depends on how you want to plot that matrix, and on what do you mean by its wrong.
When you plot a mtrix by simply calling
plot(A)
it'll plot a line for each column.
If you send axes it'l do the same in those axes
plot(gca, A)
now If there is no object called axes1, you will send an empty array to plot, and there will be an error.
If what you are trying to do is to take one column as x coordinates and the other as y coordinates do that:
plot(w, A(:,1), A(:,2))
