How to input .MAT File to Embedded Matlab Function in Simulink
in [Matlab]
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From: Guy Rouleau on 15 Apr 2010 14:27 Hi, Using the From File block to input your signal into Simulink is a good start. After that, it depends on how you prefer to work. Peoples who prefer to write MATLAB code will use EML, peoples (like me) who prefer block diagrams will implement the algorithm using Simulink blocks. Both ways are good. About the FFT algorithm, I implemented that as a homeworks years ago, but since then I always use the FFT block shipped for the Signal Processing blockset, so I can't really help with that! Have fun with your homework ;-) Guy "Jimmy " <royalflush_cc(a)yahoo.com> wrote in message <hq7krp$lgs$1(a)fred.mathworks.com>... > Guy, > > You are absolutely correct. Length (u) returns a value of 1. I thought before that "from file" block outputs a matrix, but you have convinced me that it does not work that way. > > I probably did not explain what I wanted to do very well. Basically, the ultimate goal is to create a simulink block that takes sample input signal and outputs the magnitude and phase of the signal (much like Discrete Fourier Filter block on SimpowerSystem). However, I am not allowed to use the discrete fourier filter block (since this is a school assignment and the prof. does not allow us use that block). Instead, I need to write my own code in simulink. > > To accomplish this, I think the first step is to get the amplitude values of the signal at every sampling instance. So lets say the sampling time is 1/1000, I will need to get the amplitude values of the signal at time 0, 1/1000, 2/1000, 3/1000, and so on until the signal ends. > > There is no requirement to use EML or even to use .MAT file. It was just my idea. > I would appreciate if you have any suggestion. > > Thanks again for replying my question. > > > > "Guy Rouleau" <guy.rouleau.nospam(a)mathworks.com> wrote in message <hq76ev$g3p$1(a)fred.mathworks.com>... > > You have a matrix of 2 columns. Each element of column 2 correspond to a time value in column 1. > > > > In this case, the From File block will not output a matrix. At each time step, it will output a scalar value (the amplitude value corresponding to the time specified in colum 1) and this is what the EML block will receive. The EML block will then receive a new scalar every time step. > > > > So doing length(u) in EML should return 1. > > > > I am not sure I understand why you expect the EML block to receive a matrix or vector because you say "I would like to use the amplitude values (Row 2) at the time specified at row 1" > > > > Am I missing something? > > > > Guy > > > > "Jimmy " <royalflush_cc(a)yahoo.com> wrote in message <hq74q0$g4b$1(a)fred.mathworks.com>... > > > Guy, > > > Thanks for your reply. > > > I would like to use the amplitude values (Row 2) at the time specified at row 1. > > > I used the "from file" block and connect it to the EML, but I don't think the EML recognized the matrix from the .mat file. I tried to use the command length(u) and it does not return the correct value. Is it possible that I have to change some settings in EML for the input to recognize matrix or vector input? > > > > > > thanks > > > > > > > > > "Guy Rouleau" <guy.rouleau.nospam(a)mathworks.com> wrote in message <hq5f35$do9$1(a)fred.mathworks.com>... > > > > "Jimmy " <royalflush_cc(a)yahoo.com> wrote in message <hq4k28$g34$1(a)fred.mathworks.com>... > > > > > Hi, > > > > > > > > > > I would like to input .MAT file to Embedded Matlab Function in Simulink. > > > > > The.MAT file contains 2 rows. Row 1 is time and row 2 is amplitude value. > > > > > Would you please advise how I can do this? I cannot get it to work. > > > > > > > > > > thank you > > > > > > > > I depends on what is your goal: > > > > > > > > - For simulation purpose only and if you want all the data in the MAT-file at the beginning of the simulation, you can declare LOAD as extrinsic and load the MAT-file in EML. You should include some logic to load it only once and keep the data as persistent. > > > > > > > > - if you want to use in EML the amplitude (data in column 2) at the time specified in column 1, then you should use a From File block in simulink and connect the input of this block as an input to the EML block as any other signal. > > > > > > > > I hope this helps. > > > > > > > > Guy |