Multiplies tensors by multiplying over all duplicate names according to Einsteins summing convention by doing an implicit inner product over all dimensions with the same name.

einstein.tensor(...,only=NULL,by=NULL)
## Methods for class tensor
# x %e% y
## Default method
# x %e% y

Arguments

...

some tensors, or a renaming code

only

optional list, if given only names in this list are automatically processed

x

a tensor

y

a tensor

by

the parallel dimensions

Value

the tensor product of all the tensors along all duplicate dimensions.

Details

see mul.tensor on details on tensor multiplication. In einstein.tensor complex operations can be performed by command and renaming code: The arguments are processed from left to right and multiplied. Unnamed attributes are regarded as tensors or scalars and multiplied with the current result by the Einstein summing convention, which means an inner product over all dimensions with the same name. Named attributes can either have the name diag, which performs a diagmul according to the same-name convention or be of the form A="B" or "A"="B", for which we have two cases. If both names are present in the current result, an inner multiplication (trace) of on these two dimensions is performed. If only the first is a name up to this point, the specific dimension is renamed to the second name. This renaming might be visible in the result or inducing a multiplication according to the Einstein convention later.

Author

K. Gerald van den Boogaart

Examples

A <- to.tensor(1:20,c(U=2,V=2,W=5))
B <- to.tensor(1:30,list(U=c("a","b","c"),V=c("B1","B2"),W=1:5))
einstein.tensor(A,U="U'",B)
#>       U
#> U'        a    b    c
#>   [1,] 1945 2045 2145
#>   [2,] 2090 2200 2310
#> attr(,"class")
#> [1] "tensor" "matrix"
einstein.tensor(A,U="U'",mark(B,"k"))
#> , , 1, Uk = a, Vk = B1, Wk = 1
#> 
#>       V
#> U'     [,1] [,2]
#>   [1,]    1    3
#>   [2,]    2    4
#> 
#> , , 2, Uk = a, Vk = B1, Wk = 1
#> 
#>       V
#> U'     [,1] [,2]
#>   [1,]    5    7
#>   [2,]    6    8
#> 
#> , , 3, Uk = a, Vk = B1, Wk = 1
#> 
#>       V
#> U'     [,1] [,2]
#>   [1,]    9   11
#>   [2,]   10   12
#> 
#> , , 4, Uk = a, Vk = B1, Wk = 1
#> 
#>       V
#> U'     [,1] [,2]
#>   [1,]   13   15
#>   [2,]   14   16
#> 
#> , , 5, Uk = a, Vk = B1, Wk = 1
#> 
#>       V
#> U'     [,1] [,2]
#>   [1,]   17   19
#>   [2,]   18   20
#> 
#> , , 1, Uk = b, Vk = B1, Wk = 1
#> 
#>       V
#> U'     [,1] [,2]
#>   [1,]    2    6
#>   [2,]    4    8
#> 
#> , , 2, Uk = b, Vk = B1, Wk = 1
#> 
#>       V
#> U'     [,1] [,2]
#>   [1,]   10   14
#>   [2,]   12   16
#> 
#> , , 3, Uk = b, Vk = B1, Wk = 1
#> 
#>       V
#> U'     [,1] [,2]
#>   [1,]   18   22
#>   [2,]   20   24
#> 
#> , , 4, Uk = b, Vk = B1, Wk = 1
#> 
#>       V
#> U'     [,1] [,2]
#>   [1,]   26   30
#>   [2,]   28   32
#> 
#> , , 5, Uk = b, Vk = B1, Wk = 1
#> 
#>       V
#> U'     [,1] [,2]
#>   [1,]   34   38
#>   [2,]   36   40
#> 
#> , , 1, Uk = c, Vk = B1, Wk = 1
#> 
#>       V
#> U'     [,1] [,2]
#>   [1,]    3    9
#>   [2,]    6   12
#> 
#> , , 2, Uk = c, Vk = B1, Wk = 1
#> 
#>       V
#> U'     [,1] [,2]
#>   [1,]   15   21
#>   [2,]   18   24
#> 
#> , , 3, Uk = c, Vk = B1, Wk = 1
#> 
#>       V
#> U'     [,1] [,2]
#>   [1,]   27   33
#>   [2,]   30   36
#> 
#> , , 4, Uk = c, Vk = B1, Wk = 1
#> 
#>       V
#> U'     [,1] [,2]
#>   [1,]   39   45
#>   [2,]   42   48
#> 
#> , , 5, Uk = c, Vk = B1, Wk = 1
#> 
#>       V
#> U'     [,1] [,2]
#>   [1,]   51   57
#>   [2,]   54   60
#> 
#> , , 1, Uk = a, Vk = B2, Wk = 1
#> 
#>       V
#> U'     [,1] [,2]
#>   [1,]    4   12
#>   [2,]    8   16
#> 
#> , , 2, Uk = a, Vk = B2, Wk = 1
#> 
#>       V
#> U'     [,1] [,2]
#>   [1,]   20   28
#>   [2,]   24   32
#> 
#> , , 3, Uk = a, Vk = B2, Wk = 1
#> 
#>       V
#> U'     [,1] [,2]
#>   [1,]   36   44
#>   [2,]   40   48
#> 
#> , , 4, Uk = a, Vk = B2, Wk = 1
#> 
#>       V
#> U'     [,1] [,2]
#>   [1,]   52   60
#>   [2,]   56   64
#> 
#> , , 5, Uk = a, Vk = B2, Wk = 1
#> 
#>       V
#> U'     [,1] [,2]
#>   [1,]   68   76
#>   [2,]   72   80
#> 
#> , , 1, Uk = b, Vk = B2, Wk = 1
#> 
#>       V
#> U'     [,1] [,2]
#>   [1,]    5   15
#>   [2,]   10   20
#> 
#> , , 2, Uk = b, Vk = B2, Wk = 1
#> 
#>       V
#> U'     [,1] [,2]
#>   [1,]   25   35
#>   [2,]   30   40
#> 
#> , , 3, Uk = b, Vk = B2, Wk = 1
#> 
#>       V
#> U'     [,1] [,2]
#>   [1,]   45   55
#>   [2,]   50   60
#> 
#> , , 4, Uk = b, Vk = B2, Wk = 1
#> 
#>       V
#> U'     [,1] [,2]
#>   [1,]   65   75
#>   [2,]   70   80
#> 
#> , , 5, Uk = b, Vk = B2, Wk = 1
#> 
#>       V
#> U'     [,1] [,2]
#>   [1,]   85   95
#>   [2,]   90  100
#> 
#> , , 1, Uk = c, Vk = B2, Wk = 1
#> 
#>       V
#> U'     [,1] [,2]
#>   [1,]    6   18
#>   [2,]   12   24
#> 
#> , , 2, Uk = c, Vk = B2, Wk = 1
#> 
#>       V
#> U'     [,1] [,2]
#>   [1,]   30   42
#>   [2,]   36   48
#> 
#> , , 3, Uk = c, Vk = B2, Wk = 1
#> 
#>       V
#> U'     [,1] [,2]
#>   [1,]   54   66
#>   [2,]   60   72
#> 
#> , , 4, Uk = c, Vk = B2, Wk = 1
#> 
#>       V
#> U'     [,1] [,2]
#>   [1,]   78   90
#>   [2,]   84   96
#> 
#> , , 5, Uk = c, Vk = B2, Wk = 1
#> 
#>       V
#> U'     [,1] [,2]
#>   [1,]  102  114
#>   [2,]  108  120
#> 
#> , , 1, Uk = a, Vk = B1, Wk = 2
#> 
#>       V
#> U'     [,1] [,2]
#>   [1,]    7   21
#>   [2,]   14   28
#> 
#> , , 2, Uk = a, Vk = B1, Wk = 2
#> 
#>       V
#> U'     [,1] [,2]
#>   [1,]   35   49
#>   [2,]   42   56
#> 
#> , , 3, Uk = a, Vk = B1, Wk = 2
#> 
#>       V
#> U'     [,1] [,2]
#>   [1,]   63   77
#>   [2,]   70   84
#> 
#> , , 4, Uk = a, Vk = B1, Wk = 2
#> 
#>       V
#> U'     [,1] [,2]
#>   [1,]   91  105
#>   [2,]   98  112
#> 
#> , , 5, Uk = a, Vk = B1, Wk = 2
#> 
#>       V
#> U'     [,1] [,2]
#>   [1,]  119  133
#>   [2,]  126  140
#> 
#> , , 1, Uk = b, Vk = B1, Wk = 2
#> 
#>       V
#> U'     [,1] [,2]
#>   [1,]    8   24
#>   [2,]   16   32
#> 
#> , , 2, Uk = b, Vk = B1, Wk = 2
#> 
#>       V
#> U'     [,1] [,2]
#>   [1,]   40   56
#>   [2,]   48   64
#> 
#> , , 3, Uk = b, Vk = B1, Wk = 2
#> 
#>       V
#> U'     [,1] [,2]
#>   [1,]   72   88
#>   [2,]   80   96
#> 
#> , , 4, Uk = b, Vk = B1, Wk = 2
#> 
#>       V
#> U'     [,1] [,2]
#>   [1,]  104  120
#>   [2,]  112  128
#> 
#> , , 5, Uk = b, Vk = B1, Wk = 2
#> 
#>       V
#> U'     [,1] [,2]
#>   [1,]  136  152
#>   [2,]  144  160
#> 
#> , , 1, Uk = c, Vk = B1, Wk = 2
#> 
#>       V
#> U'     [,1] [,2]
#>   [1,]    9   27
#>   [2,]   18   36
#> 
#> , , 2, Uk = c, Vk = B1, Wk = 2
#> 
#>       V
#> U'     [,1] [,2]
#>   [1,]   45   63
#>   [2,]   54   72
#> 
#> , , 3, Uk = c, Vk = B1, Wk = 2
#> 
#>       V
#> U'     [,1] [,2]
#>   [1,]   81   99
#>   [2,]   90  108
#> 
#> , , 4, Uk = c, Vk = B1, Wk = 2
#> 
#>       V
#> U'     [,1] [,2]
#>   [1,]  117  135
#>   [2,]  126  144
#> 
#> , , 5, Uk = c, Vk = B1, Wk = 2
#> 
#>       V
#> U'     [,1] [,2]
#>   [1,]  153  171
#>   [2,]  162  180
#> 
#> , , 1, Uk = a, Vk = B2, Wk = 2
#> 
#>       V
#> U'     [,1] [,2]
#>   [1,]   10   30
#>   [2,]   20   40
#> 
#> , , 2, Uk = a, Vk = B2, Wk = 2
#> 
#>       V
#> U'     [,1] [,2]
#>   [1,]   50   70
#>   [2,]   60   80
#> 
#> , , 3, Uk = a, Vk = B2, Wk = 2
#> 
#>       V
#> U'     [,1] [,2]
#>   [1,]   90  110
#>   [2,]  100  120
#> 
#> , , 4, Uk = a, Vk = B2, Wk = 2
#> 
#>       V
#> U'     [,1] [,2]
#>   [1,]  130  150
#>   [2,]  140  160
#> 
#> , , 5, Uk = a, Vk = B2, Wk = 2
#> 
#>       V
#> U'     [,1] [,2]
#>   [1,]  170  190
#>   [2,]  180  200
#> 
#> , , 1, Uk = b, Vk = B2, Wk = 2
#> 
#>       V
#> U'     [,1] [,2]
#>   [1,]   11   33
#>   [2,]   22   44
#> 
#> , , 2, Uk = b, Vk = B2, Wk = 2
#> 
#>       V
#> U'     [,1] [,2]
#>   [1,]   55   77
#>   [2,]   66   88
#> 
#> , , 3, Uk = b, Vk = B2, Wk = 2
#> 
#>       V
#> U'     [,1] [,2]
#>   [1,]   99  121
#>   [2,]  110  132
#> 
#> , , 4, Uk = b, Vk = B2, Wk = 2
#> 
#>       V
#> U'     [,1] [,2]
#>   [1,]  143  165
#>   [2,]  154  176
#> 
#> , , 5, Uk = b, Vk = B2, Wk = 2
#> 
#>       V
#> U'     [,1] [,2]
#>   [1,]  187  209
#>   [2,]  198  220
#> 
#> , , 1, Uk = c, Vk = B2, Wk = 2
#> 
#>       V
#> U'     [,1] [,2]
#>   [1,]   12   36
#>   [2,]   24   48
#> 
#> , , 2, Uk = c, Vk = B2, Wk = 2
#> 
#>       V
#> U'     [,1] [,2]
#>   [1,]   60   84
#>   [2,]   72   96
#> 
#> , , 3, Uk = c, Vk = B2, Wk = 2
#> 
#>       V
#> U'     [,1] [,2]
#>   [1,]  108  132
#>   [2,]  120  144
#> 
#> , , 4, Uk = c, Vk = B2, Wk = 2
#> 
#>       V
#> U'     [,1] [,2]
#>   [1,]  156  180
#>   [2,]  168  192
#> 
#> , , 5, Uk = c, Vk = B2, Wk = 2
#> 
#>       V
#> U'     [,1] [,2]
#>   [1,]  204  228
#>   [2,]  216  240
#> 
#> , , 1, Uk = a, Vk = B1, Wk = 3
#> 
#>       V
#> U'     [,1] [,2]
#>   [1,]   13   39
#>   [2,]   26   52
#> 
#> , , 2, Uk = a, Vk = B1, Wk = 3
#> 
#>       V
#> U'     [,1] [,2]
#>   [1,]   65   91
#>   [2,]   78  104
#> 
#> , , 3, Uk = a, Vk = B1, Wk = 3
#> 
#>       V
#> U'     [,1] [,2]
#>   [1,]  117  143
#>   [2,]  130  156
#> 
#> , , 4, Uk = a, Vk = B1, Wk = 3
#> 
#>       V
#> U'     [,1] [,2]
#>   [1,]  169  195
#>   [2,]  182  208
#> 
#> , , 5, Uk = a, Vk = B1, Wk = 3
#> 
#>       V
#> U'     [,1] [,2]
#>   [1,]  221  247
#>   [2,]  234  260
#> 
#> , , 1, Uk = b, Vk = B1, Wk = 3
#> 
#>       V
#> U'     [,1] [,2]
#>   [1,]   14   42
#>   [2,]   28   56
#> 
#> , , 2, Uk = b, Vk = B1, Wk = 3
#> 
#>       V
#> U'     [,1] [,2]
#>   [1,]   70   98
#>   [2,]   84  112
#> 
#> , , 3, Uk = b, Vk = B1, Wk = 3
#> 
#>       V
#> U'     [,1] [,2]
#>   [1,]  126  154
#>   [2,]  140  168
#> 
#> , , 4, Uk = b, Vk = B1, Wk = 3
#> 
#>       V
#> U'     [,1] [,2]
#>   [1,]  182  210
#>   [2,]  196  224
#> 
#> , , 5, Uk = b, Vk = B1, Wk = 3
#> 
#>       V
#> U'     [,1] [,2]
#>   [1,]  238  266
#>   [2,]  252  280
#> 
#> , , 1, Uk = c, Vk = B1, Wk = 3
#> 
#>       V
#> U'     [,1] [,2]
#>   [1,]   15   45
#>   [2,]   30   60
#> 
#> , , 2, Uk = c, Vk = B1, Wk = 3
#> 
#>       V
#> U'     [,1] [,2]
#>   [1,]   75  105
#>   [2,]   90  120
#> 
#> , , 3, Uk = c, Vk = B1, Wk = 3
#> 
#>       V
#> U'     [,1] [,2]
#>   [1,]  135  165
#>   [2,]  150  180
#> 
#> , , 4, Uk = c, Vk = B1, Wk = 3
#> 
#>       V
#> U'     [,1] [,2]
#>   [1,]  195  225
#>   [2,]  210  240
#> 
#> , , 5, Uk = c, Vk = B1, Wk = 3
#> 
#>       V
#> U'     [,1] [,2]
#>   [1,]  255  285
#>   [2,]  270  300
#> 
#> , , 1, Uk = a, Vk = B2, Wk = 3
#> 
#>       V
#> U'     [,1] [,2]
#>   [1,]   16   48
#>   [2,]   32   64
#> 
#> , , 2, Uk = a, Vk = B2, Wk = 3
#> 
#>       V
#> U'     [,1] [,2]
#>   [1,]   80  112
#>   [2,]   96  128
#> 
#> , , 3, Uk = a, Vk = B2, Wk = 3
#> 
#>       V
#> U'     [,1] [,2]
#>   [1,]  144  176
#>   [2,]  160  192
#> 
#> , , 4, Uk = a, Vk = B2, Wk = 3
#> 
#>       V
#> U'     [,1] [,2]
#>   [1,]  208  240
#>   [2,]  224  256
#> 
#> , , 5, Uk = a, Vk = B2, Wk = 3
#> 
#>       V
#> U'     [,1] [,2]
#>   [1,]  272  304
#>   [2,]  288  320
#> 
#> , , 1, Uk = b, Vk = B2, Wk = 3
#> 
#>       V
#> U'     [,1] [,2]
#>   [1,]   17   51
#>   [2,]   34   68
#> 
#> , , 2, Uk = b, Vk = B2, Wk = 3
#> 
#>       V
#> U'     [,1] [,2]
#>   [1,]   85  119
#>   [2,]  102  136
#> 
#> , , 3, Uk = b, Vk = B2, Wk = 3
#> 
#>       V
#> U'     [,1] [,2]
#>   [1,]  153  187
#>   [2,]  170  204
#> 
#> , , 4, Uk = b, Vk = B2, Wk = 3
#> 
#>       V
#> U'     [,1] [,2]
#>   [1,]  221  255
#>   [2,]  238  272
#> 
#> , , 5, Uk = b, Vk = B2, Wk = 3
#> 
#>       V
#> U'     [,1] [,2]
#>   [1,]  289  323
#>   [2,]  306  340
#> 
#> , , 1, Uk = c, Vk = B2, Wk = 3
#> 
#>       V
#> U'     [,1] [,2]
#>   [1,]   18   54
#>   [2,]   36   72
#> 
#> , , 2, Uk = c, Vk = B2, Wk = 3
#> 
#>       V
#> U'     [,1] [,2]
#>   [1,]   90  126
#>   [2,]  108  144
#> 
#> , , 3, Uk = c, Vk = B2, Wk = 3
#> 
#>       V
#> U'     [,1] [,2]
#>   [1,]  162  198
#>   [2,]  180  216
#> 
#> , , 4, Uk = c, Vk = B2, Wk = 3
#> 
#>       V
#> U'     [,1] [,2]
#>   [1,]  234  270
#>   [2,]  252  288
#> 
#> , , 5, Uk = c, Vk = B2, Wk = 3
#> 
#>       V
#> U'     [,1] [,2]
#>   [1,]  306  342
#>   [2,]  324  360
#> 
#> , , 1, Uk = a, Vk = B1, Wk = 4
#> 
#>       V
#> U'     [,1] [,2]
#>   [1,]   19   57
#>   [2,]   38   76
#> 
#> , , 2, Uk = a, Vk = B1, Wk = 4
#> 
#>       V
#> U'     [,1] [,2]
#>   [1,]   95  133
#>   [2,]  114  152
#> 
#> , , 3, Uk = a, Vk = B1, Wk = 4
#> 
#>       V
#> U'     [,1] [,2]
#>   [1,]  171  209
#>   [2,]  190  228
#> 
#> , , 4, Uk = a, Vk = B1, Wk = 4
#> 
#>       V
#> U'     [,1] [,2]
#>   [1,]  247  285
#>   [2,]  266  304
#> 
#> , , 5, Uk = a, Vk = B1, Wk = 4
#> 
#>       V
#> U'     [,1] [,2]
#>   [1,]  323  361
#>   [2,]  342  380
#> 
#> , , 1, Uk = b, Vk = B1, Wk = 4
#> 
#>       V
#> U'     [,1] [,2]
#>   [1,]   20   60
#>   [2,]   40   80
#> 
#> , , 2, Uk = b, Vk = B1, Wk = 4
#> 
#>       V
#> U'     [,1] [,2]
#>   [1,]  100  140
#>   [2,]  120  160
#> 
#> , , 3, Uk = b, Vk = B1, Wk = 4
#> 
#>       V
#> U'     [,1] [,2]
#>   [1,]  180  220
#>   [2,]  200  240
#> 
#> , , 4, Uk = b, Vk = B1, Wk = 4
#> 
#>       V
#> U'     [,1] [,2]
#>   [1,]  260  300
#>   [2,]  280  320
#> 
#> , , 5, Uk = b, Vk = B1, Wk = 4
#> 
#>       V
#> U'     [,1] [,2]
#>   [1,]  340  380
#>   [2,]  360  400
#> 
#> , , 1, Uk = c, Vk = B1, Wk = 4
#> 
#>       V
#> U'     [,1] [,2]
#>   [1,]   21   63
#>   [2,]   42   84
#> 
#> , , 2, Uk = c, Vk = B1, Wk = 4
#> 
#>       V
#> U'     [,1] [,2]
#>   [1,]  105  147
#>   [2,]  126  168
#> 
#> , , 3, Uk = c, Vk = B1, Wk = 4
#> 
#>       V
#> U'     [,1] [,2]
#>   [1,]  189  231
#>   [2,]  210  252
#> 
#> , , 4, Uk = c, Vk = B1, Wk = 4
#> 
#>       V
#> U'     [,1] [,2]
#>   [1,]  273  315
#>   [2,]  294  336
#> 
#> , , 5, Uk = c, Vk = B1, Wk = 4
#> 
#>       V
#> U'     [,1] [,2]
#>   [1,]  357  399
#>   [2,]  378  420
#> 
#> , , 1, Uk = a, Vk = B2, Wk = 4
#> 
#>       V
#> U'     [,1] [,2]
#>   [1,]   22   66
#>   [2,]   44   88
#> 
#> , , 2, Uk = a, Vk = B2, Wk = 4
#> 
#>       V
#> U'     [,1] [,2]
#>   [1,]  110  154
#>   [2,]  132  176
#> 
#> , , 3, Uk = a, Vk = B2, Wk = 4
#> 
#>       V
#> U'     [,1] [,2]
#>   [1,]  198  242
#>   [2,]  220  264
#> 
#> , , 4, Uk = a, Vk = B2, Wk = 4
#> 
#>       V
#> U'     [,1] [,2]
#>   [1,]  286  330
#>   [2,]  308  352
#> 
#> , , 5, Uk = a, Vk = B2, Wk = 4
#> 
#>       V
#> U'     [,1] [,2]
#>   [1,]  374  418
#>   [2,]  396  440
#> 
#> , , 1, Uk = b, Vk = B2, Wk = 4
#> 
#>       V
#> U'     [,1] [,2]
#>   [1,]   23   69
#>   [2,]   46   92
#> 
#> , , 2, Uk = b, Vk = B2, Wk = 4
#> 
#>       V
#> U'     [,1] [,2]
#>   [1,]  115  161
#>   [2,]  138  184
#> 
#> , , 3, Uk = b, Vk = B2, Wk = 4
#> 
#>       V
#> U'     [,1] [,2]
#>   [1,]  207  253
#>   [2,]  230  276
#> 
#> , , 4, Uk = b, Vk = B2, Wk = 4
#> 
#>       V
#> U'     [,1] [,2]
#>   [1,]  299  345
#>   [2,]  322  368
#> 
#> , , 5, Uk = b, Vk = B2, Wk = 4
#> 
#>       V
#> U'     [,1] [,2]
#>   [1,]  391  437
#>   [2,]  414  460
#> 
#> , , 1, Uk = c, Vk = B2, Wk = 4
#> 
#>       V
#> U'     [,1] [,2]
#>   [1,]   24   72
#>   [2,]   48   96
#> 
#> , , 2, Uk = c, Vk = B2, Wk = 4
#> 
#>       V
#> U'     [,1] [,2]
#>   [1,]  120  168
#>   [2,]  144  192
#> 
#> , , 3, Uk = c, Vk = B2, Wk = 4
#> 
#>       V
#> U'     [,1] [,2]
#>   [1,]  216  264
#>   [2,]  240  288
#> 
#> , , 4, Uk = c, Vk = B2, Wk = 4
#> 
#>       V
#> U'     [,1] [,2]
#>   [1,]  312  360
#>   [2,]  336  384
#> 
#> , , 5, Uk = c, Vk = B2, Wk = 4
#> 
#>       V
#> U'     [,1] [,2]
#>   [1,]  408  456
#>   [2,]  432  480
#> 
#> , , 1, Uk = a, Vk = B1, Wk = 5
#> 
#>       V
#> U'     [,1] [,2]
#>   [1,]   25   75
#>   [2,]   50  100
#> 
#> , , 2, Uk = a, Vk = B1, Wk = 5
#> 
#>       V
#> U'     [,1] [,2]
#>   [1,]  125  175
#>   [2,]  150  200
#> 
#> , , 3, Uk = a, Vk = B1, Wk = 5
#> 
#>       V
#> U'     [,1] [,2]
#>   [1,]  225  275
#>   [2,]  250  300
#> 
#> , , 4, Uk = a, Vk = B1, Wk = 5
#> 
#>       V
#> U'     [,1] [,2]
#>   [1,]  325  375
#>   [2,]  350  400
#> 
#> , , 5, Uk = a, Vk = B1, Wk = 5
#> 
#>       V
#> U'     [,1] [,2]
#>   [1,]  425  475
#>   [2,]  450  500
#> 
#> , , 1, Uk = b, Vk = B1, Wk = 5
#> 
#>       V
#> U'     [,1] [,2]
#>   [1,]   26   78
#>   [2,]   52  104
#> 
#> , , 2, Uk = b, Vk = B1, Wk = 5
#> 
#>       V
#> U'     [,1] [,2]
#>   [1,]  130  182
#>   [2,]  156  208
#> 
#> , , 3, Uk = b, Vk = B1, Wk = 5
#> 
#>       V
#> U'     [,1] [,2]
#>   [1,]  234  286
#>   [2,]  260  312
#> 
#> , , 4, Uk = b, Vk = B1, Wk = 5
#> 
#>       V
#> U'     [,1] [,2]
#>   [1,]  338  390
#>   [2,]  364  416
#> 
#> , , 5, Uk = b, Vk = B1, Wk = 5
#> 
#>       V
#> U'     [,1] [,2]
#>   [1,]  442  494
#>   [2,]  468  520
#> 
#> , , 1, Uk = c, Vk = B1, Wk = 5
#> 
#>       V
#> U'     [,1] [,2]
#>   [1,]   27   81
#>   [2,]   54  108
#> 
#> , , 2, Uk = c, Vk = B1, Wk = 5
#> 
#>       V
#> U'     [,1] [,2]
#>   [1,]  135  189
#>   [2,]  162  216
#> 
#> , , 3, Uk = c, Vk = B1, Wk = 5
#> 
#>       V
#> U'     [,1] [,2]
#>   [1,]  243  297
#>   [2,]  270  324
#> 
#> , , 4, Uk = c, Vk = B1, Wk = 5
#> 
#>       V
#> U'     [,1] [,2]
#>   [1,]  351  405
#>   [2,]  378  432
#> 
#> , , 5, Uk = c, Vk = B1, Wk = 5
#> 
#>       V
#> U'     [,1] [,2]
#>   [1,]  459  513
#>   [2,]  486  540
#> 
#> , , 1, Uk = a, Vk = B2, Wk = 5
#> 
#>       V
#> U'     [,1] [,2]
#>   [1,]   28   84
#>   [2,]   56  112
#> 
#> , , 2, Uk = a, Vk = B2, Wk = 5
#> 
#>       V
#> U'     [,1] [,2]
#>   [1,]  140  196
#>   [2,]  168  224
#> 
#> , , 3, Uk = a, Vk = B2, Wk = 5
#> 
#>       V
#> U'     [,1] [,2]
#>   [1,]  252  308
#>   [2,]  280  336
#> 
#> , , 4, Uk = a, Vk = B2, Wk = 5
#> 
#>       V
#> U'     [,1] [,2]
#>   [1,]  364  420
#>   [2,]  392  448
#> 
#> , , 5, Uk = a, Vk = B2, Wk = 5
#> 
#>       V
#> U'     [,1] [,2]
#>   [1,]  476  532
#>   [2,]  504  560
#> 
#> , , 1, Uk = b, Vk = B2, Wk = 5
#> 
#>       V
#> U'     [,1] [,2]
#>   [1,]   29   87
#>   [2,]   58  116
#> 
#> , , 2, Uk = b, Vk = B2, Wk = 5
#> 
#>       V
#> U'     [,1] [,2]
#>   [1,]  145  203
#>   [2,]  174  232
#> 
#> , , 3, Uk = b, Vk = B2, Wk = 5
#> 
#>       V
#> U'     [,1] [,2]
#>   [1,]  261  319
#>   [2,]  290  348
#> 
#> , , 4, Uk = b, Vk = B2, Wk = 5
#> 
#>       V
#> U'     [,1] [,2]
#>   [1,]  377  435
#>   [2,]  406  464
#> 
#> , , 5, Uk = b, Vk = B2, Wk = 5
#> 
#>       V
#> U'     [,1] [,2]
#>   [1,]  493  551
#>   [2,]  522  580
#> 
#> , , 1, Uk = c, Vk = B2, Wk = 5
#> 
#>       V
#> U'     [,1] [,2]
#>   [1,]   30   90
#>   [2,]   60  120
#> 
#> , , 2, Uk = c, Vk = B2, Wk = 5
#> 
#>       V
#> U'     [,1] [,2]
#>   [1,]  150  210
#>   [2,]  180  240
#> 
#> , , 3, Uk = c, Vk = B2, Wk = 5
#> 
#>       V
#> U'     [,1] [,2]
#>   [1,]  270  330
#>   [2,]  300  360
#> 
#> , , 4, Uk = c, Vk = B2, Wk = 5
#> 
#>       V
#> U'     [,1] [,2]
#>   [1,]  390  450
#>   [2,]  420  480
#> 
#> , , 5, Uk = c, Vk = B2, Wk = 5
#> 
#>       V
#> U'     [,1] [,2]
#>   [1,]  510  570
#>   [2,]  540  600
#> 
#> attr(,"class")
#> [1] "tensor"
einstein.tensor(A,U="U'",mark(B,"k"),V="Vk",W="Wk")
#>       Uk
#> U'        a    b    c
#>   [1,] 1945 2045 2145
#>   [2,] 2090 2200 2310
#> attr(,"class")
#> [1] "tensor" "matrix"
einstein.tensor(A,U="U'",mark(B,"k"),V="Vk",W="Wk",1/10)
#>       Uk
#> U'         a     b     c
#>   [1,] 194.5 204.5 214.5
#>   [2,] 209.0 220.0 231.0
#> attr(,"class")
#> [1] "tensor" "matrix"
einstein.tensor(A,U="U'",mark(B,"k"),V="Vk",W="Wk",diag=to.tensor(c(1,1/10,1/100),c(Uk=3)))
#>       Uk
#> U'        a     b     c
#>   [1,] 1945 204.5 21.45
#>   [2,] 2090 220.0 23.10
#> attr(,"class")
#> [1] "tensor" "matrix"

ftable(einstein.tensor(A,U="U'",B))
#>     U    a    b    c
#> U'                  
#> U'1   1945 2045 2145
#> U'2   2090 2200 2310
ftable(einstein.tensor(A,U="U'",mark(B,"k")))
#>                 Wk   1   2   3   4   5
#> U'  V  W  Uk Vk                       
#> U'1 V1 W1 a  B1      1   7  13  19  25
#>              B2      4  10  16  22  28
#>           b  B1      2   8  14  20  26
#>              B2      5  11  17  23  29
#>           c  B1      3   9  15  21  27
#>              B2      6  12  18  24  30
#>        W2 a  B1      5  35  65  95 125
#>              B2     20  50  80 110 140
#>           b  B1     10  40  70 100 130
#>              B2     25  55  85 115 145
#>           c  B1     15  45  75 105 135
#>              B2     30  60  90 120 150
#>        W3 a  B1      9  63 117 171 225
#>              B2     36  90 144 198 252
#>           b  B1     18  72 126 180 234
#>              B2     45  99 153 207 261
#>           c  B1     27  81 135 189 243
#>              B2     54 108 162 216 270
#>        W4 a  B1     13  91 169 247 325
#>              B2     52 130 208 286 364
#>           b  B1     26 104 182 260 338
#>              B2     65 143 221 299 377
#>           c  B1     39 117 195 273 351
#>              B2     78 156 234 312 390
#>        W5 a  B1     17 119 221 323 425
#>              B2     68 170 272 374 476
#>           b  B1     34 136 238 340 442
#>              B2     85 187 289 391 493
#>           c  B1     51 153 255 357 459
#>              B2    102 204 306 408 510
#>     V2 W1 a  B1      3  21  39  57  75
#>              B2     12  30  48  66  84
#>           b  B1      6  24  42  60  78
#>              B2     15  33  51  69  87
#>           c  B1      9  27  45  63  81
#>              B2     18  36  54  72  90
#>        W2 a  B1      7  49  91 133 175
#>              B2     28  70 112 154 196
#>           b  B1     14  56  98 140 182
#>              B2     35  77 119 161 203
#>           c  B1     21  63 105 147 189
#>              B2     42  84 126 168 210
#>        W3 a  B1     11  77 143 209 275
#>              B2     44 110 176 242 308
#>           b  B1     22  88 154 220 286
#>              B2     55 121 187 253 319
#>           c  B1     33  99 165 231 297
#>              B2     66 132 198 264 330
#>        W4 a  B1     15 105 195 285 375
#>              B2     60 150 240 330 420
#>           b  B1     30 120 210 300 390
#>              B2     75 165 255 345 435
#>           c  B1     45 135 225 315 405
#>              B2     90 180 270 360 450
#>        W5 a  B1     19 133 247 361 475
#>              B2     76 190 304 418 532
#>           b  B1     38 152 266 380 494
#>              B2     95 209 323 437 551
#>           c  B1     57 171 285 399 513
#>              B2    114 228 342 456 570
#> U'2 V1 W1 a  B1      2  14  26  38  50
#>              B2      8  20  32  44  56
#>           b  B1      4  16  28  40  52
#>              B2     10  22  34  46  58
#>           c  B1      6  18  30  42  54
#>              B2     12  24  36  48  60
#>        W2 a  B1      6  42  78 114 150
#>              B2     24  60  96 132 168
#>           b  B1     12  48  84 120 156
#>              B2     30  66 102 138 174
#>           c  B1     18  54  90 126 162
#>              B2     36  72 108 144 180
#>        W3 a  B1     10  70 130 190 250
#>              B2     40 100 160 220 280
#>           b  B1     20  80 140 200 260
#>              B2     50 110 170 230 290
#>           c  B1     30  90 150 210 270
#>              B2     60 120 180 240 300
#>        W4 a  B1     14  98 182 266 350
#>              B2     56 140 224 308 392
#>           b  B1     28 112 196 280 364
#>              B2     70 154 238 322 406
#>           c  B1     42 126 210 294 378
#>              B2     84 168 252 336 420
#>        W5 a  B1     18 126 234 342 450
#>              B2     72 180 288 396 504
#>           b  B1     36 144 252 360 468
#>              B2     90 198 306 414 522
#>           c  B1     54 162 270 378 486
#>              B2    108 216 324 432 540
#>     V2 W1 a  B1      4  28  52  76 100
#>              B2     16  40  64  88 112
#>           b  B1      8  32  56  80 104
#>              B2     20  44  68  92 116
#>           c  B1     12  36  60  84 108
#>              B2     24  48  72  96 120
#>        W2 a  B1      8  56 104 152 200
#>              B2     32  80 128 176 224
#>           b  B1     16  64 112 160 208
#>              B2     40  88 136 184 232
#>           c  B1     24  72 120 168 216
#>              B2     48  96 144 192 240
#>        W3 a  B1     12  84 156 228 300
#>              B2     48 120 192 264 336
#>           b  B1     24  96 168 240 312
#>              B2     60 132 204 276 348
#>           c  B1     36 108 180 252 324
#>              B2     72 144 216 288 360
#>        W4 a  B1     16 112 208 304 400
#>              B2     64 160 256 352 448
#>           b  B1     32 128 224 320 416
#>              B2     80 176 272 368 464
#>           c  B1     48 144 240 336 432
#>              B2     96 192 288 384 480
#>        W5 a  B1     20 140 260 380 500
#>              B2     80 200 320 440 560
#>           b  B1     40 160 280 400 520
#>              B2    100 220 340 460 580
#>           c  B1     60 180 300 420 540
#>              B2    120 240 360 480 600
ftable(einstein.tensor(A,U="U'",mark(B,"k"),V="Vk",W="Wk"))
#>     Uk    a    b    c
#> U'                   
#> U'1    1945 2045 2145
#> U'2    2090 2200 2310
ftable(einstein.tensor(A,U="U'",mark(B,"k"),V="Vk",W="Wk",1/10))
#>     Uk     a     b     c
#> U'                      
#> U'1    194.5 204.5 214.5
#> U'2    209.0 220.0 231.0
ftable(einstein.tensor(A,U="U'",mark(B,"k"),V="Vk",W="Wk",diag=to.tensor(c(1,1/10,1/100),c(Uk=3))))
#>     Uk       a       b       c
#> U'                            
#> U'1    1945.00  204.50   21.45
#> U'2    2090.00  220.00   23.10

dim(A[[U=~M]])
#> M V W 
#> 2 2 5 
A[[U=~M]] 
#> , , 1
#> 
#>       V
#> M      [,1] [,2]
#>   [1,]    1    3
#>   [2,]    2    4
#> 
#> , , 2
#> 
#>       V
#> M      [,1] [,2]
#>   [1,]    5    7
#>   [2,]    6    8
#> 
#> , , 3
#> 
#>       V
#> M      [,1] [,2]
#>   [1,]    9   11
#>   [2,]   10   12
#> 
#> , , 4
#> 
#>       V
#> M      [,1] [,2]
#>   [1,]   13   15
#>   [2,]   14   16
#> 
#> , , 5
#> 
#>       V
#> M      [,1] [,2]
#>   [1,]   17   19
#>   [2,]   18   20
#> 
#> attr(,"class")
#> [1] "tensor"
A[[U=~M,V=~"L"]] 
#> , , 1
#> 
#>       L
#> M      [,1] [,2]
#>   [1,]    1    3
#>   [2,]    2    4
#> 
#> , , 2
#> 
#>       L
#> M      [,1] [,2]
#>   [1,]    5    7
#>   [2,]    6    8
#> 
#> , , 3
#> 
#>       L
#> M      [,1] [,2]
#>   [1,]    9   11
#>   [2,]   10   12
#> 
#> , , 4
#> 
#>       L
#> M      [,1] [,2]
#>   [1,]   13   15
#>   [2,]   14   16
#> 
#> , , 5
#> 
#>       L
#> M      [,1] [,2]
#>   [1,]   17   19
#>   [2,]   18   20
#> 
#> attr(,"class")
#> [1] "tensor"