Kitonum

15202 Reputation

24 Badges

12 years, 70 days

MaplePrimes Activity


These are replies submitted by Kitonum

Formulation of the problem is unclear!  What is 10P4?

I agree that the machinery of the bug is still unclear. But why my code can not be treated as a workaround? Here's another variant for any range:

restart;

X:=[seq(k, k=-20..20, 0.1)]:

Y:=[]:

for k from 1 to 401 do

a:=solve(eval(sqrt(x^2+y^2)=sqrt((x-4)^2+(y-3)^2)+5, x=X[k])):

if a<>NULL then

Y:=[op(Y), [X[k], a]]: fi:

od:

plot(Y, thickness=3, scaling=constrained, view=[-20..20, -16..16]);

Your plot can be constructed as follows:

X:=[seq(k, k=4..10, 0.1)]:

Y:=[]:

for k from 1 to 61 do

solve(eval(sqrt(x^2+y^2)=sqrt((x-4)^2+(y-3)^2)+5, x=X[k])):

Y:=[op(Y), [X[k], %]]:

od:

plot(Y, thickness=3, view=[-1..10, -1..8]);

1) To Alejandro Jakubi.

Thanks for the detailed explanation! It is unfortunate that Maple unable to cope with checking obvious statements.  

Another example:

is(2*х^5 +1>0) assuming x>=0, x<=1;

                     false

This is just a bug!

 

2) To Markiyan Hirnyk.

I think that the use of  continuous=true option, without proof of the convergence of the improper integral, is unacceptable because may result in an error.

An example:

int(1/x, x=-1..2, continuous=true);

             -Pi*I+ln(2)

Received an incorrect result!

1) To Alejandro Jakubi.

Thanks for the detailed explanation! It is unfortunate that Maple unable to cope with checking obvious statements.  

Another example:

is(2*х^5 +1>0) assuming x>=0, x<=1;

                     false

This is just a bug!

 

2) To Markiyan Hirnyk.

I think that the use of  continuous=true option, without proof of the convergence of the improper integral, is unacceptable because may result in an error.

An example:

int(1/x, x=-1..2, continuous=true);

             -Pi*I+ln(2)

Received an incorrect result!

@Markiyan Hirnyk 

1) Why was the combinat package called, if in the code it is not used?  

2) Your procedure s does not work in the classic interface, as left single quotes should be used: print(`Invalid input`) . In standard interface s works - Maple interprets a blank as multiplication.    

3) A simple exhaustive search program more effective (running at least 10 times faster)

s1:=proc(L::list)

local n, N, i, j;

n:=nops(L);

if nops(convert(L,set))=n then

N:=0;

for i to n-1 do

for j from i+1 to n do

if L[i]>L[j] then N:=N+1; fi;

od; od;

else print(`Invalid input`); fi;

(-1)^N;

end proc;

 

Examples:

L:=combinat[randperm](1000):

st:=time():

s1(L), time()-st;

    1,  0.967

 

st:=time():

s(L), time()-st;

    1,  11.981

@Markiyan Hirnyk 

1) Why was the combinat package called, if in the code it is not used?  

2) Your procedure s does not work in the classic interface, as left single quotes should be used: print(`Invalid input`) . In standard interface s works - Maple interprets a blank as multiplication.    

3) A simple exhaustive search program more effective (running at least 10 times faster)

s1:=proc(L::list)

local n, N, i, j;

n:=nops(L);

if nops(convert(L,set))=n then

N:=0;

for i to n-1 do

for j from i+1 to n do

if L[i]>L[j] then N:=N+1; fi;

od; od;

else print(`Invalid input`); fi;

(-1)^N;

end proc;

 

Examples:

L:=combinat[randperm](1000):

st:=time():

s1(L), time()-st;

    1,  0.967

 

st:=time():

s(L), time()-st;

    1,  11.981

s([1, 2, 3, 4]);

             -1

No comments!

s([1, 2, 3, 4]);

             -1

No comments!

Many thanks to all for the detailed comments and answers!

Mathematica immediately finds the correct answer:

N[FractionalPart[10^9*Exp[1]], 10]

0.4590452354

The coordinates of T and E are the rational numbers, what you would like!

The coordinates of T and E are the rational numbers, what you would like!

To toandhsp! I solved your problem by Classic Worksheet Maple 13  (time about 6 min).

To Markiyan Hirnyk! Your solving found only 98 solutions (and accurate of them will be 50). Therefore, I believe that the application of DirectSearch package for these tasks is inefficient. It is interesting your comment on this.

To toandhsp! I solved your problem by Classic Worksheet Maple 13  (time about 6 min).

To Markiyan Hirnyk! Your solving found only 98 solutions (and accurate of them will be 50). Therefore, I believe that the application of DirectSearch package for these tasks is inefficient. It is interesting your comment on this.

First 104 105 106 107 108 109 110 Page 106 of 112