Interaction between MATLAB 32bit and MATLAB 64bit

PROBLEM

I have two tools written in MATLAB (I am not the author):

1. the first allows me to retrieve some data from a SQL database, but it works only on MATLAB 64bit (I have MATLAB 2016b 64bit).

2. the second uses the data retrieved from the first tool and, through a DLL compiled on a 32bit system, it gets some outputs. As said, this tool works only MATLAB 32bit (I have MATLAB 2013a 32bit).

What I would like to do is:

1. get the data from SQL, in MATLAB 64bit

2. "send them" in some way to MATLAB 32bit

3. run the tool on MATLAB 32bit

4. "return" the outputs from MATLAB 32bit to MATLAB 64bit

I know a solution may be found using IPC mechanisms, but I am not sure how to find them or how to use them in MATLAB. Does anyone ever worked with this kind of stuff?

Looking into the MATLAB documentation I saw that it is possible to create a **COM object**, but I am not sure how to use it to run some functions in MATLAB 32bit.

SOLUTION

Unfortunately the solutions below did not help to solve the problem. Though, I managed to get the results I wanted using system commands. The correct answer can be found at the link below.

StackOverflow - Interaction MATLAB 32bit and 64bit

Answer 1

[Guillaume]

I'm not clear why step 1 requires a particular bitness. The majority of databases will provide a 32-bit and 64-bit ODBC driver. In fact, looking at my computer, I've got more 32-bit drivers than 64-bit ones.

You could indeed use COM to communicate between the 32 bit and 64 bit matlab, as long as they're different versions. Probably... it's not something I've ever tested. You'd use the version dependent ProgID to locate the 32-bit version of matlab.

So, from the 64-bit matlab, it would look like:

matlab32 = actxserver('Matlab.Application.8.1');  %8.1 is R2013a according to wikipedia
matlab32.Execute('some script');
result = matlab32.Feval('Some function', input1, input2);
matlab32.Quit

But maybe it's time to rewrite these tools. R2013 is getting long in the tooth.

[Federico]

Hi Guillaume,

thanks a lot for your answer! I did not investigate the 32-bit/64-bit ODBC driver situation. I am not sure how to fix that, but I will try also that path eventually.

Could you please explain me what you mean for 'some script' and 'some function'?

Let's say I have a function in my folder called 'runScript.m' and it is like

function output = runScript(input)
    output = function2(input)
end

The real function has inside a function (represented by function2 in the example above) which uses a 32-bit DLL and return an output.

How should I implement it along with your example?

[Guillaume]

With that function signature, it would be:

%from matlab 64 bit
output = matlab32.Feval('runScript', 1, input);  %1 to say that the function has 1 output
output = output{1};  %Feval always return a cell array containing all the ouputs

As another example, if you wanted to use Feval to call the matlab function ndgrid to build two arrays:

out = matlab32.Feval('ndgrid', 2, 1:4, 1:5);  %2 outputs
x = out{1}; y = out{2};  %could also be written [x, y] = deal(out{:});
%this is equivalent to:
%[x, y] = ndgrid(1:4, 1:5)

[Federico]

If I try to run the second function you mentioned it works perfectly. If I run my function I get this error

Error using COM.Matlab_Application_8_1/Feval
Invoke Error, Dispatch Exception:
Source: Matlab.MLApp
Description:

I tried even to modify it to a basic one like

function output = runScript(input)
    output = input * 2;
end

but it throws the same error. The runScript function is in the same folder I am working in, so I am not sure what I am missing.