Home › Forums › General Discussion › Everything but...

Kernel connection lost

John Fredsted's picture
Posted on 2007-09-27 04:41 By John Fredsted (Maple Rating 4 566)
Categories:

In a previous thread I, most thankfully, learned that if B := A for some Array A, then B will not be a reinstantiation of A, which is most simply ascertained with the command eval(A = B) which here evaluates true.

On several occassions, though, I would like reinstantiation. This, I found out, can be done in at least two ways; B := Array(A), or B := map(eval,A). However, in such simple reinstantiations information about for instance any indexing functions of A is lost. But they can be propagated using the ArrayIndFns(...), as seen from

A := Array(symmetric,1..4,1..4):
B := Array(ArrayIndFns(A),A):
ArrayIndFns(A),ArrayIndFns(B),evalb(A = B);

On one occasion, though, I misspelled the ArrayIndFns as ArrayIndFcs, that is

A := Array(symmetric,1..4,1..4):
B := Array(ArrayIndFcs(A),A):
ArrayIndFns(A),ArrayIndFns(B),evalb(A = B);

and Maple responded with losing kernel connection. Can that be considered a bug?

‹ how maple inspires me - Cracking Source code of microcontroller ›
John Fredsted's picture

A little correction

Comment on 2007-09-27 04:51 from John Fredsted (Maple Rating 4 566)

eval(A = B) in the first paragraph should of course read evalb(A = B).

gkokovidis's picture

Maple 10 and Maple 11 Classic Interface

Comment on 2007-09-27 05:33 from gkokovidis (Maple Rating 4 677)

I tried your statements below with Maple 10 and 11 Classic interface. I never lost connection to the kernel. I also removed the restart commands to see if that made a difference. It did not. I just got an error message, as expected.

>restart:
>A := Array(symmetric,1..4,1..4):
>B := Array(ArrayIndFns(A),A):
>ArrayIndFns(A),ArrayIndFns(B),evalb(A = B);

symmetric, symmetric, false

>restart:
>A := Array(symmetric,1..4,1..4):
>B := Array(ArrayIndFcs(A),A):
>ArrayIndFns(A),ArrayIndFns(B),evalb(A = B);

Error, argument `Array(symmetric,1..4, 1..4, [[...],[...],[...],[...]], datatype = anything, storage = triangular[upper])` is incorrect or out of order

Error, invalid input: ArrayIndFns expects its 1st argument, A, to be of type Array, but received B

Regards,
Georgios Kokovidis

John Fredsted's picture

Classic Interface

Comment on 2007-09-27 13:12 from John Fredsted (Maple Rating 4 566)

Thanks for testing. I've just done the same test, using Maple 11 Classic Interface, and I get the same result as you do, i.e., no lost kernel connection.

Do you dare to test it using the non-classic interface?

gkokovidis's picture

Classic Interface

Comment on 2007-09-27 13:59 from gkokovidis (Maple Rating 4 677)

I lose the kernel connection with the non classic interface, with ver. 10 and 11.

Regards,
Georgios Kokovidis
Dräger Medical

John Fredsted's picture

To boldly go...

Comment on 2007-09-28 02:52 from John Fredsted (Maple Rating 4 566)

Thanks!

acer's picture

copy

Comment on 2007-09-27 08:12 from acer (Maple Rating 4 1357)

The copy() command should produce a copy of an Array along with the indexing function.

Eg, simply,

B := copy(A);

That should work for Array, Matrix, or Vector. It should also reproduce 'storage' and 'order'. The only thing that it does not reproduce, I believe, is the attribute readonly (which makes sense, to me, as I can't see why one would ever want two identical readonly objects).

acer

John Fredsted's picture

Super!

Comment on 2007-09-27 13:04 from John Fredsted (Maple Rating 4 566)

Very nice - I was not aware of that.

Comment viewing options

Select your preferred way to display the comments and click "Save settings" to activate your changes.
}