Closed ufechner7 closed 1 year ago
I also felt I needed more explanation while reading the original description. But I am still not quite sure if the originally used and now re-used expression "time is in the ... dimension" is the best we can have here. And similarly in the proposed PR I find the statement that "columns represent different points in time" similarly confusingly hinting that there is some information about the times stored in the data. Maybe it is just a language issue (I am not a native English speaker), feel free to ignore my comments and the following suggestion.
How about something like this?
If the time series are multivariate, the variables evolve in time along the last dimension of the array. For a matrix, which is a 2D array, this means that each column represent a value of the (vector) variable at a single time.
Note that I also dared to remove the hyphen from the 'time-series". I would only use it when trying to form an adjective like in "closed-loop stability" vs "stability of the closed loop".
I added the clarification
the sizes of the arrays are
(num_variables, num_timepoints)
(see examples below).
Which together with the already existing examples
julia> d = iddata(randn(2, 10), randn(3, 10), 0.1)
InputOutput data of length 10 with 2 outputs and 3 inputs
should be unambiguous
Explain the meaning of "time is in the last dimension."