MaplePrimes Questions

Hello,

In the creation of package wrapping some procedures, may you tell me the differences between using a table or a module so as to wrap the procedures ?

In my case, it seems to me that table is more convenient since I can create with table packages while keeping my program with a structure of section, subsection, ...

But, I'm a beginner in the use of packages. Consequently, I'm very interested in your opinions on this question.

Thanks a lot for your help

hi,i am studying the maple most recent.But when calculating function integral,I ran into trouble.I hope to get your help.Here is the code I wrote, but it runs a very long time. How to effectively reduce the integration time?

restart;
with(student);
assume(n::integer);
Fourierf := proc (sigma, a, b, N) local A, A0, B, T, S, Ff; T := b-a; A0 := int(sigma, t = a .. b); A := int(sigma*sin(n*Pi*t/T), t = a .. b); B := int(sigma*cos(n*Pi*t/T), t = a .. b); S := sum(A*sin(n*Pi*t/T)+B*cos(n*Pi*t/T), n = 1 .. N)+(1/2)*A0; Ff := unapply(S, t) end proc;

f := proc (t) options operator, arrow; piecewise(t < .13*2.6 and 0 <= t, 100*t/(.13*2.6), .13*2.6 <= t and t < 2.6, 100, 2.6 <= t and t < 2.6*1.1, 0) end proc;

sigma := f(t);
a := 0;
b := 1.1*2.6;
s1 := unapply((Fourierf(sigma, a, b, 500))(t)/uw0, t);

s2 := unapply((Fourierf(sigma, a, b, 500))(t)/ua0, t);
A1 := (2*n+1)^2*Pi^2*(C3+1+sqrt(4*C1*C2*C3+C3^2-2*C3+1))/(8*C1*C2-8);
A2 := (2*n+1)^2*Pi^2*(C3+1-sqrt(4*C1*C2*C3+C3^2-2*C3+1))/(8*C1*C2-8);
g := -C2*Cww*(diff(s1(x), `$`(x, 2)))+Caa*(diff(s2(x), `$`(x, 2))+(n+1/2)^2*Pi^2*(diff(s2(x), x)));
f1 := -(1/2)*(n+1/2)^2*Pi^2*sqrt(4*C1*C2*C3+C3^2-2*C3+1)+C2*Cww*((D@@1)(s1))(0)-Caa*((D@@1)(s2))(0)+(n+1/2)^2*Pi^2*(C2-(1/2)*C3+1/2);

CN := ((2*(int(exp(-A1*x)*g, x = 0 .. t)-f1))*exp(A1*t)-(2*(int(exp(-A2*x)*g, x = 0 .. t)-f1))*exp(A2*t))/((n+1/2)^3*Pi^3*sqrt(4*C1*C2*C3+C3^2-2*C3+1));
ua := sum(CN*sin((n+1/2)*Pi*z), n = 0 .. 100);

 

 

I want to solve one equation with one variable and the variable is also in definite integral delimiter. When trying fsolve, I get the error:

"Error, (in fsolve) Can't handle expressions with typed procedures"

code

Here is worksheet.mw

How can I obtain solution with method other from simple manual testing Te values?

Dear All

I have started exploring Lie Algebra package in Maple 18 and it wonderful experience for me. But as I am in learning stage so I feel little difficulty to understand even its basic enviroment.

I am trying to fing quotient algebra for Normalizer of certain element W1 in Lie algebra and I don't how to do it. I have expected answer for quotient of Normlizer but don't know to obtain it. Please see following details:

 

with(DifferentialGeometry):with(LieAlgebras):``

L1 := _DG([["LieAlgebra", Alg1, [6]], [[[1, 3, 1], -1], [[1, 6, 2], -1], [[2, 3, 2], -1], [[2, 4, 1], 1], [[2, 5, 2], 1], [[4, 5, 4], -1], [[4, 6, 3], -1], [[4, 6, 5], -2], [[5, 6, 6], -1]]])

_DG([["LieAlgebra", Alg1, [6]], [[[1, 3, 1], -1], [[1, 6, 2], -1], [[2, 3, 2], -1], [[2, 4, 1], 1], [[2, 5, 2], 1], [[4, 5, 4], -1], [[4, 6, 3], -1], [[4, 6, 5], -2], [[5, 6, 6], -1]]])

(1)

DGsetup(L1)

`Lie algebra: Alg1`

(2)
Alg1 > 

MultiplicationTable("LieTable")

"[[[,`| `,e1,e2,e3,e4,e5,e6],[,-`---`,-`---`,-`---`,-`---`,-`---`,-`---`,-`---`],[e1,`| `,0,0,_DG([["vector",Alg1,[]],[[[1],-1]]]),0,0,_DG([["vector",Alg1,[]],[[[2],-1]]])],[e2,`| `,0,0,_DG([["vector",Alg1,[]],[[[2],-1]]]),_DG([["vector",Alg1,[]],[[[1],1]]]),_DG([["vector",Alg1,[]],[[[2],1]]]),0],[e3,`| `,_DG([["vector",Alg1,[]],[[[1],1]]]),_DG([["vector",Alg1,[]],[[[2],1]]]),0,0,0,0],[e4,`| `,0,_DG([["vector",Alg1,[]],[[[1],-1]]]),0,0,_DG([["vector",Alg1,[]],[[[4],-1]]]),_DG([["vector",Alg1,[]],[[[3],-1],[[5],-2]]])],[e5,`| `,0,_DG([["vector",Alg1,[]],[[[2],-1]]]),0,_DG([["vector",Alg1,[]],[[[4],1]]]),0,_DG([["vector",Alg1,[]],[[[6],-1]]])],[e6,`| `,_DG([["vector",Alg1,[]],[[[2],1]]]),0,0,_DG([["vector",Alg1,[]],[[[3],1],[[5],2]]]),_DG([["vector",Alg1,[]],[[[6],1]]]),0]]]"

(3)
Alg1 > 

W1 := [a*e3+e5]

[a*_DG([["vector", Alg1, []], [[[3], 1]]])+_DG([["vector", Alg1, []], [[[5], 1]]])]

(4)
Alg1 > 

Nor[W1] := SubalgebraNormalizer(W1)

[_DG([["vector", Alg1, []], [[[5], 1]]]), _DG([["vector", Alg1, []], [[[3], 1]]])]

(5)

How one can find Quotient alegebra "(Nor[W1])/(W1)....???`? ``The expected answer is {e3}.`"

I am trying verify 4th 2-dimensional subalgebra results given in research artcle by Coggeshall and Meyer-ter-Vehn (See pp. 3592 in article).

Download [670]_Normalizer_in_Abstract_Lie_Algebra.mw

Regards

I have tried to perform the examples given in the help section for DataSet retrival.  I cannot get Maple 2016 to access the internet available databases.  It does not return any outside of PC resources, like Maple 2015 did, on search items. Is there a setup item that I am missing or is there something amiss in Maple 2016.

This is the Error that I am getting: "Error, (in DataSets:-Search) invalid input: find_count expects its 1st argument, lst, to be of type list(nonnegint), but received [FAIL["total_count"], 0]. "

I was able to run this example in Maple 2105.  The example is the "Average Global Temperature"

 

Thanks

Bill Tolrud

I need to do this with a sequence of a large number of elements but here is my question with a sequence of fewer elements.

a:={10,11,-13,9,20,74,10}:

I want to check each element of the sequence if it is negative. And if any element is negative I want to replace with 0 (or do something else). I tried the following code but it didn't work. 

for k from 1 to 7 do
  if (a[k]<0) then subs(a[k]=0, a) end if:
end do;

Please help me to figure it out. 

@ecterrab 


hello dear,

was working with tensor package using debever formalism in maple v release 5 and got this problem, 
Error, (in factor) expecting a polynomial over an algebraic number field. would u tell me how to deal with this error in maple v release 5. aprl12.mws
thanks,
suresh

Hi,

can you please help me with the usage of applyrule? I have the following problem that I cannot isolate. I have a rule that I want to apply, but instead of applying the rule to the expression, the rule seems to be applied to itself. In an isolated worksheet everything is fine:

restart;

rule:=abs(''a''::algebraic)^2=''a''^2;

abs('a'::algebraic)^2 = 'a'^2

(1)

 

myexp:=abs(548.477146186283171377723+radius_motor*q_mot_vec_2(t)-l_wire_0[2])^2

abs(548.477146186283171377723+radius_motor*q_mot_vec_2(t)-l_wire_0[2])^2

(2)

applyrule(rule,myexp);

(548.477146186283171377723+radius_motor*q_mot_vec_2(t)-l_wire_0[2])^2

(3)

rule

abs(a::algebraic)^2 = a^2

(4)

 


Download applyrule.mw

What happens when I try to use this rule in my script is this:

restart;

#read "some_long_script.mpl":

rule:=abs(''a''::algebraic)^2=''a''^2;

abs('a'::algebraic)^2 = 'a'^2

(1)

applyrule(rule,abs(x)^2)

abs(x)^2

(2)

rule

a::algebraic^2 = a^2

(3)

 

>
 

I want to clarify, that the script that is read before applying those rules does not apply a similar rule. Also the variables rule and x were free. Can you please help me to locate the problem?

Thanks!

Honigmelone

Hello everyone!

I want to generate an lower triangular matrix. Please see the attachment and help me. I am waiting your quick response. 

Help.mw

The result I am looking for is Re[Sqrt[x + I*y]] = 1/2 Sqrt[2 (SQrt[x^2+y^2]+x)]. How can I get it?

Hey,

at some point in my maple calculations I have to read some symbolic constants because otherwise the expressions become to big. All my constants are in a range 1e-3 to 1e6 or something. No matter how exact I calculate my result always has some Numbers in the range of <1e-20 (how small they actually are varies with Digits) together with numbers 1e-3..1e6. I presume those 1e-20 are just zeros. Can I somehow tell maple to forget/drop very small numbers and assume them all to be zero?

Thanks!

Honigmelone

Hey all,

I want to symbolically differentiate a function and recalculate the result later. Here is what I have tried so far:


restart;

myexp:=dfdb+sthlong

dfdb+sthlong

(1)

b:=<b1(t),b2(t)>;

b := Vector(2, {(1) = b1(t), (2) = b2(t)})

(2)

dfdb:=Physics[diff]~(f(b),b)

dfdb := Vector(2, {(1) = (D(f))(Vector(2, {(1) = b1(t), (2) = b2(t)})), (2) = (D(f))(Vector(2, {(1) = b1(t), (2) = b2(t)}))})

(3)

f:=b->b(1)^2+b(2)

proc (b) options operator, arrow; b(1)^2+b(2) end proc

(4)

eval(myexp);  #actual result

 

 

sthlong+(Vector(2, {(1) = (D(f))(Vector(2, {(1) = b1(t), (2) = b2(t)})), (2) = (D(f))(Vector(2, {(1) = b1(t), (2) = b2(t)}))}))

(5)

dfdb:=Physics[diff]~(f(b),b):

eval(myexp); #expected result

sthlong+(Vector(2, {(1) = 2*b1(t), (2) = 1}))

(6)

 


Download physics_diff.mw

I wonder if this is even possible, or if I missunderstand something. Can you please help me?

 

Thanks

 

Honigmelone

In Maple 17, I had

evalf(5^1.25, 30);
7.476743906

evalf(5^(5/4), 30);
7.47674390610610270955949497070

evalf(evalf(5^1.25, 30)-evalf(5^(5/4), 30), 30);
-1.0610270955949497070 *10^(-10)

I would expect the two results to be the same. 

I am using Maple 17 and windows 7 operating system. 

Is there a reason that  evalf(5^1.25, 30) will not compute 30 decimal places?

 

 

How to generate a random normal distribution of points around the point [3,15] for example?

Hello everyone

I have a problem with the code below in maple:

> restart;
> f := signum(a*cos(t+b)+sin(t+c));
> res := int(f, t = 0 .. 2*Pi);
                       2 Pi signum(a cos(b) + sin(c))
> a := 0.01; b := 0; c := 0;
> res; int(f, t = 0 .. 2*Pi);
                                    2 Pi
                                     0.

As you can see, results are not consistent with one another...

If I set a := 0.01; b := 1.35; c := 4.4; It is even worse, the computation of int(f, t = 0 .. 2*Pi) lasts more than 10 minutes (when I interrupt computation)

I tested it in Maple 12 and Maple 2015 and I get exactly the same results. I also replaced signum with csgn and I get the same problem.

I really need your help!!

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