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B. M. J. K. Balasooriya et al.
Table 5.2
Classification functions resulting from discriminant analysis applied to the clusters of groundwater wells in Sri Lanka
Variables
Standard mode F
= 110.62
Forward mode F
= 142.52
Backward mode F
= 196.90
p
< 0.000
p
< 0.000
p
< 0.000
Cluster 1
Cluster 2
p
value
Cluster 1
Cluster 2
p
value
Cluster 1
Cluster 2
p
value
Fluoride
1.045
−0.339
0.000
1.045
−0.339
0.000
1.081
−0.351
0.000
EC
1.424
−0.462
0.003
1.431
−0.466
0.002
1.175
−0.418
0.000
pH
−0.294
0.073
0.017
−0.300
0.076
0.011
–
–
–
Chloride
−0.543
0.155
0.018
−0.546
0.158
0.017
–
–
–
Sulphate
−0.752
0.229
0.000
-0.756
0.231
0.000
−0.597
0.186
0.000
Nitrate
0.537
−0.174
0.000
0.536
-0.174
0.000
0.571
−0.181
0.000
Sodium
1.085
−0.314
0.001
1.086
−0.315
0.001
0.749
−0.203
0.001
Magnesium
1.534
−0.447
0.000
1.533
−0.447
0.000
1.529
−0.444
0.000
Calcium
0.261
−0.084
0.142
0.265
−0.085
0.136
–
–
–
Aluminium
0.002
−0.005
0.964
–
–
–
–
–
–
Chromium
0.424
-0.121
0.000
0.424
−0.120
0.000
0.393
−0.113
0.000
Ferrous
−0.044
0.018
0.654
–
–
–
–
–
–
Nickel
−0.322
0.099
0.000
−0.327
0.100
0.000
−0.367
0.113
0.000
Copper
−0.068
0.017
0.460
–
–
–
–
–
–
Zinc
−0.137
0.043
0.135
−0.158
0.048
0.069
–
–
–
Arsenic
0.603
−0.182
0.000
0.601
−0.181
0.000
0.590
−0.179
0.000
Cadmium
0.585
−0.177
0.000
0.577
−0.175
0.000
0.580
−0.175
0.000
Lead
0.013
−0.005
0.868
–
–
–
–
–
–
(Constant)
−4.015
−0.519
–
−4.012
−0.519
–
−3.968
−0.515
–