. 2017 Jan 4;5:e2838. doi: 10.7717/peerj.2838

Table 2. Model performance statistics.

Measurement type	Parameter	Concentration (mg-N L⁻¹)				Mean bias (mg-N L⁻¹)	Mean error (mg-N L⁻¹)	NMB	NME	R²	RMSE
		Observed		Simulated
		Mean	SD	Mean	SD
7-d model calibration
Sensor	Food	0.07	0.03	0.07	0.04	0.004	0.013	5.2%	20%	0.81	0.018
	NH $_{4}^{+}$	0.09	0.01	0.09	0.01	−0.001	0.005	−1.3%	6%	0.33	0.006
	NO $_{3}^{-}$	0.62	0.11	0.62	0.10	0.0001	0.024	0.02%	4%	0.94	0.030
Discrete sample	Food	0.07	0.03	0.07	0.03	−0.007	0.037	−9.9%	51%	0.01	0.045
	NH $_{4}^{+}$	0.09	0.02	0.09	0.01	−0.002	0.012	−2.4%	13%	0.10	0.015
	NO $_{3}^{-}$	0.61	0.14	0.61	0.11	0.004	0.034	0.6%	6%	0.91	0.048
	Org N	0.49	0.13	0.49	0.15	0.002	0.118	0.3%	24%	0.19	0.142
	NO $_{2}^{-}$	0.05	0.01	0.04	0.01	−0.002	0.006	−5.2%	12%	0.37	0.006
	Total N	1.2	0.18	1.2	0.19	−0.00004	0.111	−0.003%	9%	0.54	0.133
10-d model evaluation
Sensor	Food^a	0.08	0.03	0.08	0.03	−0.013	0.013	−17.1%	17.1%	0.85	0.016
	NH $_{4}^{+}$	0.03	0.002	0.03	0.002	0.0003	0.001	1.0%	7.7%	0.35	0.001
	NO $_{3}^{-}$	3.5	1.8	3.0	1.3	−0.513	0.549	−14.5%	15.5%	0.93	0.817
Discrete sample	Food	0.03	0.02	0.09	0.04	0.064	0.065	250%	260%	0.51	0.080
	NH $_{4}^{+}$	0.04	0.01	0.03	0.002	−0.004	0.011	−11%	28%	0.06	0.014
	NO $_{3}^{-}$	4.3	2.5	3.5	1.5	−0.874	0.938	−20%	22%	0.98	1.391
	Org N	0.79	0.14	0.77	0.24	−0.027	0.090	−3.4%	11%	0.78	0.121
	NO $_{2}^{-}$	0.03	0.01	0.03	0.005	0.001	0.006	3.1%	19%	0.62	0.006
	Total N	5.2	2.5	4.3	1.5	−0.903	0.954	−17%	18%	0.96	1.296

Notes.

25 day moving average.