Load initial state in multirate systems

Hallo,

ttbomk, Simulink does not offer a way to piecewise process large data sets that won't fit into the workspace. A workaround is to run simulink with a piece of the data, save last state of the model, start simulink with next piece of data and the final state from the last run as the initial state, as is proposed here: http://www.mathworks.it/matlabcentral/newsreader/view_thread/260837. I can make this work for single-rate models, but it fails for multirate systems. In my evaluation I found that the state of the 'OutBuff' of a multirate filter and thus the filter's output is different when processing the data piecewise compared to processing the data in one piece.

Any idea why this is the case?

Thanks for your help.

Answer 1

[Kaustubha Govind]

Which block is that exactly? If it a block from the Simulink library, it is worth reporting this to MathWorks Tech Support so that SimState support for that block is fixed.

Also, I believe the "From File" block reads data one sample at a time - so this might potentially be a solution to the problem of not being able to fit your input data in the workspace. (The other suggestions on the newsgroup thread are also excellent)

[Philipp]

>Which block is that exactly?

I tested with a 2x FIR halfband decimation filter block generated by fdatool.

[Kaustubha Govind]

Phillip: Is that block implemented in terms of basic Simulink blocks? Which is the block that corresponds to the state OutBuff?