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From: Ashish Uthama on 17 Mar 2010 15:19
On Wed, 17 Mar 2010 04:47:22 -0400, Sergio <serjossj(a)inwind.it> wrote:

> "Ashish Uthama" <first.last(a)mathworks.com> wrote in message <
>> Serjo,
>> Could you explain your setup some more?
>> It is not clear if you are trying to pass a structure from C++ Mex
>> file to MATLAB. Or, if you have a C++ application which uses a MATLAB
>> code compiled into a DLL. I believe its the latter, in which case,
>> yes, the DLL will create its own instance of 'MATLAB' (Look up MCR in
>> the doc). It will not have access to your interactive MATLAB session's
>> workspace.
>> Note that mxArray are C/C++ source code for Mex files for use in a
>> MATLAB session, mwArray are for C++ source code for drivers to use
>> MATLAB compiled DLLs
>>
>
> Hi,
> I've a MATLAB code compiled in a dll so i need to convert that struct as
> input argument.
> I managed to create that struct directly in an mwArray but, i'm having
> some problem with filling it. Here is the code:
>
> const char* fields[] = {"latitude", "longitude", "altitude"};
> mwArray entitylist(1, Total_entities, 3, fields)
> mwArray temp(1,1,mxDOUBLE_CLASS);
> double a;
>
> for (int i_list = 1; i_list<=Total_entities; i_list++)
> {
> a = latitude;
> temp.SetData(&a,1);
> entitylist.Get("latitude",1,i_list).Set(temp);
> }
> while filling mwArray entitylist, just last value is loaded even if
> column index is specified by i_list. (ie, if i've Total entities equal
> to 3, just last latitude value is loaded into entitylist.latitude and it
> fills all 3 columns. Am i doing something wrong?
>
> Thx

Your code appears to be doing exactly what you observe.
I dont see the value of 'a' changing inside the loop, I would expect
entitylist.latitude to have same valued elements.
From: Sergio on 18 Mar 2010 05:59
> > const char* fields[] = {"latitude", "longitude", "altitude"};
> > mwArray entitylist(1, Total_entities, 3, fields)
> > mwArray temp(1,1,mxDOUBLE_CLASS);
> > double a;
> >
> > for (int i_list = 1; i_list<=Total_entities; i_list++)
> > {
> > a = latitude;
> > temp.SetData(&a,1);
> > entitylist.Get("latitude",1,i_list).Set(temp);
> > }

> Your code appears to be doing exactly what you observe.
> I dont see the value of 'a' changing inside the loop, I would expect
> entitylist.latitude to have same valued elements.


but i_list change within for cycle and, with each for cycle i've a different latitude value.
so, i would set a different value of latitude (this is not an array but change accordingly to entity, outside for cycle).
So, i thought i might fill it just by chosing row and column index.
btw, i found a mode to handle it:

a = latitude;
temp.Get(1,i_list).SetData(&a,1);
entitylist.Get("latitude",1,i_list).Set(temp.Get(1,i_list));

in this way it seems struct is corerctly loaded.
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