EWs of Hα, Hβ, [N II] and [O III] predicted by the ANN_R compared to SDSS testing sample. The ANN_R is trained with the CALMa set. The color-code represents the probability density function defined by a Gaussian kernel (right panel) and the redshift of the objects (left panel). The histograms in are normalized to one and show the relative difference between both values. Black and blue numbers are the median and the median absolute deviation of the difference. Black and grey dashed lines on the left are lines with slope one and the best linear fit respectively. We perform a sigma clipping fit with σ = 3 to exclude outliers. The red dashed line represents the median.