Mac Dude

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8 years, 45 days

MaplePrimes Activity


These are replies submitted by Mac Dude

to the OP: Note that Preben supplies initial values. Your fitting problem is nonlinear and requires an iterative process that starts from somewhere. If your starting (or initial-) values are not good; it may never find the minimum (or the wrong one). If you don't supply initial values I would guess Maple uses 0 which may not be a good starting point.

Mac Dude

@acer: You read it right. I inadvertently copied a test case; in the production that function does depend on the integration variable ener. Conclusions do not change, however: this particular example does not appear to execute in parallel under Threads:-Seq.

Pity.

M.D.

@acer: You read it right. I inadvertently copied a test case; in the production that function does depend on the integration variable ener. Conclusions do not change, however: this particular example does not appear to execute in parallel under Threads:-Seq.

Pity.

M.D.

@itsme: Thanks, yes this works for me.

 

M.D.

@itsme: Thanks, yes this works for me.

 

M.D.

@oforion 

To define a function, you can use the -> operator:

S:=k->sqrt(add(k[i],i=1..op(1,k)));

Define a vector:

k5:=Vector([1,2,3,4,5]);

and call your function:

S(k5);

which is √15.

To manipulate your vector; you do not need a function per se, you can just assign the expression to a name & go at it. You should have a copy of the Maple User Manual, these things are explained in there. If you don't have it; it is available for d/l @ the Maplesoft site.

Mac Dude

@oforion 

To define a function, you can use the -> operator:

S:=k->sqrt(add(k[i],i=1..op(1,k)));

Define a vector:

k5:=Vector([1,2,3,4,5]);

and call your function:

S(k5);

which is √15.

To manipulate your vector; you do not need a function per se, you can just assign the expression to a name & go at it. You should have a copy of the Maple User Manual, these things are explained in there. If you don't have it; it is available for d/l @ the Maplesoft site.

Mac Dude

For "updated" you may read "assigned".

I am getting the point you are making. The "details of the printing mechanism" (=bugs??) are unsettling to a (still) relative newbie struggling with both the Maple system as well as the formulation of the problem (s)he is actually trying to solve.

In the meantime with the same project I have run into another idiosyncrasy involving records; but I need to first isolate the problem so I can post a simple example. Please stay tuned...

Thanks,

M. D.

For "updated" you may read "assigned".

I am getting the point you are making. The "details of the printing mechanism" (=bugs??) are unsettling to a (still) relative newbie struggling with both the Maple system as well as the formulation of the problem (s)he is actually trying to solve.

In the meantime with the same project I have run into another idiosyncrasy involving records; but I need to first isolate the problem so I can post a simple example. Please stay tuned...

Thanks,

M. D.

@acer: Your interpretation makes sense to me.

Per your last paragraph, I will expect rtables to not get evaluated when passed as a parameter; effectively giving them temporary last-name evaluation type. At the same time, lists will get evaluated fully as the rationale for not doing so isn't present with the immutable structures like lists. This difference in behaviour is good to know and remember. I actually ran against the evaluation of lists already once, when I needed to get at the names of the elements of a list which was passed to a proc; I had to use the ::uneval modifier in the parameter definition of the proc to get at those names. So now I understand why. I do wonder whether all this is unnecessarily complicated, but then, I haven't done enough with Maple yet to make such a statement.

Anyway, I gained some more insight, thanks.

M. D.

@acer: Your interpretation makes sense to me.

Per your last paragraph, I will expect rtables to not get evaluated when passed as a parameter; effectively giving them temporary last-name evaluation type. At the same time, lists will get evaluated fully as the rationale for not doing so isn't present with the immutable structures like lists. This difference in behaviour is good to know and remember. I actually ran against the evaluation of lists already once, when I needed to get at the names of the elements of a list which was passed to a proc; I had to use the ::uneval modifier in the parameter definition of the proc to get at those names. So now I understand why. I do wonder whether all this is unnecessarily complicated, but then, I haven't done enough with Maple yet to make such a statement.

Anyway, I gained some more insight, thanks.

M. D.

Thanks. I hope someone @ Maplesoft sees this & gets it fixed.

 

M.D.

Thanks. I hope someone @ Maplesoft sees this & gets it fixed.

 

M.D.

acer, thanks very much for this clear and comprehensive expose of the diff between list and Vectors, which as I said before I had not appreciated. I certainly did not realize that I cannot really change an element of a list, an operation I need to do often (and am doing on elements of Vectors). Is this what the page you referred me to is calling "being mutable"?

M.D.

acer, thanks very much for this clear and comprehensive expose of the diff between list and Vectors, which as I said before I had not appreciated. I certainly did not realize that I cannot really change an element of a list, an operation I need to do often (and am doing on elements of Vectors). Is this what the page you referred me to is calling "being mutable"?

M.D.

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