vv

13837 Reputation

20 Badges

9 years, 326 days

MaplePrimes Activity


These are replies submitted by vv

@roubeur 

Probably you did not execute the initialization part; it is better to upload the worksheet in such situations.
Here is a slight modification of the worksheet; just change ee and execute it.

boolean-n.mw

@roubeur 

To go back to the initial variables do:

eval(simp, varsx =~ vars);

The admisible solution xxx was obtained using random numbers. If you re-execute the computation (without restart) xxx will change, so it is normal that you obtained another result (simp).

Note: for some admisible xxx, it could be possible that very few variables must be fixed.
You should experiment.

@acer 

Indeed, in Qgr (in 2d)

Representative(a) . Representative(b)

was parsed as:

Typesetting:-delayDotProduct(Representative(a), Representative(b));

Works without errors in Maple 2017.3.

You should try to present the mathematical problem.
Otherwise, for suggestions or alternate solutions a "reverse engineering" of the Maple code will be necessary.

@Rouben Rostamian  

For an "lndirect documentation" see showstat(log).

@Carl Love 

I was also curious to understand on what basis Maple returns true for is(exp(2),irrational);
This information should (probably) be found in
`property/exp` but it's not there.
It would be very disappointing if the answer is obtained using approximations because Digits cannot be set to infinity and the answer is simply a guess in this case.

is(x,irrational) seems indeed to be a pure guess because of:

is(sum(10^(-k^3),k=1..infinity), irrational);
        false

 


 

 

@Rouben Rostamian  

If f is the name of a procedure then  f[u](x)  actually calls  f(x), but in the body of f the index/indices
u can be retrived (and used) via  op(procname).
To check whether f is invoked with an index one may use  type(procname,indexed).

(I am not sure whether this is documented, but I found about it long time ago in a Maple book which I do not remember). 

@Carl Love 

But ?type,property clearly says:

Note: Types are properties, but not all properties are types.

Do you know a type which is not property? (I don't mean "proper").

@Jason Lee 

interface(rtablesize=20);

10

(1)

A := Matrix([[4, 7, 5, 2, 6, 4, 9, 7, 5, 8, 5], [7, 7, 3, 9, 4, 5, 2, 3, 5, 6, 8], [5, 6, 5, 6, 6, 3, 7, 4, 9, 1, 9], [9, 1, 4, 8, 9, 4, 4, 2, 1, 3, 3], [5, 6, 8, 2, 2, 1, 2, 9, 5, 4, 1], [4, 7, 9, 6, 9, 2, 3, 5, 6, 3, 5], [7, 2, 5, 7, 3, 4, 9, 8, 1, 8, 9], [5, 7, 1, 2, 7, 9, 9, 2, 2, 4, 7], [1, 6, 5, 3, 9, 9, 1, 5, 7, 4, 2], [3, 7, 8, 7, 8, 3, 6, 4, 6, 9, 2]]);

_rtable[18446744074327622950]

(2)

Select the 6-th column

b:=A[..,6];

_rtable[18446744074362862038]

(3)

Select the desired columns from A

C:=A[..,[1..5,7..11]];

_rtable[18446744074362856622]

(4)

The linear system (matrix form)   C.x = b   has the solution  x = C^(-1) . b   (provided that C is not singular)

C^(-1) . b;

_rtable[18446744074362839518]

(5)

The 6-th element of the solution vector:

%[6];

63695593/46022164

(6)

Note that C is indeed nonsingular:

LinearAlgebra:-Determinant(C);

-92044328

(7)

 

 

Download linsyst.mw

@Jason Lee 

What exactly is not clear? I have used your notations.
But I just noticed that you are using Maple T.A. and I am not sure whether this works here.

@Carl Love 

Why dou you think that is is using list(rational) as a type? Of course, any type is a property.

is(list(rational), property);
   true

type(list(rational), property);
    true

Probably your notion of "proper property" is useful.

 

@_Maxim_ 

Of course is uses simplifications. It should  return FAIL much more frequently (when in doubt)  but it does not probably for "commercial" reasons; it prefers `false`. The assume facility deserves a much more careful implementation.

Surprisingly:
is(exp(1)+Pi,irrational);
    FAIL
So, it seems that is adopts a special strategy for properties which are not types.

 

Also:

is(Pi,irrational);
                              true
is(Pi^2,irrational);
                              FAIL
is(exp(1),irrational);
                              true
is(exp(1)^2,irrational);
                              FAIL
is(exp(2),irrational);
                              true

is(exp(sqrt(2)),irrational); #does not know Lindemann theorem (from 1882!)
                              FAIL

 

 

@st104290 

As you see in the example, sort itself does not alter the terms. Probably you have used some other command.
You may append assuming t>0  to that command.

@Markiyan Hirnyk 

As always you want to have the final word even when you are wrong.
But two pages earlier Fichtenholz states:  "generalized sum" (in the sense of Poisson).
He also says that actually Abel was not interested in the summation of divergent series.

Note.
In 1828 Abel wrote `Divergent series are the invention of the devil, and
it is shameful to base on them any demonstration whatsoever.'

[Abel died in 1829]

First 107 108 109 110 111 112 113 Last Page 109 of 176