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Ronan

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14 years, 32 days
East Grinstead, United Kingdom
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Equations are acting inert...

Ronan 1401 Maple 2022
procedure local
October 10 2022
1 1

I have a matrix and generate difference tables from it's diagonals. Works fine. Then I make a polynomial from the first row of the difference table. I have three polynomials. They are all acting inert, just will not evaluate.

I cannot see what the problem is.
 

restart

interface(rtablesize = 12)

[10, 10]

i) Recurrence relation

 

"Recurrence Relation for next column. . The matrix starts at 1,1 not 0,0 A(i,j)=A(i-1,j-1)*(j-2)+A(i,j-1)"
``

NULL``

Msize := 12

A := Matrix(Msize)

A[1, 1] := 1

1

for i from 2 to Msize do for j from i to Msize do A[i, j] := A[i, j-1]*(j-2)+A[i-1, j-1] end do end do

A

Matrix(%id = 36893489695842121836)

``

``

viia)  General formula for diagonals:-

Select diagonal  & Difference Table procedures

 

diag := proc (M::Matrix, dg::posint) local i, rd, c, dt; rd := LinearAlgebra:-RowDimension(M); dt := Matrix(rd, rd); for i from dg to rd do dt[1+i-dg, 1] := M[1+i-dg, i] end do; return dt end proc

proc (M::Matrix, dg::posint) local i, rd, c, dt; rd := LinearAlgebra:-RowDimension(M); dt := Matrix(rd, rd); for i from dg to rd do dt[1+i-dg, 1] := M[1+i-dg, i] end do; return dt end proc

diag(A, 5)

Matrix(%id = 36893489695866397388)

diftab := proc (M::Matrix) local i, j, cl, rd; rd := LinearAlgebra:-RowDimension(M); for i from rd by -1 to 1 do if M[i, 1] = 0 then rd := rd-1 else break end if end do; cl := rd; for i from 2 to cl do for j to rd-i do M[j, i] := M[j+1, i-1]-M[j, i-1] end do end do; print(M); return M end proc

proc (M::Matrix) local i, j, cl, rd; rd := LinearAlgebra:-RowDimension(M); for i from rd by -1 to 1 do if M[i, 1] = 0 then rd := rd-1 else break end if end do; cl := rd; for i from 2 to cl do for j to rd-i do M[j, i] := M[j+1, i-1]-M[j, i-1] end do end do; print(M); return M end proc

diftab(diag(A, 4))

Matrix(%id = 36893489695866348116)

gnrpoly := proc (M::Matrix) local i, p, rd, n; rd := LinearAlgebra:-RowDimension(M); for i from rd by -1 to 1 do if M[1, i] = 0 then rd := rd-1 else break end if end do; p := 0; for i from 0 to rd-1 do p := p+M[1, i+1]*binomial(n, i) end do; return p end proc

proc (M::Matrix) local i, p, rd, n; rd := LinearAlgebra:-RowDimension(M); for i from rd by -1 to 1 do if M[1, i] = 0 then rd := rd-1 else break end if end do; p := 0; for i from 0 to rd-1 do p := p+M[1, i+1]*binomial(n, i) end do; return p end proc

"for i from 0 to 3 do print("Diagonal ",i); eqn:=gnrpoly(diftab(diag(A,i+1))); cat(poly,i):=unapply(factor(expand(eqn)),n); print("--------------------------------------------------------------"); end do"

"--------------------------------------------------------------"

NULL

``

``

The equations do not evaluate. They are acting inert

poly1(n)

(1/2)*n*(1+n)

poly1(2)

(1/2)*n*(1+n)

poly2(n)

(1/24)*n*(3*n+5)*(n+2)*(n+1)

poly2(3)

(1/24)*n*(3*n+5)*(n+2)*(n+1)

poly3(n)

(1/48)*n*(n+1)*(n+3)^2*(n+2)^2

poly3(-1)

(1/48)*n*(n+1)*(n+3)^2*(n+2)^2

eqn

6*n+38*binomial(n, 2)+93*binomial(n, 3)+111*binomial(n, 4)+65*binomial(n, 5)+15*binomial(n, 6)

value(eval(eqn, n = 4))

6*n+38*binomial(n, 2)+93*binomial(n, 3)+111*binomial(n, 4)+65*binomial(n, 5)+15*binomial(n, 6)

eqn1 := expand(eqn)

(3/4)*n+2*n^2+(97/48)*n^3+(47/48)*n^4+(11/48)*n^5+(1/48)*n^6

eval(eqn1, [n = 4])

(3/4)*n+2*n^2+(97/48)*n^3+(47/48)*n^4+(11/48)*n^5+(1/48)*n^6

NULL


 

Download Q_10-10-22_gentrate_eqn.mw

Test if question...

Ronan 1401 Maple 2022
syntax if-then exprseq
September 18 2022
1 3

I have a whole lot of conditions to test on the signum of answers. This gets difficult to read so I am wondering could something like the following be done?

a, b, c, d := 1, -1, 1, -1;
if a, b, c, d = 1, 0, -1, -1 then
    print("foo");
end if;

The above obviously doesn't work. The reason I would like to do this is it would be simple to read the patterns of 1's and 0's.

Any ideas?

Select powers and coeffs on a general ty...

Ronan 1401 Maple
coeff coefficients incomplete-question
September 11 2022
2 2

I was experimenting on and found coeff and degrees  do not work with algebraic type powers. So I set aboud dismanteling  a example polynomial. I certainly went around the houses doing this. I wanted to put the powers and coefficinets of x in an array.

I sure there must be a simpler way.

restart

NULLNULL

r := proc (x) options operator, arrow; a[0]+a[1]*x-a[2]*x^2+a[8]*x^(8/5)-a[h]*x^h+k*x^(-b/a) end proc

proc (x) options operator, arrow; a[0]+a[1]*x-a[2]*x^2+a[8]*x^(8/5)-a[h]*x^h+k*x^(-b/a) end proc

mnmls := [op(r(x))]

[a[0], a[1]*x, -a[2]*x^2, a[8]*x^(8/5), -a[h]*x^h, k*x^(-b/a)]

A := Array(1 .. 2, 1 .. nops(mnmls))

Array(%id = 36893489621187187044)

mnmls, x0 := selectremove(has, mnmls, x)

[a[1]*x, -a[2]*x^2, a[8]*x^(8/5), -a[h]*x^h, k*x^(-b/a)], [a[0]]

NULL

A[2, 1] := op(x0)

a[0]

coeff(r(x), x, 2)

Error, unable to compute coeff

coeffs(r(x), x)

Error, invalid arguments to coeffs

degree(mnmls[1], x)

1

degree(mnmls[4], x)

FAIL

degree(mnmls[5], x)

FAIL

indets(r(x))

{a, b, h, k, x, a[0], a[1], a[2], a[8], a[h], x^h, x^(-b/a), x^(8/5)}

bits := [seq([op(mnmls[i])], i = 1 .. nops(mnmls))]

[[a[1], x], [-1, a[2], x^2], [a[8], x^(8/5)], [-1, a[h], x^h], [k, x^(-b/a)]]

deeperbits := [seq(op(op(bits)[i]), i = 1 .. nops(bits))]

[a[1], x, -1, a[2], x^2, a[8], x^(8/5), -1, a[h], x^h, k, x^(-b/a)]

varpwrs, cofsl := selectremove(has, deeperbits, x)

[x, x^2, x^(8/5), x^h, x^(-b/a)], [a[1], -1, a[2], a[8], -1, a[h], k]

is(nops(vars) = nops(cofsl))

false

cofs := convert(cofsl, Array)

Array(%id = 36893489621220545228)

for i to numelems(cofs)-1 do if cofs[i] = -1 then cofs[i] := 0; cofs[i+1] := -cofs[i+1]; i = i+2 end if end do; cofs; cofs := remove[flatten](has, cofs, 0)

Array(%id = 36893489621220530764)

cofs

Array(%id = 36893489621220530764)

is(nops(vars) = numelems(cofs))

false

NULL

pwrs := `assuming`([simplify(`~`[log[x]](varpwrs))], [x > 0, a::'real', b::'real', h::'real'])

[1, 2, 8/5, h, -b/a]

A

Array(%id = 36893489621187187044)

for i to nops(mnmls) do A[1, i+1] := pwrs[i]; A[2, i+1] := cofs[i] end do; A

Array(%id = 36893489621187187044)

 

NULL


Download Q_11-9-22_monomial_powers_and_coeffs.mw

Remove limit from integration answer...

Ronan 1401 Maple 2022
integration assumptions assuming
September 09 2022
3 1

How should I handle the limit in the integration answe?. I don't see why it is necessary.

restart

_local(gamma)

p := `assuming`([proc (alpha) options operator, arrow; alpha^m end proc], [m]); LinearAlgebra:-Transpose(integer)

integer

q := `assuming`([proc (alpha) options operator, arrow; alpha^n end proc], [n]); LinearAlgebra:-Transpose(integer)

integer

Sa := eval((1/2)*(int(simplify(p(alpha)*(D(q))(alpha)), alpha = 0 .. 1)))

-(1/2)*(limit(alpha^(m+n), alpha = 0, right)-1)*n/(m+n)

s1 := eval((1/2)*(int(simplify(p(alpha)*(D(q))(alpha)), alpha)))

(1/2)*alpha^(m+n)*n/(m+n)

eval(s1, alpha = 1)-(eval(s1, alpha = 0))

(1/2)*n/(m+n)

NULL

Download Q_9-9-22_limit_in_integral.mw

Can I insert a Hyperlink to a Geogebra d...

Ronan 1401 Maple 2022
hyperlink geogebra
August 31 2022
2 7

I would like to insert a hyperling to a geogebra document but the hyperlink box deosn't appear to allow general files. Can this be done?

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