How to use get_param?

Hi!

I have a complex Simulink model in which I used 200-300 parameters.

My question comes with the following example: I am using a constant block in my Simulink model. 1) As you know, when you double click on the block you can see in the 'Main' tab the field 'Constant value' that can contain a value (e.g. 8) or a parameter name (e.g. 'my_parameter_name'). What I want is to get in Matlab workspace this name. I used: h=load_system('my_model') constant_blocks=find_system(h,'SearchDepth',2,'LookUnderMasks','all','FindAll','on','BlockType','Constant'); para_name=get_param(constant_blocks,'Value')

This will return the value of my_parameter_name. What I want is to get the name, not the numeric value. How can I do that??

[Kaustubha Govind]

That doesn't sound right. If the dialog contains a variable name for Value, get_param should return a string containing the same variable name (which is what you need). Perhaps you should verify that the corresponding Constant block does indeed use the variable name?

Answer 1

[Fangjun Jiang]

I think your find_system() line probably will return many blocks. You need to narrow it down.

Or just use a simple example, drag and drop a Constant block, double click it, type in "MyPara" as its value, then in Command Window, run

get_param(gcb,'Value')

[Diana Acreala]

Hmm...I'm using a lot of constant blocks, normally I want to get all the parameter names used, so I need to get first all my constant blocks as I did with:

constant_blocks=find_system(h,'SearchDepth',2,'LookUnderMasks','all','FindAll','on','BlockType','Constant');

[Fangjun Jiang]

That's fine. Then what is the problem using get_param()? Did you try it on a single Constant block to verify it first?

Answer 2

[Rajan]

constant_blocks=find_system(h,'SearchDepth',2,'LookUnderMasks','all','FindAll','on','BlockType','Constant'); const_value=[];

for i=1:length(constant_blocks)

const_value=[const_value get_param(constant_blocks(i),'Value')];

end

i hope this one works..

[Fangjun Jiang]

No. You don't need the for-loop. get_param() can take array of handles and return results in a cell array.

Answer 3

[Diana Acreala]

It gives me the same thing... numeriv values, not the name... is there another solution?

[Fangjun Jiang]

Try this. What do you get?

f14;

get_param(['f14/Nz pilot',char(10),'calculation/Constant'],'Value')

ans =

Uo

[Diana Acreala]

Nothing that helps me... What is this?

[Fangjun Jiang]

f14 is a Simulink model provided by TMW. I am showing that get_param() will be able to get the variable name, not numeric value. If you run the two lines, you will get the answer. That will solve the problem in your question. I don't understand why you are so struggle with such a simple task.