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Seldom to ask question after retired math hobby Just waiting for beauty who born in 1994 And waited for her email to mavio@protonmail.com What is the difference in ownership among different universe?

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These are questions asked by ComputerUser

How to filter the terms which has power ...

ComputerUser 535 Maple 12
algebra
April 01 2018
1 0

For example

if x*y*z+ x*y^2

after filter 

x*y*z

how to convert this matlab code and use ...

ComputerUser 535 Maple 12
procedure matlab
March 28 2018
0 0
i have two functions , first naive function has error after used.
 
if run FromMatlab, does it mean that do not need to copy the result and run again because it had already run?
as i do not understand the output code after translated.
 
there is syntax error when translate second function
 
with(Matlab):
FromMatlab("function X = sylv_naive(A,B,Q)
% X=SYLV_NAIVE(A,B,Q) solves the Sylvester equation AX + XB = Q
%    A, B, Q: matrix coefficients
%    X : solution of AX + XB = Q
[m,n] = size(Q);
H = kron(eye(n), A) + kron(B.', eye(m));
Qvec = reshape(Q,m*n,1);
Xvec = H\Qvec;
X = reshape(Xvec,m,n);
");
sylv_naive(Jesus7,Jesus7,Matrix([[0,0],[0,0]]));
sylv_naive(Jesus7,Jesus7,Matrix([[0],[0]]));
Error, (in ArrayTools:-Reshape) the desired output contains a different number of elements than the input
 
 
 
with(Matlab):
FromMatlab("function X = sylvester(A,B,Q)
% X=SYLVESTER(A,B,Q) solves the Sylvester equation AX + XB = Q
% by using the Bartels and Stewart algorithm based on the complex
% Schur decomposition
%    A, B, Q: matrix coefficients
%    X : solution of AX + XB = Q
[m,n] = size(Q);
[U,A1] = schur(A,'complex');
[V,B1] = schur(B.','complex');
Q1 = U'*Q*conj(V);
X = zeros(m,n);
X(:,n) = (A1 + B1(n,n)*eye(m))\Q1(:,n);
for i = n-1:-1:1
    v = Q1(:,i) - X(:,i+1:n)*B1(i,i+1:n).';
    X(:,i) = (A1 + B1(i,i)*eye(m))\v;
end
X = U*X*V.';");

Error, (in Matlab:-FromMatlab) on line 15, syntax error
    X(:,i) = (A1 + B1(i,i)*eye(m))
 
 

how to find the necessary and sufficient...

ComputerUser 535 Maple 12
solve
March 26 2018
1 4

if known solution [a,b,c,d]

solve([eq2, eq3, eq4, ....], [a,b,c,d])

but not equal to known solution a,b,c,d even if number of equations more than number of variables.

then guess that there are some necessary and sufficient conditions unknown.

how to find the necessary and sufficient conditions from solutions?

is there options to set for this?

or can eliminate function help to find necessary and sufficient conditions and how to do?

 

 

 

How to enumerate a complete set of patte...

ComputerUser 535 Maple 12
string
March 21 2018
0 0

Is it possible to use Regex to generate a complete list of patterns?

for search pattern in a list of characters

how to sort hashtable?...

ComputerUser 535 Maple 12
sort table
March 18 2018
1 0

A[k]:= x;
A:= table().

how to sort hashtable by key which is a list of matrix

after sort, is possible to group by key? and how?

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