## How to convert an imported data to Vector?...

A very big data was imported by me through

data := Import("http://fs3.fex.net/get/245716150875/11071260/data.txt");
"3.0994584798345
22.889020258043
....

26.082759642081
42.911810680717
6.4578968130322"



I need to convert it to Vector/Array. Now its type is "string":

whattype(data);
string


Here is my unsuccessful attempt:

convert(data,Vector);
Error, invalid input: convert/Vector expects its 1st argument, V, to be of type {Array, Matrix, Vector, array, sequential}, but received 3.0994584798345
22.889020258043
....

data.mw

## Simplified form of equation/function ...

I am new user of Maple, couldn’t find solution for my problem in the last two days therefore I would like to turn to your community with my question. I am trying to replicate the calculations from a study to be sure about my understanding of the topic.

I cannot simplify the final equation even though the variables with their values are given. A screenshot and the file are attached, that might make easier to understand my problem.

I know what the solution should be. I cannot simplify/replace the values in the equation to get a simpler form; [(D0 - d1c - R)/ 2d1)]+c

Thank you if you have the time to help.

Joint_Pricing_Sol_.maple

## Solving equation with two reststricted variables...

How do I check if there are any solutions to this equation:
1/(u+v)^2+4*u*v-1=0
where both u and v are real numbers larger than 0.

## Select remove in partitition...

Hi

How can I remove a subset containing a number from a partition?

eg S := [seq(2..5)]

P:=combinat:-setpartition(S, 2);

[[[2, 3], [4, 5]], [[2, 4], [3, 5]], [[2, 5], [3, 4]]]

I want to remove any partition involving 5

leaving

[[[2, 3]], [[2, 4]], [[3, 4]]]

i tried

remove(has,P,5)

## Incomplete worksheet...

I'm studying for an exam and earlier today I was working in my Maple sheet. I saved it as usual and no .bak file was in the directory afterwards. When I now later in the day tried to open it, I got the pop up message:
"There were problems during the loading process. your worksheet may be incomplete" and half of the content is missing.

I've searched on google and tried to solve it myself, unfortunately without any luck.

I would really appreciate any help.

Best regards

## Maybe a limitation to DocumentTools :-RunWorkshee...

Hi everybody,

I am used to using  the DocumentTools :-RunWorksheet command and I am confronted with the following problem :

• My worksheet is deemed to generate a plot in a png file
> plotsetup(png, plotoutput=MyFile, …)
> plot( …)

But MyFile is not created

• Thinking that the mw file launched by  DocumentTools :-RunWorksheet is seen as a procedure, I have thought that print(plot(…)) would fix the issue.
Unfortunately the png file is still not created (same behavior with a jpeg file)

I know that  DocumentTools :-RunWorksheet is “experimental” but I wonder if I am doing something wrong or if DocumentTools :-RunWorksheet simply does not support plots ?

## Using the Poincare-Dulac Thm to develop an iterati...

proc:=changecoords([x,y],logrithmic);
dsolvediff(x,t):=Matrix([[ 1 , 0],
[ 0 , i ]])x+Vector[column]([ x^i ,
0]);
x:=y+h(y);
for i from 2 to 10;
solve;
end do;

endproc;

MakeIteration := proc( expr::algebraic, x::name )
local iteration := diff(x,t)=Matrix([[ 1 , 0 ],
[ 0 , i]])x+Vector[column]([ x^i ,
0]),x:=y+h(y);
for i from 2 to 10 ;
end do ;
unapply(iteration, x);
endproc;
Error, missing operator or ;

Hi , I would like to solve nonlinear equation by using maple,but I wander how I can write it since there is a change of veriable bysubstiuting the value of y in the diifferenitat . Iactually coudnot write the equation sine it contains differential ,matrix and vector . do Ihave to use dalembertian?

best regards

## solve with units...

Hello,

how can I tell Maple that "u" has the dimension of volts?

## How Do I Display Fast Parametric Surface with Smoo...

Dear MaplePrimes team,

For display a beautiful parametric surface with hole (or pierced surface), unfortunately unlike CAD (computer-aided design) tool, Maple requires a large grid number. Therefore the computing is too long and requires huge RAM only with grid of [500,500] on a modern computer.

Fig. 1: For a complex surface such an aircraft fuselage here, Needs high grid, therefore, the compilation is too long with modern computer (Intel Core i7, 2.4 GHz CPU, 16 GB RAM). If displays supplementary windows holes on fuselage, the software may bug when the RAM is full.

Question 1:

In matter of low cost computation, do you have better solution to create a fast surface with smooth hole from given a parametric surface equation S(x,y) and given any convex/concave-closed parametric curve C(t) that is projected on surface S(x,y)?

Fig. 2: These surfaces are been created in Maple 2016 from given initial parametric surface equation and curve projected on the surface. But requires huge grid, huge RAM, and long time to get smooth hole when free CAD tools are fast and low RAM.

Question 2:

Because I noted that the Maple’s view option renderers smooth edges of any surface. My question is: Is it possible to use the internal structure of display/view used by Maple to apply at free boundaries? I think it will be possible to create many class of view, for examples: cylindrical sector, spherical sector views or more rather to be limited with conventional cubic view. And thus, I think it will be possible to create own smooth hole or multiple-hole on surface and get smooth pierced surface.

I know that almost of technicians/engineers will recommend me to use a CAD tool to create surface with hole. But the objective here is to keep purely a mathematical mind and work with exact equations (analytic equations).

On a free CAD tool, even the complex holes are created very fast only with low RAM. Why not on Maple?

Best.

Guy.

## fopen does not work...

The command

fd:=fopen("C:/temp/",'WRITE');

suddenly does not work. I keep getting a 'permission denied' error message. I haven't had to write anything to a file for a while so do you think the recent windows update screwed something up? In fact, I can't seem to write any file anywhere. It was working weeks ago. My apology if this ends up being a lame question. :)

## setting up constraints...

Sirs.

Probably a brain fade, but I cant seem to code what i want.

Tour2:=[[[1, 2, 3, 4]], [[1, 2], [1, 3, 4]], [[1, 3], [1, 2, 4]], [[1, 4], [1, 2, 3]], [[1, 2], [1, 3], [1, 4]]];M:=nops(Tour2):

 (1)

interface(rtablesize=M):
maxEnt:=max([seq(nops(Tour2[i]),i=1..M)]):
Tours_Distances := Matrix
( maxEnt,
M,
[ seq
( [ seq
( if( numelems(Tour2[i])>=j,
d[i]*x[op(Tour2[i,j])]<=K,
0
),
i=1..M
)
],
j=1..maxEnt
)
]
);

 (2)

convert( (2), 'list', 'nested' );

 (3)

But what I want is:

d[1]*x[1,2]+d[2]*x[2,3]+d[3]*x[3,4]<=K,d[1]*x[1,2]<=K,d[1]*x[1,3]+d[3]*x[3,4]<=K;      #.....etc.

 (4)

## Problem by plotting triangle in the pyramid...

Hello guys,

I´ve a little bit problem by plotting an pyramid with an triangle in it. When I want to display both

parts, in the drawing the left and the right part and the top of the pyramid is missing. What is the problem ???
Abituraufgabe_2016_B2_Pyramide.mw

Thanks

## Maple too slow for the calculation of product of s...

I am trying to evaluate the following function J(n,phi) which can be used to find out a*b(-A*J(3,Pi/6)+B*J(6,Pi/6)) but it takes too much of time whereas mathematica takes much less time for the same. The maple file is attached. Hope my problem get solve. Thank you

restart;

r := 2.8749; a := 0.7747; b := 0.3812; A := 17.4; B := 29000; R := 5.4813; Z := 2;

J := proc (n, phi) options operator, arrow; 8*Pi^(3/2)*r*R*(sum((2*r*R)^(2*i)*pochhammer((1/2)*n, i)*pochhammer((1/2)*n+1/2, i)*(sum((-1)^j*cos(phi)^(2*j)*(sum((2*r*cos(phi))^(2.*l)*pochhammer(n+2*i, 2*l)*hypergeom([2*j+2*l+1, .5], [2*j+2*l+1.5], -1)*(.5*Beta(l+.5, n+2*i+l-.5)-sin(arctan(-Z/sqrt(R^2+r^2)))^(2*l+1)*hypergeom([-n-2*i-l+1.5, l+.5], [l+1.5], sin(arctan(-Z/sqrt(R^2+r^2)))^2)/(2*l+1))/(factorial(2*l)*pochhammer(2*j+2*l+1, .5)*(R^2+r^2)^(n+2*i+l-.5)), l = 0 .. 100))/(factorial(i-j)*factorial(j)), j = 0 .. i))/factorial(i), i = 0 .. 100)) end proc;

evalf(a*b*(-A*J(3, (1/6)*Pi)+B*J(6, (1/6)*Pi)));
JJ.mw

## Maple and Geometry Expressions software...

Hi, is anyone using the Geometry Expressions software together with Maple? I've found about this software on forum and installed a free demo version. It is using symbolic geometry, which I haven't been able to find this feature on other software, and can work very well with Maple, but unfortunatelly, my demo version doesn't work properly, and their oficial website http://saltire.com/ has lots of errors 404 page not found. I have requested support, but have had no answer so far. I was so happy finding this software, but now I am thinking maybe wasting my time. If you are using it, or maybe think it would be good to give it a go, please let me know if it is working for you. A particular feature which is not working for me is 'creating angles'. Thank you.

## Multiplying numerator and denominator by the same ...

I have a fraction where I would like to isolate a certain term by multiplying the numerator and denominator by the same term.

My fraction is:

outOverin := R[2]*s^2*L[2]*C[2]/(s^4*C[2]*C[3]*L[2]*L[3]*R[2]+s^3*C[2]*L[2]*L[3]+s^2*C[2]*L[2]*R[2]+s^2*C[3]*L[2]*R[2]+s^2*C[3]*L[3]*R[2]+s*L[2]+s*L[3]+R[2])

I would like to take out a term so that I have s4 on its own in the denominator, so I try the following:

outOverin*(1/(C[2]*C[3]*L[2]*L[3]*R[2])*(C[2]*C[3]*L[2]*L[3]*R[2]))

But Maple does not take out the term like I would like it to, and I get the same fraction as before

How can I isolate s4 in the denominator?

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