dolfin team mailing list archive

[Hatef Monajemi <hmonajem@xxxxxxxxxxxxxxxxxxx>]

On Sun, 2008-06-22 at 23:51 +0200, Anders Logg wrote:
> On Sat, Jun 21, 2008 at 05:29:14AM -0400, Hatef Monajemi wrote:
> > 
> > Hi
> > Isn't this code supposed to work? It gives me "invalid lvalue in 
> > assignment" error while compiling. How should I assign the elements of 
> > a Matrix???
> > 
> > //-------------------------------
> > int main()
> > {
> > 
> > 
> > for(i=0; i<nens; i++)
> > .
> > .
> > .
> > real* values = new real[nstat];
> > u1.interpolate(values);
> > 
> > Matrix S(nstat,nens);
> > 
> > for(int j=0;j<nstat;j++)
> >   {
> >     S(j,i)=values[j];
> >   }
> >  
> > }
> 
> Sorry, this doesn't work yet.
> 
> We can easily fix this in the GenericMatrix interface by adding an
> auxiliary class MatrixEntry (which just holds (i, j) and a reference
> to the matrix) and have operator() return that, then overload
> operator= in MatrixEntry to assign to the matrix.
> 
> We had this in DOLFIN 2-3 years back but the linear algebra has gone
> through several reimplementations since then...
> 
> Until this has been implemented, you can use the setitem() function.

Well, I am trying setitem() and as I can get from the GenericMatrix.h it
should have a form like :
-----------------------
Matrix S(nstat, nens);
S.zero();
for(i=0; i<nens; i++)
for(int j=0;j<nstat;j++)
{
S.setitem(ji, values[j]); 
}
-------------------------
But it is not working either. am I doing a stupid mistake using
setitem() function? it gives me "ji was not declared in this scope".  
sorry for bothering you.

> And please file a bug report for this. Mark it as "enhancement".

I did it. I also have the same problem when using "Vector" class. I can
not assign values to the vector. does it have the same bug?

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