I want to import one matrix 5x5 from Workspace to Simulink. The software gives me an error: "Invalid workspace variable specified as workspace input in 'MODELLO_From Workspace'. Time values must be non-decreasing." How can I solve the problem?
You can use constant block for that.
Here First I created a variable as sample_matris (5x5) in workspace.
sample_matris = rand(5,5);
Here is the values created in workspace.
Then I used constant and entered name of the variable defined in workspace.
You can see that I can use values defined in workspace, by using constant block in simulink. If you need specific indices of the matris, you can use selector block in Simulink.
Related
I am running my test.m file to create variables in my base work space. This is the content of my test.m file :--
a=10; % define a variable with particular value
b=20; % define a variable with particular value
c=0; % define a variable with particular value
In my MATLAB model now i am trying to access the variables a & b. But it is returning me the value zero for both a & b.
I am using a function call generator to trigger a model every 10 msec.
Solver type : Fixed Step
Solver : Discreate(No Continous states)
Why i am not able to access the workspace variables in my simulink model.
Please see the attached print shot.
You are using an Inport and you named it with the variable name but it does not affect the variable to it, it is only a port. Try using the Constant block and set it to your variable name ("a" for example)
I am using Matlab function in my simulink code where I am using the load command for getting some matrices and variables from the workspace
persistent ProblemParams;
if isempty(ProblemParams)
ProblemParams = load('ProblemParams.mat');
end
This is working well, however there can be problem when I am running multiple simulations at the same time, hence I would like to know what other options do I have to pass an array to this block from MATLAB workspace?
Whether or not the above works, it's not the right way to get data into the block. You should load the variable into the MATLAB Workspace prior to starting the simulation, then pass the variable into the MATLAB Function Block as a Parameter Argument.
I would like to export one scalar variable from a Simulink Diagram to the Matlab Workspace.
Although I know that the value of 'Chemin' can be changed during the simulation, I am only interested in exporting the initial value to the workspace; I do not want a TimeSerie variable (like the 'To Workspace' block would do), I only one want scalar value.
Thank you in advance for your help!
I don't think you can do what you want. Everything in Simulink is time-based so you have to save the entire variable as a function of time to the workspace. However, you can add a model callback in StopFcn that extracts just the first value and clears the time-dependent variable from the workspace, e.g.:
chemin_0 = chemin(1); % assuming chemin is the name of the time-dependent variable saved to workspace
clear chemin
The StopFcn callback is executed after the simulation stops.
You can do this pretty easily with an Enabled Subsystem. Make the enable signal false at all times except t=0 by using a constant (=0) and an Initial Condition block (=1), as per the following picture.
Inside the Enabled Subsystem have
with the save format set to be Array. The simout variable will then be a scalar valued number.
I need to read a matrix variable from the workspace in Simulink. I am using the simin block but I have a problem with this. It shows me the following error:
Invalid workspace variable specified as workspace input in
'untitled1/From Workspace'. Time values must be monotonically
increasing.
Which properties of this block (simin) or the matrix variable in workspace should I change to read it in simulink with the block correctly and operate with it (Multiply, Transpose....)?
what does your input variable look like? I use a structure:
variable1.time=[0 1 2];
variable1.signals.values=rand(1,3);
I've been doing a lot of research over the last few hours and I can't seem to figure out how to get and set a value to an Inport box. I have a simple model that has one inport and one outport and they are connected to each other. I want to set the inport value to 2 and run my simulation and see if my outport got set correctly. I read that you can't use set_param to set that value but you have to use sim(), but I'm not having any luck with that. So if anyone know how to look at the data in the inport box and/or how to set it, I'd appreciate it. Thanks!
Lucas
Ports in and out in Simulink don't work as you think. They are needed when you create subsystem - your own Simulink block, than you'll have your in and out ports.
But when you just want a make some model, and pass some data in it, and get results to Matlab, then you need To workspace and From workspace blocks. Some variable-name is assigned in their options, so you can set input data from your .m file and get results in matlab variables.
Block From workspace takes matrix variable, but if you want to pass just a number, you can use block Const and fill it value with a variable name.
Here is a screenshot, an example of in, out, to workspace and const blocks:
Here in example, I have input parameter x (block const), subsystem Gain5 and output parameter y (block To workspace). Inside the subsystem I use in and out blocks to get and return values.