prepend a list to a matrix in matlab

Question

i wanted to ask this:

If i have this matrix:

magnetT=NaN(Maxstep,2);  

and want to prepend to it the "{0 1}"

how can i write it?

Also,if i have this in mathematica in a loop:

magnetT[[i]] = {T, Apply[Plus, Flatten[mlat]]/L2}

the equivalent in matlab isn't this???

magnetT(i,2)=[T ,sum(mlat(:))./L2];

because it gives me :Subscripted assignment dimension mismatch.

Error in ==> metropolis at 128 magnetT(i,2)=[T,sum(mlat(:))./L2];

Thanks

Answer 1

I'll attempt to answer your first question both questions.

You asked about prepending the NaN array to {0,1} which is a cell array. Any data objects can be readily bundled into a cell array:

>> anyData = NaN(3, 2);
>> newCellArray = {anyData; {0, 1}}

newCellArray = 

    [3x2 double]
    {1x2 cell  }

If you are instead trying to concatenate the results into a numeric matrix, the following will help:

>> Maxstep=3;
>> magnetT=NaN(Maxstep,2);
>> newArray = [magnetT; 0 1]

newArray =

   NaN   NaN
   NaN   NaN
   NaN   NaN
     0     1

For your second question, MATLAB is complaining about trying to store a vector in one element of magnetT. When computing:

magnetT(i,2)=[T ,sum(mlat(:))./L2];

the right-hand side will create a vector while the left-hand side is trying to store that vector where a scalar is expected. I don't know exactly what you're trying to achieve and I'm not very familiar with Mathematica syntax but perhaps you need to do this instead:

magnetT(ii,:) = [T sum(mlat(:))./L2];

or, in other words:

magnetT(ii,1) = T;
magnetT(ii,2) = sum(mlat(:)) ./ L2;