## unable to plot LegendreQ...

I do not know what I am doing wrong. I am trying to plot each of the solutions to an ODE. One of the solutions Maple gives is  LegendreQ((1/2)*sqrt(5)-1/2, x) and the other is LegendreP((1/2)*sqrt(5)-1/2, x)

Maple can plot the  LegendreP, but gives an error plotting LegendreQ((1/2)*sqrt(5)-1/2, x)

```ode:=(1-x^2)*diff(y(x),x\$2)-2*x*diff(y(x),x)+y(x)=0:
sol:=dsolve(ode,y(x));
```

sol := y(x) = _C1*LegendreP((1/2)*sqrt(5)-1/2, x)+_C2*LegendreQ((1/2)*sqrt(5)-1/2, x)

Now when I do

`plot(LegendreQ((1/2)*sqrt(5)-1/2, x),x=-1..1);`

Maple says

Warning, unable to evaluate the function to numeric values in the region; see the plotting command's help page to ensure the calling sequence is correct

Why is that? I tried x=-0.5..1 and x=0.5..1 and keep getting same error message. It works ok for

`plot(LegendreP((1/2)*sqrt(5)-1/2, x),x=-1..1);`

Mathematica can plot both with no problem.

## Calculate integral?...

int(exp(-sec(t))*cos(t)/(-1/4+sin(t)^2), t = 0 .. (1/2)*Pi, CauchyPrincipalValue = true, numeric = true);

Returns unevaluated for me.

```I tried all the methods in HELP documentation and I failed.
Integral is singular at point 1/4.

```

Thank you.

## How to find suitable initial condition...

Hello my friends

I have a problem with initial condition for below system of differential equation

sys := {6*(diff(a(t), t))^2+12*a(t)*(diff(a(t), t\$2))-3*a(t)^2*phi(t)^(-2*c)*sqrt(1-alpha*(diff(phi(t), t))^2), 2*c*a(t)^3*phi(t)^(-2*c-1)*sqrt(1-alpha*(diff(phi(t), t))^2)-3*alpha*a(t)^2*phi(t)^(-2*c)*(diff(a(t), t))*(diff(phi(t), t))/sqrt(1-alpha*(diff(phi(t), t))^2)-alpha*a(t)^3*phi(t)^(-2*c)*(diff(phi(t), t\$2))/sqrt(1-alpha*(diff(phi(t), t))^2)+2*c*alpha*a(t)^3*phi(t)^(-2*c-1)*(diff(phi(t), t))^2/sqrt(1-alpha*(diff(phi(t), t))^2)-alpha^2*a(t)^3*phi(t)^(-2*c)*(diff(phi(t), t))^2*(diff(phi(t), t\$2))/(1-alpha*(diff(phi(t), t))^2)^(3/2), R(t) = 6*((diff(a(t), t))^2/a(t)^2+(diff(a(t), t\$2))/a(t)), W(t) = -phi(t)^(-2*c)*sqrt(1-alpha*(diff(phi(t), t))^2)/(1/a(t)^3+a(t)^3+phi(t)^(-2*c)/sqrt(1-alpha*(diff(phi(t), t))^2))}

I set {c,alpha}={1,1} but initial conditon is problem ... since I got the following message from maple to illustrate diagrams of W(t), a(t) and even phi(t)

Warning, cannot evaluate the solution past the initial point, problem may be complex, initially singular or improperly set up

with the best regard

## Controlling plot range in a parametric 3D plot...

Hi,

I would like to control the extents of my 3D parametric plot. Increasing the grid creates too many gridlines and I just get a black plot  (and I still don't get the extent in the y-coordinate that I want).

Any suggestions how I might be able to get this plot from -360 to 0 and -20 to 60 completely filled in? (see attached workbook).

Any suggestions on how to control the gridlines?

An idea of what I am trying to do...I want to plot argument(z/(1+z)) vs. argument(z)*180/pi vs. 20*log10(abs(z)) with contours of argument(z/(1+z)) and 20*log10(abs(z/(1+z))
This is a 3D plot of the output phase of a Nichol's Chart (with the output contours of the Nichol's chart).

Thanks.

phaseplot.mw

## Can the procedure be improved for speed....

Can the procedure called Faul be made more efficient/faster? It is very slow for generating large polynomials.

Faulhaber Polynomials Generation

 (1)

OR

 (2)

 (3)

 (4)

 (5)

 (6)

 (7)

 (8)

 (9)

## Plot function as a ratio of two variables ...

I have got the following function:

R = ((n1-n2)/(n1+n2))^2

I would like to plot R as a function of (n1/n2). How can I do this in maple?

## Problems with Export command...

Hello everyone,

I have a project that uses several machines to make a computation. I wrote a package (called here "package") with procedures, "proc".  I wrote several .mpl files structured as:

W:= Read("file1.mpl"):    #I wrote a procedure to read and assign to a variable. This is not the problem.

Export("output.mpl", proc(W));

The situation is as follows: in all but one of my machines, this works fine, and proc(W) is exported correctly. However, in this ugly duckling (which is running the GUI version of Maple18), maple prints as an output, in blue:

Export("output.mpl",...)

and in place of ... it gives the answer expected. But it does not export automatically. I can, of course, manually correct this, but this is not optimal. Moreover, if the output is too big, there will be display issues.

Help? Any light is appreciated, thanks.

Marcelo

PS: I do not expect an answer for the PS; but I also do not know how to make my package "official", in the sense that I always read the .mpl file with all the procedures. Is there a way to call it like the LinearAlgebra and so on and use the package:-proc syntax?

## STEM Education: Application generator in Maple

Maple 2018

Due to the mechanistic process of our students and little creativity in analysis in schools and universities to be professionally trained is that STEM education appears (science, technology, engineering and mathematics) is a new model that is being considered in other countries and with very slow step in our city. In this work the methods with STEM will be visualized but using computational tools provided by Maplesoft which is a company that leads online education for adolescents and adults in the current market. In Spanish.

ECI_UNT_2018.pdf

ECI_UNT_2018.mw

Lenin Araujo Castillo

## Maple and Microsoft Visual C++ 2015 redistributabl...

What wouldn't work in Maple 2018 if I removed the Microsoft Visual C++ 2015 redistributable?  I have older versions of the C++ redistributable packages (ie 2013).  I hadn't noticed anything unusual when I initially removed it but maybe there's something that's affected in Maple?  Code generation package routines maybe?  What commands in Maple would be affected?

Reason is, I'm getting errors with another software and re-installing the 2015 C++ redistributable isn't installing properly.  So I'm just hoping there's no issues using Maple without the C++ 2015 redistributable being installed properly.

## how i can pdsolve this equation...

how i can pdsolve this equation

Doc186.pdf

## basic questions on MapleCloud packages and how to ...

These are some basic questions on using packages from Maple Cloud. I only used it once or twice so far.

When I click on the "cloud" icon, on top right corner of the menu, I see on the left panel "Math apps" then below it "packages" and then below it is says "installed".

When I click on "installed", I see one package that I installed sometime ago.

1) How does one uninstall a package listed in the "installed" list? I see no option to do this.

2) How does one know if the "installed" package needs to be updated or not? And if so, how does one updated it?

3) In the "packages" list, I see "physics Updates".  Now,  I did install this earlier (1-2 weeks ago). Then why is it not listed also under the "installed" list? And how does one know if they have installed a package that shows in the "packages" list?

There is no marker or anything there to tell one they have installed it or not.  Is one supposed to go look in the "installed" list to manually check if they installed it or not?

4)What happens if one install a package/app they have installed before. Will the new package overwrite the older version automatically?

5) It seems packages installed go to some temporary folder. Is there a way to configure it, so that all packages installed go to some other user defined folder. This way, if one moves to a new PC or such, they do not lose all the packages they have installed?

It seems these basic functionalities are missing: 1. option to uninstall a package. 2. Marker of some kind to tell one if they installed something listed in the "packages" list. 3. Marker to tell one if a package they have installed needs to be updated if there is a newer version on the cloud.

Only options I see are: Install, view, share link and search. That is all. All the above also applies to "Math apps".

Using Maple 2018 on windows.

## Maple returning "_SELECTION" instead of a real out...

I've been using Maple 2018 only a few days now, was mostly using Maple 2016 and never had any issues with returning an output (at least one that wasnt my fault), but with 2018 I've seen a few times where a simple task would return an output of "__SELECTION" and then my input. No idea what this is or why its happening and all I really need to know is how to prevent it from happening. If its something with my preferences or settings that needs to be addressed, thats fine, but otherwise this is getting to be a real pain. See attached

## Problem with the Variables list in Maple 2018?...

Occasionally I use the Variables palette to inspect some variables after a run. In Maple2018 it seems every Vector or Array returns something like "Empty variable structure" or similar. I never saw this in prior versions of Maple.

A bug? Or am I missing something??

M.D.

## Recognizing Handwritten Digits with Machine Learni...

by: Maple 2018

To demonstrate Maple 2018’s new Python connectivity, we wanted to integrate a large Python library. The result is the DeepLearning package - this offers an interface to a subset of the Tensorflow framework for machine learning.

I thought I’d share an application that demonstrates how the DeepLearning package can be used to recognize the numbers in images of handwritten digits.

The application employs a very small subset of the MNIST database of handwritten digits. Here’s a sample image for the digit 0.

This image can be represented as a matrix of pixel intensities.

The application generates weights for each digit by training a two-layer neural network using multinomial logistic regression. When visualized, the weights for each digit might look like this.

Let’s say that we’re comparing an image of a handwritten digit to the weights for the digit 0. If a pixel with a high intensity lands in

• an intensely red area, the evidence is high that the number in the image is 0
• an intensely blue area, the evidence is low that the number in the image is 0

While this explanation is technically simplistic, the application offers more detail.

Get the application here

## Maple won't open...

Hi

Maple 2017.3 wont open, when I launch it. I've tried updating Maple, updating Java, updating my graphic driver and of course restarting my computer. It just keeps on the loading launcher at a completely empty loading bar.