deltatensor: Creates a Kronecker delta tensor

Description Usage Arguments Details Value Author(s) See Also Examples

Description

The delta tensor is the tensor equivalent of the identity.

Usage

1

Arguments

d

the row dimensions

mark

a character to be concatenated to the names of the row dimensions to get the column dimension names

dn

dimnames for the result

by

the dimensions which should not be duplicated

Details

E_{i_1...i_n j_1...j_n}=δ_{i_1j_1}...δ_{i_n j_n}

Value

a tensor with dimension c(d,mark(d,mark))

Author(s)

K. Gerald van den Boogaart

See Also

to.tensor

Examples

1
delta.tensor(c(a=2,b=3))

Example output

Attaching package:tensorAThe following object is masked frompackage:base:

    norm

, , 1, 1

      b
a      [,1] [,2] [,3]
  [1,]    1    0    0
  [2,]    0    0    0

, , 2, 1

      b
a      [,1] [,2] [,3]
  [1,]    0    0    0
  [2,]    1    0    0

, , 1, 2

      b
a      [,1] [,2] [,3]
  [1,]    0    1    0
  [2,]    0    0    0

, , 2, 2

      b
a      [,1] [,2] [,3]
  [1,]    0    0    0
  [2,]    0    1    0

, , 1, 3

      b
a      [,1] [,2] [,3]
  [1,]    0    0    1
  [2,]    0    0    0

, , 2, 3

      b
a      [,1] [,2] [,3]
  [1,]    0    0    0
  [2,]    0    0    1

attr(,"class")
[1] "tensor"

tensorA documentation built on Nov. 20, 2020, 9:07 a.m.

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