, then u must be an
Ns-by-Nu matrix and y must
be an Ns-length column vector. Here, Ns is the
number of samples and Nu is the number of inputs. Since
u,y contains no sample time information, also
specify the name-value arguments
nk is returned as an integer or a row vector of integers, containing
the estimated time delay in samples from the input(s) to the output in
The estimate is based on a comparison of ARX models with different delays:
nk = delayest(Data,na,nb,nkmin,nkmax,maxtest) specifies
additional options. The integer
na is the order
of the A polynomial (default 2).
nb is a row vector
of length equal to the number of inputs, containing the order(s) of
the B polynomial(s) (default all 2).
row vectors of the same length as the number of inputs, containing
the smallest and largest delays to be tested. Defaults are
nkmin = 0 and
nkmax = nkmin+20.
entered as scalars in the multiple-input case, all inputs will be
assigned the same values.
maxtest is the largest
number of tests allowed (default 10,000).
nk = delayest(___,
uses additional model options specified by one or more name-value arguments.
The available arguments consist of
OutputName, which are the input and output channel names. Use
these arguments especially when
data is a timetable that has more
variables than you want to use. Also use
OutputName to identify the
output channels when the timetable
data contains more than one
output variable. Otherwise, the software interprets only the last variable as an output
For example, specify the input and output signal variable names using
Version HistoryIntroduced before R2006a
R2022b: Time-domain estimation data is accepted in the form of timetables and matrices
Most estimation, validation, analysis, and utility functions now accept time-domain
input/output data in the form of a single timetable that contains both input and output data
or a pair of matrices that contain the input and output data separately. These functions
continue to accept
iddata objects as a data source as well, for
both time-domain and frequency-domain data.