MATLAB Central Newsreader - Sharing data between GUIs without using workspace

Sharing data between GUIs without using workspace

M.Mohsin Siraj — Fri, 05 Sep 2008 03:15:03 -0400

Guyz
i wanna know is there any method by which i can exchange my
variables from one GUI to other GUI?
If i use workspace in between, After making the .exe file
of my GUI, how will then it works??
SO any method knidly guide me. plz

Re: Sharing data between GUIs without using workspace

M.Mohsin Siraj — Fri, 05 Sep 2008 03:22:02 -0400

"M.Mohsin Siraj" <stylismoh@mathworks.com> wrote in message
<g9q87n$kc8$1@fred.mathworks.com>...
> Guyz
> i wanna know is there any method by which i can exchange
my
> variables from one GUI to other GUI?
> If i use workspace in between, After making the .exe file
> of my GUI, how will then it works??
> SO any method knidly guide me. plz

I am using "Guide" to design the GUI...

thnx n Regards,

Re: Sharing data between GUIs without using workspace

Walter Roberson — Fri, 05 Sep 2008 04:42:04 -0400

M.Mohsin Siraj wrote:

> i wanna know is there any method by which i can exchange my
> variables from one GUI to other GUI?
> If i use workspace in between, After making the .exe file
> of my GUI, how will then it works??

Do I understand correctly that you plan to be using two
independent .exe files and you want to communicate variables
between them?

If so then you will have to use I/O to write the values of
the variables out from one and read (a copy of) the values
in the other. You might be able to make the process more
efficient by using memory mapping, but that would be just an
optimization. I don't think you would be able to "share"
variables between the two in the sense that changing the
value of the variable in one of them would automatically
change the value of the variable in the other (though I would
not rule out that possibility -completely-.)

--
Q = quotation(rand);
if isempty(Q); error('Quotation server filesystem problems')
else sprintf('%s',Q), end

Re: Sharing data between GUIs without using workspace

carlos lopez — Fri, 05 Sep 2008 12:10:17 -0400

Walter Roberson <roberson@hushmail.com> wrote in message <wM2wk.67483$hx.28408@pd7urf3no>...

> I don't think you would be able to "share"
> variables between the two in the sense that changing the
> value of the variable in one of them would automatically
> change the value of the variable in the other (though I would
> not rule out that possibility -completely-.)
It depends on the underlying OS. I am aware that such mechanism exist at least in LINUX, and one example is the one which allows changing the language environment and it might affect immediately all the (properly coded) applications.
BTW: I do not interpret the request from the user that he plans to connect two different exe applications. IMHO he plans to connect two windows opened by the same application. But I might be wrong..
Regards
Carlos

Re: Sharing data between GUIs without using workspace

Jeremy Smith — Fri, 05 Sep 2008 15:17:02 -0400

If you're using one GUI which spawns other GUIs then yes, you can use the base workspace. When I created my GUI I was surprised to find that there is a base workspace but it worked just as if I were in Matlab. I designed my GUI programmatically so I'm not sure if GUIDE will have any other difficulties.

Re: Sharing data between GUIs without using workspace

Walter Roberson — Fri, 05 Sep 2008 16:41:32 -0400

carlos lopez wrote:
> Walter Roberson <roberson@hushmail.com> wrote in message <wM2wk.67483$hx.28408@pd7urf3no>...

>> I don't think you would be able to "share"
>> variables between the two in the sense that changing the
>> value of the variable in one of them would automatically
>> change the value of the variable in the other (though I would
>> not rule out that possibility -completely-.)

> It depends on the underlying OS. I am aware that such mechanism exist at
> least in LINUX, and one example is the one which allows changing the language
> environment and it might affect immediately all the (properly coded) applications.

In computer languages such as C, you can have pointer variables that can point
into a shared memory (or memory mapped) block of memory; if multiple processes
share the block, then a change by one of the processes of the content of the
block will affect the other processes "automatically" (provided that in C
or C++ you declared the variables to be 'volatile' so that the compilers do
not rely on a copy of the value they have stuffed into a register and do
not make optimizations that depend upon the value of the variable being
a constant within a loop.)

But in Matlab, there are no user-level pointers and no commands that I know of
to place variables within shared areas (you would have to disable copy-on-write
for such variables, of course.) You might perhaps be able to do it at the
mex level by requesting an array header and setting its data pointer as
you wanted into the shared area, but that would have problems at least as great
as those that occur when you malloc() space for a variable in C. I believe that
I've read postings from people who say that you can do that if you are careful;
I have never looked at the details myself. I suspect the Matlab routines are not
designed with the expectation that they might be dealing with volatile memory.

--
Q = quotation(rand);
if isempty(Q); error('Quotation server filesystem problems')
else sprintf('%s',Q), end