Adjoint operators |
In both the forward and the adjoint operation, each data coordinate is examined and the nearest mesh point (the bin) is found. For the forward operator, the value of the bin is added to that of the data. The adjoint is the reverse: we add the value of the data to that of the bin. Both are shown in two dimensions in subroutine bin2().
for (id=0; id < nd; id++) { i1 = 0.5 + (xy[0][id]-o1)/d1; i2 = 0.5 + (xy[1][id]-o2)/d2; if (0<=i1 && i1<m1 && 0<=i2 && i2<m2) { im = i1+i2*m1; if (adj) mm[im] += dd[id]; else dd[id] += mm[im]; } } |
Adjoint operators |