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How can I send a result to the workspace and take the same result from workspace ??

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kamal kiki
kamal kiki on 13 Feb 2012
Edited: Matt J on 13 Oct 2013
My simulink model is containing two parts, and each part is formed by differents blocks. In the first part I am doing complicated calculations and sending the final result to the workspace using the "to workspace" block after giving the name A to the variable.
The second part of my model is containing a MATLAB fcn block (the fsolve function)which is taking its guess from the workspace through the block "from workspace" which is having the name of its variable changed to "guess".
My fsolve function needs the variable A because one of the equations that has to be solved is containing the variable A as parameter.
when I type in the command window the value of A and of the guess and after that I run the simulation of the second part, fsolve is working and the results are displayed on the "display block".
but
when I run the simulation of the first part the signs double are displayed in front of A in the workspace but no value for A is given. After that when I run the simulation of the second part of the model(containing fsolve block), fsolve does not work because it can not access the value of A in the workspace.
Please help me solve this problem.

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Answers (4)

Kaustubha Govind
Kaustubha Govind on 13 Feb 2012
The "To Workspace" block does not write the variable to the workspace immediately, it is only available at the end of the simulation, so the second part of your model cannot access the variable during simulation. Why not connect the signal from the first part directly to the second part?
Btw, also read the second paragraph in my answer on this discussion

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Kaustubha Govind
Kaustubha Govind on 15 Feb 2012
Is the variable "A" created in the base workspace after the first model finishes running? What is the error you get from the second model?
kamal kiki
kamal kiki on 16 Feb 2012
After the simulation of the first model I can see A in the workspace but in front of the value is written : <1x1struct>.
the error messages that I receive are:
Failure in initial user-supplied objective function evaluation. FSOLVE cannot continue.
Undefined function or method 'mpower' for input arguments of type 'struct'
Error in 'fsolvefunction/MATLAB Fcn' while evaluating expression: Undefined function or method 'mpower' for input arguments of type 'struct'.
Kaustubha Govind
Kaustubha Govind on 16 Feb 2012
"A" is getting stored as a structure because the Save Format for your To Workspace block is configured to "Structure" - either change that to "Array", or access A by referencing the corresponding structure field A.signals.values.

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TAB
TAB on 14 Feb 2012
Trying writing variable A using stateflow chart with ml operator. Chart will update the variable in workspace at every sample time.
{ml.A=Data;}
O--------------------->O

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kamal kiki
kamal kiki on 15 Feb 2012
Hi TAB,
Please can you explain more. Where do I have to enter the code {ml.A=Data;} ???
I have tried typing this code in the command window but it is not working.

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Krishnendu Mukherjee
Krishnendu Mukherjee on 16 Feb 2012
one thing can be made;if u open the models through a global m-file using sim() command.for the first time when the first model will be exicuted the result will be passed to workspace through the function of the link given below. http://www.mathworks.com/matlabcentral/fileexchange/27106-putvar-uigetvar

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Muruganandham Subramanian
Muruganandham Subramanian on 16 Feb 2012
Hi kamal,
In your first model, by using To workspace & clock block, save the time in format of array, and the variable which you want to store in workaspace in same format.Then, by using From workspace block, in data parameter, create a matrix with time and variable for ur second model. Maybe it' ll work,try this.

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