Correlation coefficient tables. Each table has a colour scale that represents the correlation coefficient, which ranges from −1 (negatively correlated) through 0 (no correlation) to 1 (positively correlated). This number informs how each spectroscopic parameter is correlated with the others. The top table shows the coefficients for a K-type star (δ Eri) and the bottom table for a F-type star (HD 49933). The vertical and horizontal axes for both depict the eight spectroscopic parameters from the SAPP spectroscopy module.