One-to-one relation between the CNN trained labels (y-axis) and the input labels (x-axis, APOGEE DR16 data). The training sample is plotted with blue circles, while the test sample is shown with orange crosses. The x- and y-axis parameters are presented as histograms with a logarithmic scale. For each parameter, a typical mean difference and scatter are computed in both sets. We plotted the difference Δ between the CNN trained labels and the APOGEE DR16 input labels with the same symbols and colours, and its histogram with a logarithmic scale.