Variance of timeseries data
ts_var = var(ts)
ts_var = var(ts,Name,Value)
The timeseries object for which you want the variance of the data.
Specify optional comma-separated pairs of Name,Value arguments. Name is the argument name and Value is the corresponding value. Name must appear inside single quotes (' '). You can specify several name and value pair arguments in any order as Name1,Value1,...,NameN,ValueN.
A string specifying one of two possible values, remove or interpolate, indicating how to treat missing data during the calculation.
A vector of integers, indicating which quality codes represent missing samples (for vector data) or missing observations (for data arrays with two or more dimensions).
A string specifying one of two possible values, none or time.
The variance of ts.data, as follows:
When ts.Data is an N-dimensional array, var always operates along the first nonsingleton dimension of ts.Data.
The following example calculates the variance values of a multivariate timeseries object. MATLAB® calculates the variance independently for each data column in the timeseries object.
Load a 24-by-3 data array. Then create a timeseries object with 24 time values.
load count.dat count_ts = timeseries(count,[1:24],'Name','CountPerSecond');
Calculate the variance of each data column.
1.0e+03 * 0.6437 1.7144 4.6278
MATLAB determines weighting by:
Attaching a weighting to each time value, depending on its order, as follows:
First time point — The duration of the first time interval (t(2) - t(1)).
Time point that is neither the first nor last time point — The duration between the midpoint of the previous time interval to the midpoint of the subsequent time interval ((t(k + 1) - t(k))/2 + (t(k) - t(k - 1))/2).
Last time point — The duration of the last time interval ((t(end) - t(end - 1)).
Normalizing the weighting for each time by dividing each weighting by the mean of all weightings.
Multiplying the data for each time by its normalized weighting.