How do I display the current value of a variable in the matlab command window? In matlab I usually use disp(var) and it will output the variable value into the command window. However in the MATLAB function block if I were to enter disp('hello') it doesn't show any output in the command window. I am using matlab 2014b.
You idea for displaying output value in the command window is not a good approach to solve your issue. I would suggest you look at scope block if you'd like to see the value during simulation. Or use To Wrokspace block if you'd like to output the value into main workspace.
For debugging your code and design, read and use Simulink Debugger should be helpful.
Related
At the end of the execution of my program in MATLAB, the results, stored in a variable are being displayed in the command window. How to display the contents of a variable on to a different window?
Thanks!
Don't know whether this method suits your need, but try this: suppose variable x has the processed information.
strx = num2str(x);set(handles.textboxname, 'String', strx);
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 need to do a parser on my gui in matlab in which you can type your own function formula that will be used for computations. I came up with to make function that gets function from edit box as a string and saves it to m-file as a function. But any further calling changed file do not bring expected results if the first form of function were stored in memory. Do you have any other ideas to solve it?
Instead of writing the code to an m-file, take a look at the eval function.
I am building a reduced order observer in MATLAB. The matrices are calculated using functions/script files outside matlab and simulink function blocks are using these functions to calculate values.
The problem is that some commands like 'acker', 'place' etc which used to work on command window/function/script files are not working in simulink function block and showing errors.
I tried using simin block to take these matrices from workspace but it is also showing errors which I can't understand.
Thanks for your help.
If I get your question correctly then, from User defined functions, you could add a Matlab function block with the following code:
function fcn(in)
%#codegen
coder.extrinsic('acker', 'place')
# Now you can use acker, place so add more code.
I have observed a strange behavior in running the same code in a Matlab function and in the command window. It's already described in How does scoping in Matlab work? , but I don't understand how I could solve my specific problem.
The code is the following:
exporteddata.m %File created by an external program
%to export data in Matlab format
surface = struct('vertices', [...]) ;
%I can't specify in the external program
%the name of the variable, it's always "surface"
My actual code is:
myfunction.m
function output = myfunction(input)
load(input);
n = size(surface.vertices);
....
When running
myfunction('exporteddata.m');
I get the following error:
??? No appropriate method, property, or field vertices for class hg.surface.
When running the same instructions from the command window or in debug mode, the code works well.
How can I specify in the function that I need the variable surface present in the workspace, not the Matlab function?
First of all, I must point out that surface is a built-in function in MATLAB, so overloading it is just... bad. Bad, bad, BAD!
Having said that, the MATLAB interpreter does a pretty good job at resolving variable names and usually tells them apart from function names correctly. So where's your problem, you ask?
I believe that you're using the wrong function: load is a function that loads data from MAT files into the workspace. It is not fit for m-files. By not executing "exportedata.m" properly, surface has never been created as a variable, so MATLAB identifies it as a function name. If you want to execute "exportedata.m", just type:
exportedata
and if you want to run the file with the filename stored in input, you can use run:
run(input)
By executing run(input) from within myfunction, surface should be created in myfunction's local scope, and it should work.
EDIT:
I've just tested it, and the interpreter still gets confused. so the issue of the variable name resolution remains. Here's a workaround:
function output = myfunction(input)
surface = 0; %// <-- Pay attention to this line
run(input);
n = size(surface.vertices);
Predefining surface allows the interpreter to identify it as a variable throughout your entire function. I've tried it and it works.