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MaplePrimes Activity

These are questions asked by ComputerUser

How to use Fourier transform to extract the part of data which higher than near flat data no matter of scale such as very small decimal value?

would like to extract part when very small decimal small start to increasing or a noise start to appear in time series data.

and then highlight with rectangle in plot for that part of data.

if Fourier transform can not detect this noise or an increasing data or spike then return 0, if detected then return 1

2.22 *10^(-87)

2.55 *10^(-90)

would like to get 2.22 and 2.55 only by ignoring any power

how to do this?

is there any library or tools to design index of Grassmannian and its k and n for Schubert use?

is there any library to relate poset with index of Grassmannian and its k and n for Schubert use

R := PolynomialRing([x, y, z]);
p1 := x^2+5-2*x*z;
p2 := z^3*y+x*y^2;
p3 := -8*z^3+3*y^2;
F := [p1, p2, p3];
MainVariable(p1, PolynomialRing([x, y, z]));
MainVariable(p1, PolynomialRing([z, y, x]));
prem(p1, p2, x);
prem(p2, p1, z);
prem(p3, p2, y);
premcustom := proc(Fparam,Gparam, xparam)
local R, G, F, lcg, lcr, dr, dg:
R := Fparam:
G := Gparam:
F := Fparam:
if degree(G,xparam) = 0 then
 print("return 0"):
 return 0:
elif degree(F, xparam) < degree(G, xparam) then
 print("return R"):
 return R:
 lcg := coeff(G, xparam, degree(G, xparam)):
 dg := degree(G, xparam):
 while degree(R, xparam) > degree(G, xparam) do
  lcr := coeff(R, xparam, degree(R, xparam)):
  dr := degree(R, xparam):
  R := lcg * R - lcr * G * (x^(dr - dg)):
end if:
return R:
end proc:
coeff(p1, x, degree(p1, x));
coeff(p2, x, degree(p2, x));

why premcustom looping?
is this coeff(p1, x, degree(p1, x)); wrong ?
should this to get real coefficient in number instead of variable and how?
is there equivalent function as dprem?
FlessThanG := proc(Fparam, Gparam, PRing)
F := Fparam:
G := Gparam:
if leader(F,PRing) < leader(G,PRing) or (leader(F,PRing) = leader(G,PRing) and degree(F, leader(F,PRing)) < degree(G, leader(G,PRing))) then
 return True:
 return False:
end if:
end proc:
dprem := proc(Fparam, Gparam, x, PRing)
local R, theta, thetax, thetaG, F, G;
F := Fparam:
G := Gparam:
R := F:
thetax := leader(G, PRing);
while FlessThanG(R, G, PRing) or FlessThanG(G, R, PRing) do
theta := leader(R, PRing);
R := prem(R, thetaG, theta)
return R:
end proc:
R := differential_ring(ranking = [[x,y,r]], derivations = [t], field_of_constants=[m,l], notation = diff):
p1 := m*x[2] + r*x;
p2 := m*y[2] + r*y - g;
p3 := x^2 + y^2 - l^2;
dprem(p1, p3, x, R);
is x[2] = diff(x,t$2) in diffalg ?
if not how to write in this way?
i had defined constant
but got error
Error, (in DifferentialAlgebra:-Tools:-LeadingDerivative) unknown symbol (approx. error location: [m*x[2 --> ] <-- +r*x])


matrix([[1,0],[0,1]]) * matrix[[y],[y']]
= a system 


how to get back matrix([[1,0],[0,1]]) from this system in general method if the system is very large?

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