Figure 2
From: Short term Heart Rate Variability to predict blood pressure drops due to standing: a pilot study

Histogram of Residuals. Histogram of residuals, which represents the distribution of the prediction errors. Each bar refers to the % of predictions with the error in mmHg reported below the bar. The bar in the center indicates that 25% of predictions have an error = 0; the 3 central bars indicate that 55% of predictions estimate ΔBP with an error smaller than ±2 mmHg.