Geology Reference
In-Depth Information
P
i¼1
ð
Q
o
Q
o
Þ
P
i¼1
ð
Q
m
Q
m
Þ
Q
m
Q
m
Þ
:
ð
Correlation Coefficient
;
CORR ¼
q
ð
5
:
1
Þ
2
2
:
ð
Q
o
Q
o
Þ
N
X
N
1
ð
Q
m
Q
o
Þ
Mean Absolute Percentage Error, MAPE
¼
100
ð
5
:
2
Þ
Q
o
i¼1
E
1
E
2
E
1
Efficiency
E
¼
ð
5
:
3
Þ
;
where
X
N
2
Q
o
Q
o
ð
Þ
ð
5
:
4
Þ
E
1
¼
i¼1
and
X
N
2
E
2
¼
ð
Q
0
Q
m
Þ
ð
5
:
5
Þ
i¼1
t
1
N
X
N
i¼1
ð
2
¼
Q
m
Q
o
Þ
ð
5
:
6
Þ
Root Mean Squared Error, RMSE
P
i¼1
ð
Q
o
Q
m
Þ
Mean bias error, MBE
¼
ð
5
:
7
Þ
N
Variance of the distribution of differences S
2
which expresses the variability of
(Q
o
−
Q
m
) distribution about MBE
P
i¼1
ð
2
Q
o
Q
m
MBE
Þ
S
d
¼
ð
5
:
8
Þ
N
1
where, Q
m
is the modelled or e
st
imated solar radiation by a data based model, Q
o
i
s
the observation solar radiation Q
m
is the average of the estimated solar radiation, Q
o
is the average of the observed r radiation and N is the number of observations.
