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. Author manuscript; available in PMC: 2015 Mar 11.
Published in final edited form as: Chronobiol Int. 2014 Oct 7;32(2):270–280. doi: 10.3109/07420528.2014.966269

TABLE 1.

Regression coefficients, standard errors (se) and p Values for the modeling using Actiwatch spectral R, G, B outputs to predict photoreceptor excitations under daylight illuminants or fluorescent illuminants.

Photoreceptor β(RW) se p Value β(GW) se p Value β(BW) se p Value R2 Mean error
Daylight illuminants
 Our Actiwatch S-cone 1.707 0.124 <0.001 −9.126 0.351 <0.001 27.947 0.288 <0.001 1.000 0.0022
L-cone 1.732 0.003 <0.001 5.789 0.010 <0.001 0.249 0.008 <0.001 1.000 0.0001
Rod 0.962 0.049 <0.001 4.114 0.138 <0.001 10.822 0.114 <0.001 1.000 0.0008
ipRGC 0.930 0.066 <0.001 1.563 0.189 <0.001 14.692 0.155 <0.001 1.000 0.0011
 Price et al.’s Typical Actiwatch S-cone 2.364 0.191 <0.001 −12.029 0.501 <0.001 33.148 0.483 <0.001 1.000 0.0031
L-cone 1.738 0.009 <0.001 5.890 0.025 <0.001 0.022 0.024 0.359 0.999 0.0001
Rod 1.160 0.067 <0.001 2.815 0.176 <0.001 12.616 0.170 <0.001 1.000 0.0010
ipRGC 1.221 0.095 <0.001 −0.147 0.250 0.563 17.258 0.241 <0.001 1.000 0.0014
Fluorescent illuminants
 Our Actiwatch S-cone −0.133 0.064 0.837 −2.930 2.223 0.200 20.465 2.875 <0.001 0.873 0.0437
L-cone 1.676 0.064 <0.001 6.496 0.223 <0.001 −0.555 0.289 0.066 0.796 0.0040
Rod 0.983 0.870 0.270 −0.294 3.036 0.924 15.051 3.925 0.001 0.611 0.0607
ipRGC 0.902 1.036 0.393 −3.344 3.614 0.364 19.242 4.673 <0.001 0.630 0.0649
 Price et al.’s Typical Actiwatch S-cone −1.044 0.965 0.290 −1.350 3.928 0.734 18.616 5.372 0.002 0.800 0.0545
L-cone 1.858 0.099 <0.001 5.924 0.405 <0.001 0.084 0.554 0.881 0.664 0.0053
Rod −1.071 1.180 0.373 7.497 4.804 0.132 4.701 6.570 0.481 0.508 0.0607
ipRGC −1.662 1.445 0.261 6.271 5.882 0.297 6.596 8.046 0.420 0.504 0.0845

R2 is calculated by the square of the correlation between the observed and predicted values, a conservative statistic for describing the fitting quality of regression through the origin model. The error is computed by |log (Ŷ/Y)|, where Y and Ŷ are observed and predicted values, respectively.