Discretization
xi = (i+1)h + xmin i= –1, 0,…, m–1, m
yi = (j+1)h + ymin j= –1, 0,…, n–1, n
same discretization in x and y: h = (xmax – xmin)/(m+1) = (ymax – ymin)/(n +1)
Boundaries (??)
i = –1, j = 0,…,n–1
i = m, j = 0,…,n–1
i = 0,…,m–1, j = –1
i = 0,…,m–1, j = n *)