Maple Questions and Posts

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Help me to export data of 3d plot

Download export.mw

Dear,

 

Could you please help me with the following problem? 

I have a list, say, L:= [2,3,4,5]; 

and I need to find the position of several of its elements. However, when a apply the BinarySearch command I get a wrong return. For example, element >= 5:  BinarySearch(L, 5, `>=`);  

Maple returns 0

Element = 4: BinarySearch(L, 4, `=`); 

Maple returns 0

Element < 3: BinarySearch(L, 3, `<`); 

Maple returns 2. 

Obviusly, I'm doing something wrong. Could you please tell me what it is?

Many thanks for your help.

 

Maple 2020 offers many improvements motivated and driven by our users.

Every single update in a new release has a story behind it. It might be a new function that a customer wants, a response to some feedback about usability, or an itch that a developer needs to scratch.

I’ll end this post with a story about acoustic guitars and how they drove improvements in signal and audio processing. But first, here are some of my personal favorites from Maple 2020.

Graph theory is a big focus of Maple 2020. The new features include more control over visualization, additional special graphs, new analysis functions, and even an interactive layout tool.

I’m particularly enamoured by these:

  • We’ve introduced new centrality measures - these help you determine the most influential vertices, based on their connections to other vertices
  • You now have more control over the styling of graphs – for example, you can vary the size or color of a nodebased on its centrality

I’ve used these two new features to identify the most influential MaplePrimes users. Get the worksheet here.

@Carl Love – looks like you’re the biggest mover and shaker on MaplePrimes (well, according to the eigenvector centrality of the MaplePrimes interaction graph).

We’ve also started using graph theory elsewhere in Maple. For example, you can generate static call graph to visualize dependencies between procedures calls in a procedure

You now get smoother edges for 3d surfaces with non-numeric values. Just look at the difference between Maple 2019 and 2020 for this plot.

Printing and PDF export has gotten a whole lot better.  We’ve put a lot of work into the proper handling of plots, tables, and interactive components, so the results look better than before.

For example, plots now maintain their aspect ratio when printed. So your carefully constructed psychrometric chart will not be squashed and stretched when exported to a PDF.

We’ve overhauled the start page to give it a cleaner, less cluttered look – this is much more digestible for new users (experienced users might find the new look attractive as well!). There’s a link to the Maple Portal, and an updated Maple Fundamentals guide that helps new users learn the product.

We’ve also linked to a guide that helps you choose between Document and Worksheet, and a link to a new movie.

New messages also guide new users away from some very common mistakes. For example, students often type “e” when referring to the exponential constant – a warning now appears if that is detected

We’re always tweaking existing functions to make them faster. For example, you can now compute the natural logarithm of large integers much more quickly and with less memory.

This calculation is about 50 times faster in Maple 2020 than in prior versions:

Many of our educators have asked for this – the linear algebra tutorials now return step by step solutions to the main document, so you have a record of what you did after the tutor is closed.

Continuing with this theme, the Student:-LinearAlgebra context menu features several new linear algebra visualizations to the Student:-LinearAlgebra Context Menu. This, for example, is an eigenvector plot.

Maple can now numerically evaluate various integral transforms.

The numerical inversion of integral transforms has application in many branches of science and engineering.

Maple is the world’s best tool for the symbolic solution of ODEs and PDEs, and in each release we push the boundary back further.

For example, Maple 2020 has improved tools for find hypergeometric solutions for linear PDEs.

This might seem like a minor improvement that’s barely worth mentions, but it’s one I now use all the time! You can now reorder worksheet tabs just by clicking and dragging.

The Hough transform lets you detect straight lines and line segments in images.

Hough transforms are widely used in automatic lane detection systems for autonomous driving. You can even detect the straight lines on a Sudoku grid!

The Physics package is always a pleasure to write about because it's something we do far better than the competition.

The new explore option in TensorArray combines two themes in Maple - Physics and interactive components. It's an intuitive solution to the real problem of viewing the contents of higher dimensional tensorial expressions.

There are many more updates to Physics in Maple 2020, including a completely rewritten FeynmanDiagrams command.

The Quantum Chemistry Toolbox has been updated with more analysis tools and curriculum material.

There’s more teaching content for general chemistry.

Among the many new analysis functions, you can now visualize transition orbitals.

I promised you a story about acoustic guitars and Maple 2020, didn’t I?

I often start a perfectly innocuous conversation about Maple that descends into several weeks of intense, feverish work.

The work is partly for me, but mostly for my colleagues. They don’t like me for that.

That conversation usually happens on a Friday afternoon, when we’re least prepared for it. On the plus side, this often means a user has planted a germ of an idea for a new feature or improvement, and we just have to will it into existence.

One Friday afternoon last year, I was speaking to a user about acoustic guitars. He wanted to synthetically generate guitar chords with reverb, and export the sound to a 32-bit Wave file. All of this, in Maple.

This started a chain of events that that involved least-square filters, frequency response curves, convolution, Karplus-Strong string synthesis and more. We’ll package up the results of this work, and hand it over to you – our users – over the next one or two releases.

Let me tell you what made it into Maple 2020.

Start by listening to this:

It’s a guitar chord played twice, the second time with reverb, both generated with Maple.

The reverb was simulated with convolving the artificially generated guitar chord with an impulse response. I had a choice of convolution functions in the SignalProcessing and AudioTools packages.

Both gave the same results, but we found that SignalProcessing:-Convolution was much faster than its AudioTools counterpart.

There’s no reason for the speed difference, so R&D modified AudioTools:-Convolution to leverage SignalProcessing:-Convolution for the instances for which their options are compatible. In this application, AudioTools:-Convolution is 25 times faster in Maple 2020 than Maple 2019!

We also discovered that the underlying library we use for the SignalProcessing package (the Intel IPP) gives two options for convolution that we were previously not using; a method which use an explicit formula and a “fast” method that uses FFTs. We modified SignalProcessing:-Convolution to accept both options (previously, we used just one of the methods),

That’s the story behind two new features in Maple 2020. Look at the entirety of what’s new in this release – there’s a tale for each new feature. I’d love to tell you more, but I’d run out of ink before I finish.

To read about everything that’s new in Maple 2020, go to the new features page.

Does anyone have any ideas on why this integral (third equation) is taking so long to solve/plot? Are there any hints on how to speed up the process?

I'm running Maple 2019.1, and it was chugging away for about 5 minutes before I pulled the plug.

If I have 2.14 & 10 or 2.14 & 20 as my plot arguments, it takes about 3 s. After 20, it just doesn't want to work.

P1:=(r,R)->(2/Pi)*(arccos(r/(2*R))-(r/(2*R))*sqrt(1-(r/(2*R))^2))

J0:=(r,shk)-> BesselJ(0, 2*Pi*r*shk);

Jhk:=(s,shk,R)-> evalf((1/s)*Int(P1(r,R)*J0(r,shk)*sin(2*Pi*r*s), r=0..2*R));

plot(Jhk(s,2.14,38), s=0..5)

I'm attempting to use Maple to study Maxwell's Equations, but as a newbie to Maple, I quickly became stuck :-)

For some context, this link shows how it is possible to accomplish this using Mathematica:

https://www.wolfram.com/mathematica/new-in-10/inactive-objects/study-maxwells-equations.html

This is how I have attempted the same in Maple:

Maxwell's Equations

NULL

Initialise

 

restart

with(Physics[Vectors])

[`&x`, `+`, `.`, ChangeBasis, ChangeCoordinates, Component, Curl, DirectionalDiff, Divergence, Gradient, Identify, Laplacian, Nabla, Norm, Setup, diff]

(1.1)

Setup(mathematicalnotation = true)

[mathematicalnotation = true]

(1.2)

``

````

Maxwell's Equations

 

Maxwell_1 := Curl(E__field_(x, y, z, t)) = -(diff(B__flux_(x, y, z, t), t))

Physics:-Vectors:-Curl(E__field_(x, y, z, t)) = -(diff(B__flux_(x, y, z, t), t))

(2.1)

Maxwell_2 := Curl(H__field_(x, y, z, t)) = diff(D__flux_(x, y, z, t), t)

Physics:-Vectors:-Curl(H__field_(x, y, z, t)) = diff(D__flux_(x, y, z, t), t)

(2.2)

Maxwell_3 := Divergence(D__flux_(x, y, z, t)) = 0

Physics:-Vectors:-Divergence(D__flux_(x, y, z, t)) = 0

(2.3)

Maxwell_4 := Divergence(B__flux_(x, y, z, t)) = 0

Physics:-Vectors:-Divergence(B__flux_(x, y, z, t)) = 0

(2.4)

``

``

Constitutive Relations

 

Eq_1 := D__flux_(x, y, z, t) = epsilon*E__field_(x, y, z, t)

D__flux_(x, y, z, t) = varepsilon*E__field_(x, y, z, t)

(3.1)

Eq_2 := B__flux_(x, y, z, t) = mu*H__field_(x, y, z, t)

B__flux_(x, y, z, t) = mu*H__field_(x, y, z, t)

(3.2)

``

``

Solution

 

We need to get the Curl of H, to take the Curl of both side of Maxwell_1:

Curl(Maxwell_1)

Physics:-Vectors:-Curl(Physics:-Vectors:-Curl(E__field_(x, y, z, t))) = -Physics:-Vectors:-Curl(diff(B__flux_(x, y, z, t), t))

(4.1)

Now substitute B for H:

subs(Eq_2, %)

Physics:-Vectors:-Curl(Physics:-Vectors:-Curl(E__field_(x, y, z, t))) = -Physics:-Vectors:-Curl(diff(mu*H__field_(x, y, z, t), t))

(4.2)

OK, we manage to get Curl of H, so now we need to substitute the Curl of H with an expression in D.

subs(Maxwell_2, %)

Physics:-Vectors:-Curl(Physics:-Vectors:-Curl(E__field_(x, y, z, t))) = -mu*Physics:-Vectors:-Curl(diff(H__field_(x, y, z, t), t))

(4.3)

Well that didn't work, so try to seperate the Curl of H so that we can substitute for D.``

collect(%, Curl(H__field_(x, y, z, t)))

Physics:-Vectors:-Curl(Physics:-Vectors:-Curl(E__field_(x, y, z, t))) = -mu*Physics:-Vectors:-Curl(diff(H__field_(x, y, z, t), t))

(4.4)

simplify(%)

Physics:-Vectors:-Curl(Physics:-Vectors:-Curl(E__field_(x, y, z, t))) = -mu*Physics:-Vectors:-Curl(diff(H__field_(x, y, z, t), t))

(4.5)

collect(%, Curl(H__field_(x, y, z, t)))

Physics:-Vectors:-Curl(Physics:-Vectors:-Curl(E__field_(x, y, z, t))) = -mu*Physics:-Vectors:-Curl(diff(H__field_(x, y, z, t), t))

(4.6)

``

``

``

SortProducts(%, [H__field_(x, y, z, t)], totheleft)

SortProducts(Physics:-Vectors:-Curl(Physics:-Vectors:-Curl(E__field_(x, y, z, t))) = -mu*Physics:-Vectors:-Curl(diff(H__field_(x, y, z, t), t)), [H__field_(x, y, z, t)], totheleft)

(4.7)

``

``

``

``

``

isolate(%, H__field_(x, y, z, t))

SortProducts(Physics:-Vectors:-Curl(Physics:-Vectors:-Curl(E__field_(x, y, z, t))) = -mu*Physics:-Vectors:-Curl(diff(H__field_(x, y, z, t), t)), [H__field_(x, y, z, t)], totheleft) = 0

(4.8)

``

``

``

``

``

``

NULL

NULL

``

 

I need to be able to rearrange equation 4.3 so that I can substitute for Curl of H using Maxwell_2.  Any suggestions would be gratefully received!
 

Download Maxwells_Equations.mw

Hi forum

I got a problem:

When i use these lines:

with(plots);
implicitplot(y = a*x + b, x = -10 .. 10, y = -10 .. 10, axis = [gridlines = [10, color = blue]]);



The vertical axis dosent stretches as far as i want it to.

The 'Axis Gridlines Properties' match the plot.

But the 'Axis Properties' dosent:


I can change the 'range' manually, by checking off the 'use data extend' box.
- But i need to use these plotting commands, very often.
Is it possible to write something in the plot-function, so i dosent need to do these corrections manually, every time i plot something?

Thank you in advance
Dan

Write a procedure approxInt that takes in a function f, a number of intervals
N, a left endpoint a, and a right endpoint b. Given these data, the procedure should split the
interval [a, b] into N subintervals and use the function f to estimate the area under the curve
using 
(a) Left endpoints,
(b) Right endpoints,
(c) Midpoints, and
(d) Trapezoids.

 Write another procedure called compareApproxInt that does the following:
  (a) Takes as inputs the function f, the endpoints a and b, and the number of subintervals N.
  (b) Calls the procedure approxInt in order to estimate the area under the curve of f(x) with
       N subintervals, with the four different approximations methods.
  (c) Returns four sentences:
       Using        , the approximate area under f is        . This method has a margin of error of         .

Test compareApproxInt with the functions 
 f1(x) = x
 f2(x) = x^2 ,
 f3(x) = x^3 - 4 · x^2 , and
 f4(x) = e^x ,
 each on the interval [-1, 1], with 10 subintervals.

 

Is it possible to put 2D math text on Text Area or Label components?

Like greek alpha, beta, or more complex expressions.

Hello, 

I am doing a regression analysis, but some of my model says: Warning, model is not of full rank. Can anyone help what to do with that? 

Rok := Vector([2013, 2014, 2015, 2016, 2017, 2018], datatype = float);

TrzbyCelkemEmco := Vector([1028155, 1134120, 1004758, 929584, 995716, 1152042], datatype = float);

KubickaTrzby = Statistics:-PolynomialFit(3, Rok, TrzbyCelkemEmco, x);


 

 

Thank you :)  

 

 

 

Hello.

Is there a way to make maple sum variables with a index definition?

I want to sum this

`X__1`:=4.83

`X__2`:=4.33

`X__3`:=4.66

sum(X[i], i = 1 .. 3)

But it result with X[1] + X[2] + X[3] instead of 13.81

 

Hi,

Is there anyway to solve this equation for x(t) analytically in Maple?

m * diff(diff(x(t),t), t) = - m * A * sin(2*pi*f*t) - piecewise( abs(x) < x__max, 0, abs(x) >= x__max, -k*(abs(x)-x__max)*Sgn(x)) - diff(x(t), t);

m, x_max, f, A, and k are constant parameters.

Thanks,

Baharm31

 

In the help file the permitted declartions for the second argument of the Escape command from the StringTools package are html,regexp and xml, to not specify one, which as far as I can tell instructs maple to take all characters as plain text with no escape characters.

Is this the complete list of options for the form when using the escape command?

Or is it possible to custom build escape rules?

 

Sorry to bother you with another very basic question.

This very simple example shows that Maple gives the first value that is defined back, ignoring changes further down the definition chain.

Could someone explain why, and if there is a way to always get the updated values?


 

m := Matrix(2, 2, {(1, 1) = 1, (1, 2) = 3, (2, 1) = 2, (2, 2) = 4})

Matrix(%id = 18446745932232999750)

(1)

a := 1

1

(2)

b := m[a, 1]

1

(3)

a := 2

2

(4)

b

1

(5)

m[2, 1]

2

(6)

``


 

Download VariableIndex.mw

Hi,

I've been trying to replicate an example described in a book called "Quantum Mechanics Using Maple" by M. Horbatsch, but at the end, when I'm using fsolve it returns 0. instead .500 .

I'm using Maple 18, but I think this book was written using Maple V. I don't know if the syntax changes are causing this. I'm very new to maple. Here's my worksheet (qm_maple_-_periodic_potentials.mw) and book section (qm_maple_periodic.pdf). Thanks in advance!

I was wondering if there was any way to reassign the "||" operator to calculate parallel resistors?

like this:

R1 || R2 = (1/R1+1/R2)^(-1)

 

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