Table 1:
Various kernels and their induced covariance functions in the two-dimensional plane.
Kernel
Covariance function
K
(
t
)
α
Exp
(
−
1
/
2
‖
t
‖
2
)
C
(
d
)
α
Exp
(
−
1
/
2
‖
d
/
2
‖
2
)
K
(
t
)
α
I
[
‖
t
‖
<
1
/
2
]
C
(
d
)
α
Exp
(
−
‖
d
‖
)
K
(
t
)
α
(
1
−
‖
t
‖
3
/
s
3
)
3
I
[
t
<
s
]
C
(
d
)
α
(
1
−
3
/
2
‖
d
‖
+
1
/
2
‖
d
‖
3
)
I
[
d
<
1
]