I found mathscript can do this,but it seem too slow.
So I want to use matlab to create a dll file used by labview,but all information I can find just how dll could used in C++,but C++ also must use the .lib file ,I am concerned labview could not use lib. file.
So can I use the .dll in labvew,and how?Is there anyother way to use matlab source code in labview without matlab?
You will need to purchase the MATLAB Compiler which is quite expensive unless you are a student.
You can also call the MATLAB application (if it's installed) using the MATLAB Script Node (which is different than Mathscript) - see here
Another alternative is Python's Numpy which I personally picked up quickly coming from a MATLAB background. If you want to go down that route I can give you further advice on how to integrate with LabVIEW.
Related
I'd like to use a Continuous wavelet transform (CWT) function in my octavegui code.
in Octave gui CWT is not available - is there equivalent .pkg to use a cwt?
fwt is available in the ltfat.pkg- but this seems to be something different than cwt.
According to the pdf from Prusa a form of a CWT is a Morlet or a mexican hat ("Continuous Wavelet Transfom – CWT (Morlet, Mexican hat, . . . ).= - is it possible to use a Morlet function in Octave? or is this something different?
any suggestions? (I am not a mathematician)
thank You
If none of these functions cover your needs, then you have two other options:
Use a c++ or java package within octave. Octave has external interfaces for both.
Use a simple python / julia / whatever scripts to perform specific calculations using your favourite wavelet package natively in that language, and use .mat converters to pass data (e.g. scipy.io.loadmat / savemat in python, and MAT.jl for julia) in and out of octave. Octave provides a 'python' function for executing python scripts for convenience (but this is no more than a nicely wrapped system call).
In any case, unfortunately that does mean you would need to know a bit of python / c++ / java respectively.
You can find a nice list of wavelet packages here.
Another thing you could try, is scilab. It is similar to octave (though not identical), and provides a wavelet package. There's also a module which allows intercommunication between octave and scilab.
Do have a look at the octave forge list first though. It's been a while, but last time I worked with wavelets I remember those covered my needs more than adequately.
PS. I did not mention Wavelab above, because their website does not mention this, and I don't know if it actually works on octave. Also, it seems a bit outdated. But in theory there's no reason why it wouldn't work, might as well give their .mex files a try if it seems relevant to you.
PS2. If something works for you, feel free to leave a comment here for future readers.
I need help in using the MVGC (Multivariate Granger Causality) Toolbox for MATLAB.
I tried to execute the demo code which is provided here, but the code is not executing properly, since many of the functions (e.g rng_seed(), var5_test()) do not exist in MATLAB.
I searched for those in the MATLAB support but was unable to find any information regarding them.
The short answer is: it's likely not related to the specific MATLAB version, and you should just include the toolbox in your search path.
The functions aren't identified because they're not part of the MATLAB installation, but are rather included in the toolbox itself (which you should download manually). Then, for them to be recognized, download the toolbox, extract it, and add the contents of the toolbox (including subfolders) to your MATLAB path.
Specifically regarding the functions you mentioned, they're found here:
var5_test -> \mvgc_v1.0\demo\var5_test.m
rng_seed -> \mvgc_v1.0\utils\rng_seed.m
I'm interested in hooking up AMPL with Matlab to obtain objective values, gradients, and Jacobians to test ideas for optimization algorithms on a wide set of problems. I'm aware that I can use amplfunc.mex or spamfunc.mex to do this; however, I'm having trouble compiling the .mex files using the old netlib files on Windows. The link also given in a previous question:
Using MATLAB with AMPL
is outdated. Does anyone know where I can obtain these .mex files or offer any alternative solutions? Thanks in advance.
The mex files amplfunc.c and spamfunc.c are still available at http://www.ampl.com/netlib/ampl/solvers/examples. We aren't aware of a reason why these wouldn't compile, but if you are having trouble you could write to the AMPL user forum, ampl#googlegroups.com. Be sure to explain which function you are using and to give the complete text of any error messages you see.
I'm trying to get very basic network functionality with Matlab Coder (I need to turn it into C code). However, all the network classes and objects I try arn't supported by Coder. It seems unreasonable that Matlab would completely neglect networking entirely with this tool. Is there some method of sending data over a network that DOES work with coder?
I'd prefer TCP, but UDP or anything else that will actually send/receive data will work, as long as it is compatible with Coder.
This answer assumes that the DSP System Toolbox is not available. If it is, the System Objects dsp.UDPSender and dsp.UDPReceiver may be considered.
Since the final goal is to generate C code, and because network I/O is usually done via a library, a good approach would be to integrate external C code that does the network I/O into your MATLAB Code. The basic way to call an external C function is using coder.ceval and the process is explained here.
Recommended Steps
Write C(++) functions implementing the behaviour you need or find a C library providing the necessary functionality. Assume we implement the function externalUDPSend in the files externalUDPSend.h/.c.
Write one or more MATLAB functions that call your C(++) functions using coder.ceval as shown in the linked documentation. These will serve as a wrapper around your external code, and will expose the C(++) code to MATLAB. Something like callfoo in the linked example will work:
function y = useExternalUDP(x)
%#codegen
if coder.target('MATLAB')
% Running in MATLAB. Use standard MATLAB
% network I/O code here
...
else
% Generating code. Call external code/library
% Include header for external code
coder.cinclude('externalUDPSend.h');
% Set the type of the output. Assume double scalar
% Change the RHS to match the return type
y = 0;
y = coder.ceval('externalUDPSend',x,numel(x));
end
Develop your project. Call the wrapper function(s), which will work in MATLAB and in the generated code because of the use of coder.target.
Generate a MEX function using something like:
codegen useExternalUDP -config:mex externalUDPSend.c -args ...
The generated MEX function serves as the MATLAB interface to your custom code so there is no need to hand write a MEX interface. MATLAB Coder will generate all of MEX interfacing logic for you. Then test that MEX function in MATLAB. Testing the MEX function is important because runtime errors like out of bounds indexing, using features not supported for code generation, etc. can be detected and reported in MEX. These checks are removed from generated standalone code.
Generate standalone code and either let MATLAB Coder compile it to a library or deploy the code to an external IDE and compile it there.
Integrating External Libraries/Encapsulating Dependencies
Note that you may also need to link in libraries if you choose to use an existing network I/O library, or you may need to modify the build of the generated code. You can either use coder.updateBuildInfo or coder.ExternalDependency to achieve this in your MATLAB Code.
Further Reading
The file reading example shows some more advanced custom code integration tools such as coder.ref, coder.opaque, and dealing with C strings from MATLAB code when calling external code. Note that the MATLAB functions fprintf and fread are supported for code generation so this example is meant to be instructive rather than a necessity for doing file I/O.
If you have the DSP System Toolbox, the System Objects dsp.UDPSender and dsp.UDPReceiver are supported for code generation since they are listed in the comprehensive list of supported functions.
The code generated from them relies on prebuilt libraries shipped with MATLAB and will run on desktop platforms compatible with those libraries. See the documentation for the UDP Receive block for more details.
As you may know, extrinsic functions are not outputted during the code generation process. Are there alternatives to these functions and/or solutions to this problem? My code generation error report is shown below :
Code Generation Error Report
I am surprised that I can't output size and rgb2gray either. Since these are essential to my program, I cannot avoid them.
Help will be much appreciated!
This is a good question, and I see similar questions fairly frequently. As I started using MATLAB Coder, one of the biggest pitfalls was the constant search for supported functions. I sympathize with your frustration, and I have a few tips, having been through this.
First, to your direct question, while imread isn't supported by Coder, size and rgb2gray are. Probably Coder is complaining about these because they have been passed mxArrays from the call to imread, which is fine when it is extrinsic, but not ok for separate generation. That's just a guess. A very useful tool in writing code is the list of Coder supported functions: List of Functions supported in MATLAB Coder
But even with those two, to replace imread is not a tiny task. You'll have to find another library that supports the particular file you're working with, and then stitch that in using coder.ceval. Alternatively, if you can find a pure MATLAB implementation of it, that might help.
Are you targeting a pure C library or a MEX file? If you intend to use this code within the MATLAB environment, you can always use imread separately and then pass the data.
And now to some more general observations: MATLAB Coder isn't a perfect MATLAB to C translation system. It's extremely powerful, and I've been able to write some very large projects with it, but if what you want is the ability to run any MATLAB code without MATLAB around, you should look at MATLAB Compiler, a different add-on. There's a very good Q and A about this here: MATLAB Compiler vs MATLAB Coder
When writing projects in MATLAB Coder, it's really best to start from scratch, knowing you're targeting C code ultimately. There are so many gotchas in the conversion from MATLAB to C that you have to be always vigilant while writing the MATLAB code.
One tool that helps is to right-click on a file in the "Current Folder" list that usually resides on the left-side of the main window, and select "Check Code Generation Readiness." You'll get a great report of potential problems in the file. I recommend using this often.
Another useful tool is to always put the %#codegen tag into your code. This alerts the MATLAB editor that the .m file is intended for code generation, so it provides extra context-sensitive information while you're writing the file. This helps enormously.
The most commonly missing functions for code generation are file IO functions. There are some good reasons for this, but it's frustrating nonetheless.
When you stitch in external C code, you use the coder.ceval function, which can provide excellent access to external libraries. Using this well is a whole other topic, outside the scope of this question.
If you can indicate exactly what kind of files you're interested in reading (PNG, BMP, TIFF, etc.) perhaps someone may be able to identify a good external library for you to use.