R: Move summation to the right

sumMoveIn {lazy.symbolic}

R Documentation

Move summation to the right

Description

Move summation to the right

Usage

sumMoveIn(sexpr, frombottom = 1, all = 0, verify = 1, debug = 0)

Arguments

`sexpr`	An expression containing summation
`frombottom`	= 1 to expand the bottom level summation
`all`	= 1 to move all the movable summations
`debug`	= 1 to print intermediate result

Details

s( s( a[i,j]*b[j,k]*c[k,l], {k}) , {j}) -->
 s( a[i,j]*s( b[j,k]*c[k,l], {k}) , {j})

It is assumed that the scope of the subscript does NOT depend on the other subscripts.

Examples

sumMoveIn( "s( s( a[i,j]*b[j,k]*c[k,l], {k}) , {j})" )
sumMoveIn( "s( s( a[i,j]/b[j,k]*c[k,l], {k}) , {j})" )
sumMoveIn( "s( s( c[k,l]/a[i,j]/b[j,k], {k}) , {j})" )

exp="s( x * s( s( a[i,j]*b[j,k]*c[k,l], {k}) , {j}),  {l})"
sumDisplay(exp) |> sumMoveIn(all=1) |> sumDisplay()

exp="s( x + s( s( a[i,j]*b[j,k]*c[k,l], {k}) - y, {j}),  {l})"
sumMoveIn( exp, all=1 )

sexpr="s(A[i,s1]*s(B[s1,s2]*C[s2,j]*D[j,j],{s2,1,S2}),{s1,1,S1})"
sexpr |> print() |> sumMoveIn()  |> print() |> sumMoveIn() |> print()
sumMoveIn(sexpr, all=1)

[Package lazy.symbolic version 1.0.0.20250425 ]