I am solving hybrid control problems using Drake with Gurobi solver. I want to get the final root relaxed solution (after presolve and auto cut generation). I tried writing log files, but the log file doesn't print out every iteration and I couldn't get the best relaxed objective bound after presolve and cut generation.
Get root node relaxation solution
This post shows how to retrieve the value I want, but I am not sure how to change the code to use it in Drake.
Thanks in advance.
In GurobiSolver, we provide adding callback functions for mixed-integer program, you can check AddMipNodeCallback or AddMipSolCallback
Related
I'm working on a script to convert a Simulink library to a plain model, meaning it can be simulated, it does not auto-lock etc.
Is there a way to do this with code aside from basically copy-pasting every single block into a new model? And if it isn't, what is the most efficient way to do the "copy-paste".
I was not able to find any clues as how to approach this problem here, or on Google, or on the official documentation or on the MathWorks forum so I'm at a loss on how to proceed.
Thank you in advance!
I don't think it's possible to convert a library to a model, but you can programmatically add library blocks to models like so:
sys = 'testModel';
new_system(sys);
open_system(sys);
add_block('Simulink/Sources/Sine Wave', [sys, '/MySineWave']);
save_system(sys);
close_system(sys);
sim(sys);
You could even use the find_system command to list all the blocks in a library and then loop through them all and create a new model for each using the above code.
I am trying to run Omnet++ and matlab software in parallel and want them to communicate. When Omnet++ is running, I want to update the position of the node and for that I want to edit the .ned and .int files with matlab results continuously. During simulation I want to generate the result file using the updated files. I want just to update the position and don't want to add or delete any node. Please suggest me a way for proceeding?
matlab_loop
{
matlab_writes_position_in_ned_file;
delay(100ms);
}
omnet_loop
{
omnet_loads_ned_and_simulates;
//sca and vec should update;
delay(100ms);
}
Thank you.
NED and Ini files are read only during initialization of the model. You can't "read" them again after the simulation started. On the other hand, you are free to modify your parameters and create/delete modules using OMNeT++'s C++ API. What you want to achieve is basicaly: set your node position based on some calculations carried out by matlab code. The proper way to do it:
Generate C code from your matlab code.
Link that code to your OMNeT++ model
Create a new mobility model (assuming you are using INET) that is using the matlab code
What you are looking for seems to be more of a project rather than a question/problem which can be solved in Q&A site like stackoverflow.
Unfortunately, I have little understanding of matlab and V-REP to provide you a satisfactory answer. However, it seems that you will need to play around with APIs in lower levels.
As an example of coupling different simulation tools to form a simulation framework in case of need consider reading this paper and this
Also note the answer given by #Rudi. He seems to know what he is talking about.
I am trying to run compiled MATLAB code (by mcc) from inside MATLAB in a way that I can avoid using another license that is required by the compiled code. We need this because we run this same specific code part again and again and execution is stuck due to license waiting. We don't want to buy tons of this specific license just to mass run the same part. Is there any way to do this? tutorial?
Is it possible to compile a .m file to dll/so and wrap it like a mex and call it from MATLAB on the fly? How would I pass and retrieve complex arguments?
According to
http://www.mathworks.de/products/compiler/description3.html
creating shared libraries should well be possible.
Concerning passing and retrieving complex arguments:
If you plan to use mex, I'd assume you should be able to call the shared-library "main"-function with any arguments you'd like, using the mxArray type that you'll have to use anyway.
To run the MATLAB-compiled code in MATLAB, you want codegen, part of the MATLAB Coder. See this blog post on generating C code from MATLAB. The alternative, deploying code with mcc/mbuild and then reloading it into MATLAB with loadlibrary is rather contorted, and I wouldn't advice it.
Let us say that I have a Matlab function and I change its signature (i.e. add parameter). As Matlab does not 'compile' is there an easy way to determine which other functions do not use the right signature (i.e. submits the additional parameter). I do not want to determine this at runtime (i.e. get an error message) or have to do text searches. Hope this makes sense. Any feedback would be very much appreciated. Many thanks.
If I understand you correctly, you want to change a function's signature and find all functions/scripts/classes that call it in the "old" way, and change it to the "new" way.
You also indicated you don't want to do it at runtime, or do text searches, but there is no way to detect "incorrect" calls at "parse-time", so I'm afraid these demands leave no option at all to detect old function calls...
What I would do in that case is temporarily add a few lines to the new function:
function myFunc(param1, param2, newParam) % <-- the NEW signature
if nargin == 2
clc, error('old call detected.'); end
and then run the main script/function/whatever in which this function resides. You'll get one error for each time something calls the function incorrectly, along with the error stack in the Matlab command window.
It is then a matter of clicking on the link in the bottom of the error stack, correct the function call, and repeat from the top until no more errors occur.
Don't forget to remove these lines when you're done, or better, replace the word error with warning just to capture anything that was missed.
Better yet: if you're on linux, a text search would be a matter of
$ grep -l 'myFunc(.*,.*); *.m'
which will list all the files having the "incorrect" call. That's not too difficult I'd say...You can probably do a similar thing with the standard windows search, but I can't test that right now.
This is more or less what the dependency report was invented for. Using that tool, you can find what functions/scripts call your altered function. Then it is just a question of manually inspecting every occurrence.
However, I'd advise to make your changes to the function signature such that backwards compatibility is maintained. You can do so by specifying default values for new parameters and/or issuing a warning in those scenarios. That way, your code will run, and you will get run-time hints of deprecated code (which is more or less a necessary evil in interpreted/dynamic languages).
For many dynamic languages (and MATLAB specifically) it is generally impossible to fully inspect the code without the interpreter executing the code. Just imagine the following piece of code:
x = magic(10);
In general, you'd say that the magic function is called. However, magic could map to a totally different function. This could be done in ways that are invisible to a static analysis tool (such as the dependency report): e.g. eval('magic = 1:100;');.
The only way is to go through your whole code base, either inspecting every occurrence manually (which can be found easily with a text search) or by running a test that fully covers your code base.
edit:
There is however a way to access intermediate outputs of the MATLAB parser. This can be accessed using the undocumented and unsupported mtree function (which can be called like this: t = mtree(file, '-file'); for every file in your code base). Using the resulting structure you might be able to find calls with a certain amount of parameters.
i want to change function variable at each step in a for loop in matlab.
i take these steps:
i created my mfile function
function [jfun,fun]=air(x,vt,ty,tz,p2,y0)
jfun=[(cos(tz)*cos(ty)*vt/9.81)*(1-exp(-9.81*x(2)/vt)),...
x(1)*cos(tz)*cos(ty)*exp(-9.81*x(1)/vt);
(-vt*sin(tz)*cos(ty)/9.81)*exp(-9.81*x(1)/vt),...
(x(1)*sin(tz)*cos(ty)*+vt)*exp(-9.81*x(1)/vt)];
fun=[(x(1)*cos(ty)*cos(tz)*vt/9.81)*(1-exp(-9.81*x(2)/vt))-p2;...
(vt/9.81)*(x(1)*sin(tz)*cos(ty)+vt)*(1-exp(-9.81*x(2)/vt))-vt*x(2)+y0];
end
and then i used newtonSys command:
ty=rad(-23)
tz=rad(15)
p2=1.8
vt=8.4925
y0=0.2
myfun=#(x)air(x,vt,ty,tz,p2,y0)
x=newtonSys(myfun,[15 5],0.000001,0.000001,500,1)
and matlab answer:
Error in ==> Untitled18 at 7
x=newtonSys(myfun,[15 5],0.000001,0.000001,500,1)
i guess that its because of wrong use of function handle and for my function i have to use another command or i have to use another method for solving 2nonlinear equation.
First, you haven't displayed the entire error. MATLAB should tell you what the actual error is, so unless you tell us that, we won't know what's wrong.
Secondly I don't see newtonSys in my system, or in the online MATLAB documentation. So most likely it is an external program, which most people here might not be familiar with. The closest I found from a quick Google search was this, which is an implementation of Newton's method for approximating the root of a non-linear system of n-equations. Are you using the same file? If so, if you look at the comments, it says that you need to pass the function as a string. So you'd have to pass myfun as 'myfun'.
If not, could you edit your question and add the contents of the function that you're using? Without these, it's near impossible to answer your question.