Table 2.

Results of analyzing correlation coefficients among certain factors of natural light: clear days.

Correlation Coefficient	SWR	MWR	LWR	tristimulus_X	tristimulus_Y	tristimulus_Z	color_coordinate_x	color_coordinate_y	Illuminance	CCT
SWR (Short $\mathrm{Wavelengh} \mathrm{Ratio})$	1	−0.993	0.923	0.929	0.931	0.956	− 0.99	− 0.996	0.931	0.997
MWR ($\mathrm{Middle} \mathrm{Wavelengh} \mathrm{Ratio})$	−0.993	1	−0.961	−0.931	−0.933	−0.942	0.998	0.982	−0.933	−0.993
LWR ($\mathrm{Long} \mathrm{Wavelengh} \mathrm{Ratio})$	0.923	−0.961	1	0.885	0.886	0.86	−0.963	−0.896	0.886	0.928
tristimulus_X	0.929	−0.931	0.885	1	1	0.987	−0.921	−0.914	1	0.92
tristimulus_Y	0.931	−0.933	0.886	1	1	0.987	−0.923	−0.916	1	0.922
tristimulus_Z	0.956	−0.942	0.86	0.987	0.987	1	−0.931	−0.948	0.987	0.948
color_coordinate_x	−0.99	0.998	−0.963	−0.921	−0.923	−0.931	1	0.981	−0.923	− 0.991
color_coordinate_y	−0.996	0.982	−0.896	−0.914	−0.916	−0.948	0.981	1	−0.916	− 0.992
Illuminance	0.931	−0.933	0.886	1	1	0.987	−0.923	−0.916	1	0.922
CCT (color temperature)	0.997	−0.993	0.928	0.92	0.922	0.948	−0.991	−0.992	0.922	1