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Creates random weyl objects: quick-and-dirty examples of Weyl algebra elements

Usage

rweyl(nterms = 3, vals = seq_len(nterms), dim = 3, powers = 0:2)
rweyll(nterms = 15, vals = seq_len(nterms), dim = 4, powers = 0:5)
rweylll(nterms = 50, vals = seq_len(nterms), dim = 8, powers = 0:7)

Arguments

nterms

Number of terms in output

vals

Values of coefficients

dim

Dimension of weyl object

powers

Set from which to sample the entries of the index matrix

Details

Function rweyl() creates a smallish random Weyl object; rweyll() and rweylll() create successively more complicated objects.

These functions use spray::rspray(), so the note there about repeated rows in the index matrix resulting in fewer than nterms terms applies.

Function rweyl1() returns a one-dimensional Weyl object.

Value

Returns a weyl object

Author

Robin K. S. Hankin

Examples

rweyl()
#> A member of the Weyl algebra:
#> +3*x^2*dy +2*x^2*z^2*dy +x*y^2*dx*dy*dz^2
rweyll()
#> A member of the Weyl algebra:
#> +15*x2^4*x3*x4^4*d2^2 +x1^5*x2^2*x4*d1^4*d2^3*d3^3
#> +3*x1*x2^5*x3^2*x4^2*d1^4*d2^3*d3^2*d4^2 +6*x2^4*x4*d1^3*d4^2
#> +4*x2*x3*x4^3*d1^4*d2^3*d3^3*d4^4
#> +8*x1^5*x2*x3^5*x4^3*d1^5*d2^4*d3^5*d4
#> +14*x2^4*x3^3*x4^5*d1^2*d2^4*d4^2 +5*x1^5*x2*x4*d1^3*d2^5*d4^2
#> +10*x3*d1^3*d2*d3^4*d4^4 +9*x1^5*x2*x3^4*x4^3*d1^4*d2*d3*d4^3
#> +11*x1^2*x2^3*x3^3*x4*d1^5*d2^2*d3^2*d4^4
#> +7*x1^3*x2^4*x3^4*x4^2*d1^3*d2^3*d3^4*d4^5
#> +2*x1^4*x3*x4*d1^5*d2*d3^5*d4 +12*x1^2*x3*x4^3*d1^5*d2^4*d3^4*d4^4
#> +13*x1^2*x2^2*x3^4*x4^4*d1^2*d2*d3*d4^4
rweyl(d=7)
#> A member of the Weyl algebra:
#> +3*x1*x2^2*x7*d2^2*d3^2*d4^2*d5*d6*d7^2
#> +2*x1*x3^2*x5^2*d1*d2^2*d3^2*d4^2*d5^2*d6^2
#> +x1*x2*x3*x4^2*x5^2*x6^2*x7*d1*d2^2*d4*d5^2*d6^2*d7

options(polyform = TRUE)
rweyl1()
#> A member of the Weyl algebra:
#> +5*x^3*d +4*x^3*d^2 +2*x^3*d^3 +6*x^2*d +3*x*d +x^4*d^4
options(polyform = FALSE) # restore default