Result of the longitudinal field. (a) Full disk: longitudinal magnetogram at 00:00:00 on December 6, 2015, both images are 4096 × 4096 pixels. Left: prediction from neural network. Right: inversion result from VFISV. Two activity regions are marked with black boxes. (b)Active region NOAA AR12462 in (a). From left to right: prediction of the neural network; inversion result from VFISV; Residual of the prediction and inversion; Scatter diagram, the horizontal axis is the target, and the vertical axis is the prediction. (c) The active region NOAA AR12463 in (a). Same as (b).–