Fig. 4

Comparison of precision and accuracy between a clock based on the CpGs common to 450 K and EPIC and a clock on all the CpGs on EPIC. a Scatter plot of the Pearson correlation (r) in the test set against the sample size of the training set. b Scatter plot of MAD in the test set against the sample size of the training set. In panel (a), we fit the smoothing splines of the Fisher’s Z-transformed r values on the sample size, derived the confidence intervals, and inverse-transformed them. In panel (b), we fit the smoothing splines of MAD values on the sample size without transformation. The black dots refer to the clock based on the CpGs common to 450 K and EPIC, and the red dots refer to the clock based on all the CpGs on EPIC