Unanswered Questions

This page lists MaplePrimes questions that have not yet received an answer

Every time I open Maple it has the invitation to Login in the top right-hand corner.  I would like to sign in but have had quite a bit of trouble doing that.  I have a user name and password with Maplesoft web store and the same for MaplePrimes.  Should either of these work to log in? 

When doing

item:=x;
res:=remove(has,item,x);

Maple returns, as expected

But when item is not a single symbol, say sin(x) or diff(y(x),x), then it no longer returns ()

item:=diff(y(x),x);
res:=remove(has,item,diff(y(x),x));

It does not return () but it now returns the input itself, as if it was not removed.

Why is that, and how to make it return () also on composite expression?  I tried flatten and inplace option. Otherwise, I will have to do a special test before. 

The strange thing is that it works on 

item:=2*diff(y(x),x);
res:=remove(has,item,diff(y(x),x));

Now it returns as expected. So now it did remove diff(y(x),x). But it does not remove it when it is on its own. I assume this is by design. But it is not intuitive to the user. One would expect it to work same way on removing `x` or `sin(x)` or `diff(y(x),x)`


 

with(plots); with(LinearAlgebra)

NULL

NULL

NULL

couples := [5, 0], [6, 0], [6, 3], [10, 3], [7, 5], [9, 5], [7, 7], [8, 7], [5.5, 9], [3, 7], [4, 7], [2, 5], [4, 5], [1, 3], [5, 3]

Points := Matrix([[5, 6, 6, 10, 7, 9, 7, 8, 5.5, 3, 4, 2, 4, 1, 5], [0, 0, 3, 3, 5, 5, 7, 7, 9, 7, 7, 5, 5, 3, 3]])

NULL

Homothety

 

W := Matrix(2, 2, {(1, 1) = (1/60)*k, (1, 2) = 0, (2, 1) = 0, (2, 2) = (1/60)*k})NULLNULL``NULLNULL

Rotation on x axis

 

NULL

X := Matrix(2, 2, {(1, 1) = cos((1/90)*Pi*k), (1, 2) = sin((1/90)*Pi*k), (2, 1) = sin((1/90)*Pi*k), (2, 2) = -cos((1/90)*Pi*k)})````NULLNULL

Rotation of angle k

 

Y := Matrix(2, 2, {(1, 1) = cos((1/180)*Pi*k), (1, 2) = -sin((1/180)*Pi*k), (2, 1) = sin((1/180)*Pi*k), (2, 2) = cos((1/180)*Pi*k)})NULLNULLNULL

``

n := Multiply(Y, Multiply(X, Multiply(W, Points)))

_rtable[18446746437110297774]

(3.1)

NouvCouples := seq([n[1, i], n[2, i]], i = 1 .. 15)

Sapin := animate(polygonplot, [[NouvCouples], color = "ForestGreen"], k = 0 .. 180)

 

 

NULL

Neige

 

PointsNeige := seq([-30+i, 30-(1/2)*j*sin(i+j)], i = 0 .. 60); neige := animate(pointplot, [[PointsNeige], color = black], j = 0 .. 60, view = [-30 .. 30, 0 .. 30])

 

NULL

display([Sapin, neige], scaling = constrained)

 

NULL

NULL


 

Download Homework.mw

 

Hi, i need some help for a homework.

Here is the statement

You must first animate a series of linear transformations on the polygon formed by the following couples: [5, 0], [6., 0], [6, 3], [10, 3], [7, 5], [9, 5], [7, 7], [8, 7], [5.5, 9], [3, 7], [4, 7], [2, 5], [4, 5], [1, 3], [5, 3] It will be necessary to make, at the same time, a rotation around a line making an angle k with the axis of x, a rotation of an angle k and a scaling of variable ratio (but equal to 3 at the end animation). The k animation parameter should range from 0 to 180. I suggest you use the color green for your polygon. Then you will need to create a second animation by entering these command lines: SnowPoints: = seq ([- 30 + i, 30 - j / 2 * sin (i + j)], i = 0 .. 60): snow: = animate (pointplot, [[PointsNeige], color = black], j = 0 .. 60, view = [-30 .. 30, 0 .. 30]) : Finally, you will have to roll both animations at the same time.

The GIF shows the results that I should get according to my teacher

Thanks for the help !

Error occurred running sample test.java (at new EngineCallBackDefault()):

# A fatal error has been detected by the Java Runtime Environment:
#
#  EXCEPTION_ACCESS_VIOLATION (0xc0000005) at pc=0x00007ffd66e7345a, pid=1740, tid=7716
#
# JRE version: Java(TM) SE Runtime Environment (11.0.1+13) (build 11.0.1+13-LTS)
# Java VM: Java HotSpot(TM) 64-Bit Server VM (11.0.1+13-LTS, mixed mode, tiered, compressed oops, g1 gc, windows-amd64)
# Problematic frame:
# C  [maplec.dll+0x345a]
#
# No core dump will be written. Minidumps are not enabled by default on client versions of Windows
#
# If you would like to submit a bug report, please visit:
#   http://bugreport.java.com/bugreport/crash.jsp
# The crash happened outside the Java Virtual Machine in native code.

Dear all

I compute the solution of first order nonlinear ode, supplied to initial condition.

The code is written, the exact solution is derived.

 plot the solution in a small interval like (0,1/5) I see that there is no difference between exact and semi-analytical soluton.

But, If I plot the solution in other interval like (0,1) or (0,2), It is noticed that the semi-analytical solution is different to the exact solution. 
Thansk you in advance for your help 

test3.mw

Apparently a colon within a string causes some issues when generating a XMLElement.

Didn't find anything in Maple Help about that though.

with(XMLTools)

dummy := "NS-EN 1995-1-1, part 1-1, Section 6"

"NS-EN 1995-1-1, part 1-1, Section 6"

(1)

XMLElement(dummy)

_XML_Element(_XML_ElementType("NS-EN 1995-1-1, part 1-1, Section 6"), [], [])

(2)

dummy1 := "NS-EN 1995-1-1, part 1-1, Section 6: Ultimate"

"NS-EN 1995-1-1, part 1-1, Section 6: Ultimate"

(3)

XMLElement(dummy1)

Error, (in XMLTools:-XMLElement) element tag name `NS-EN 1995-1-1, part 1-1, Section 6: Ultimate' contains the namespace prefix `NS-EN 1995-1-1, part 1-1, Section 6', but there is no `xmlns' attribute

 

NULL

Download xmlns.mw

Good day everyone,

I have problem-solving this system of equations using Iterative Projection Theorem. Anyone with a better explanations please.

The equation is as stated below. 

 

Solve this set of equations using the iterative projection theorem.

(x1 - 2)2 + (2x22 - 6)2 - 5 = 0

(x12 - 4)2 + (x2 - 10)2 - 39 = 0

Take the provisional values of  x1 and x2 as x01 = 5, x02 = 4, 

Thank you in anticipation

Good day everyone, please I'm soliciting help on how to solve PDE in Maple. I know how to solve ODE but I don't know how to go about PDE. The problem I want to solve is attached as an attachment. If epsilon is zero, then the problem reduces to ODE which can easily be solved, but epsilon is not supposed to be zero. please I need your help, thank you in anticipation.

PDE.pdf

How to change the distance (spacing) between 2D Input cells and 2D Output cells so that this procedure can be inserted into a style sheet and thus applied to multiple documents?

Regards

Oliveira

Hi Maple Users,

Microsoft is enticing me to upgrade to Windows 11 from 10 for free. I am a bit hesitant because I don't know if Maple 2021 will continue working as well as in Windows 10. Does anyone have any thoughts or wisdom to share.

Thank you.

How do i get to the 2nd line for a multiple problem? 

I want to calculate the effective value of Time Quanta in seconds of electron on 1 S Orbital using a new PDE equation.

 See ElectronFlux.docx and ElectronFlux.pdf for details.

I have 2 variants in ElectronFlux.mw but did not reach the final value in seconds.

The document is constantly changing and uses an equation that, for a distance of a few radii Bohr rB is equivalent to the Schrodinger equation. We particularized for the 1 S Orbital of Hydrogen atom thus the velocity o the electron is c/137; (V=a*c=c/137);

eq1 := 2*m*(E + ec^2/r)*f(r, t)/h^2 + R*diff(f(r, t), r $ 2)/r - diff(f(r, t), t $ 2)/(a^2*c^2) = 0 with condition:iv1 := f(R, t) = 0, D[1](f)(0, t) = R, f(rb, t) = 0, D[2](g)(rb, t) = a*c;

I am gladly willing to talk with other people about the idea and the calculus to fulfill the effective value that in my opinion should be Tce = rB/C = 1.765*10-19 sec.

Thanks in advance!

electronFluxT.mw

ElectronFlux.docx

ElectroFluxT.pdf

Hi,

I am generating several random weighted graphs using the following code:

with(GraphTheory):
with(RandomGraphs):
G:=RandomGraph(10,20,connected):
G1:=AssignEdgeWeights(G,5..25):
DrawGraph(G1,showlabels=true,stylesheet=[edgecolor=blue,weightfont = [times,bold,11]])

By default weight labels appear to be positioned at the midpoint of each edge. Is there a way to change that positioning?

Thanks!

have table like table(symmetric, [() = x]) from other code not mine, strange syntax

how to extract x from table thanks

I want to calculate the Noether Symmetries from the Lagrangian. Is there any built-in Maple cammad to  where i just put the lagrangian and get the determining PDEs and calculate the Noether Symmetries?

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