Wedge products of \(k\)-forms

wedge2(K1,K2)
wedge(x, ...)

Arguments

K1,K2,x,...

\(k\)-forms

Details

Wedge product of \(k\)-forms.

Value

The functions documented here return an object of class kform.

Author

Robin K. S. Hankin

See also

Note

In general use, use wedge() or ^ or %^%, as documented under Ops. Function wedge() uses low-level helper function wedge2(), which takes only two arguments.

A short vignette is provided with the package: type vignette("wedge") at the commandline.

Examples


k1 <- as.kform(cbind(1:5,2:6),1:5)
k2 <- as.kform(cbind(5:7,6:8,7:9),1:3)
k3 <- kform_general(1:6,2)

a1 <- wedge2(k1,wedge2(k2,k3))
a2 <- wedge2(wedge2(k1,k2),k3)

is.zero(a1-a2)  # NB terms of a1, a2 in a different order!
#> [1] TRUE

# This is why wedge(k1,k2,k3) is well-defined.  Can also use ^:
k1 ^ k2 ^ k3
#> An alternating linear map from V^7 to R with V=R^9:
#>                    val
#>  2 3 4 5 7 8 9  =   27
#>  1 2 3 5 6 7 8  =    6
#>  1 2 5 6 7 8 9  =   18
#>  1 3 4 5 6 7 8  =   14
#>  1 2 4 6 7 8 9  =    3
#>  2 3 5 6 7 8 9  =   21
#>  1 3 4 5 7 8 9  =   21
#>  2 3 4 6 7 8 9  =   15
#>  2 4 5 6 7 8 9  =   27
#>  1 2 3 5 7 8 9  =    9
#>  1 2 3 4 5 6 7  =    6
#>  1 2 4 5 6 7 8  =   10
#>  3 4 5 6 7 8 9  =   36
#>  1 4 5 6 7 8 9  =   27
#>  1 2 4 5 7 8 9  =   15
#>  1 2 3 4 6 7 8  =   12
#>  2 3 4 5 6 7 8  =   18
#>  1 2 3 6 7 8 9  =    9
#>  1 2 3 4 7 8 9  =   18
#>  1 3 5 6 7 8 9  =   15
#>  1 3 4 6 7 8 9  =    9