How to input .MAT File to Embedded Matlab Function in Simulink
in [Matlab]
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From: Jimmy on 14 Apr 2010 10:39 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
From: Guy Rouleau on 14 Apr 2010 18:20 "Jimmy " <royalflush_cc(a)yahoo.com> wrote in message <hq4k28$g34$1(a)fred.mathworks.com>... > Hi, > > I would like to input .MAT file to Embedded Matlab Function in Simulink. > The.MAT file contains 2 rows. Row 1 is time and row 2 is amplitude value. > Would you please advise how I can do this? I cannot get it to work. > > thank you I depends on what is your goal: - For simulation purpose only and if you want all the data in the MAT-file at the beginning of the simulation, you can declare LOAD as extrinsic and load the MAT-file in EML. You should include some logic to load it only once and keep the data as persistent. - if you want to use in EML the amplitude (data in column 2) at the time specified in column 1, then you should use a From File block in simulink and connect the input of this block as an input to the EML block as any other signal. I hope this helps. Guy
From: Jimmy on 15 Apr 2010 09:37 Guy, Thanks for your reply. I would like to use the amplitude values (Row 2) at the time specified at row 1. I used the "from file" block and connect it to the EML, but I don't think the EML recognized the matrix from the .mat file. I tried to use the command length(u) and it does not return the correct value. Is it possible that I have to change some settings in EML for the input to recognize matrix or vector input? thanks "Guy Rouleau" <guy.rouleau.nospam(a)mathworks.com> wrote in message <hq5f35$do9$1(a)fred.mathworks.com>... > "Jimmy " <royalflush_cc(a)yahoo.com> wrote in message <hq4k28$g34$1(a)fred.mathworks.com>... > > Hi, > > > > I would like to input .MAT file to Embedded Matlab Function in Simulink. > > The.MAT file contains 2 rows. Row 1 is time and row 2 is amplitude value. > > Would you please advise how I can do this? I cannot get it to work. > > > > thank you > > I depends on what is your goal: > > - For simulation purpose only and if you want all the data in the MAT-file at the beginning of the simulation, you can declare LOAD as extrinsic and load the MAT-file in EML. You should include some logic to load it only once and keep the data as persistent. > > - if you want to use in EML the amplitude (data in column 2) at the time specified in column 1, then you should use a From File block in simulink and connect the input of this block as an input to the EML block as any other signal. > > I hope this helps. > > Guy
From: Guy Rouleau on 15 Apr 2010 10:05 You have a matrix of 2 columns. Each element of column 2 correspond to a time value in column 1. In this case, the From File block will not output a matrix. At each time step, it will output a scalar value (the amplitude value corresponding to the time specified in colum 1) and this is what the EML block will receive. The EML block will then receive a new scalar every time step. So doing length(u) in EML should return 1. I am not sure I understand why you expect the EML block to receive a matrix or vector because you say "I would like to use the amplitude values (Row 2) at the time specified at row 1" Am I missing something? Guy "Jimmy " <royalflush_cc(a)yahoo.com> wrote in message <hq74q0$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
From: Jimmy on 15 Apr 2010 14:11
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 |