Hi,

I just upgraded to Maple 2021 and started getting strange results - similar calculations seemed to work in Maple 2020.

I am looking at correlated bivariate normal distributions. When doing a fully symbolic verification of the normalization, I get an incorrect result of infinity. I also get strange results when integrating over a circular region, but the normalization seemed to be a very elementary calculation.

Maybe someone can check this make sure I'm not losing my marbles. I've attached a worksheet.

Thanks.

Bivariate_Gaussian.mw

hi, do you know how can we plot analogy situation from this post:

https://mathematica.stackexchange.com/questions/100051/dynamic-epicycles/100108#100108

I really like simplicity and beauty of the idea from:

https://www.mapleprimes.com/posts/206167-Procedures-For-Two-Animations

and I wonder if it would be possible to add a third rolling circle similarly not including such long code from first page.

thanks in advance

Is there a reason that an angle theta from zero to pi/2 (0 to 90 deg) returns as invalid for an animation range?  I am trying to rotate a vector 2D for visualization.  This is build-up towards a 3d rotating vector in an animation.  

Here is the code: theta is the arrow tip rotation's location via cos(theta), sin(theta) coordinates in a 2D vector.

animate(arrow, [<cos(theta), sin(theta)>, width = [0.05, relative], view = [-1 .. 2, -1 .. 2], color = "blue"], theta = 0 .. Pi/2)

ErrorMessage:  

Error, (in plots/animate) 0 = 0 .. (1/2)*Pi  is an invalid animation range

Thanks In Advance,

Bill

How can this expression sorted in order of the symbol "y"? I want the terms with y locate at the beginnig.

Download sort.mw

As the title, who can help me fix the problem like this

theta:= diff(arctan(y,x)):

W:= piecewise(

         theta>-Pi/2 and theta< -Pi/2+10, 1+A+B*cos(theta),

         theta>-Pi/2+10 and theta< Pi/2-10. 1-A+B*cos(thea)); 

there always plotout the undefined when acrtan(y,x)=Pi/2,

How can I ignore this undefined or define another value for W when acrtan(y,x)=Pi/2

    Dear Fellows
Hoped everything is fine with you. I plotted some contours for a flow model and i want to generate its dat file. Please help me in this regard. Thanks

Attached is a worksheet containing a simple assignment that gives an "illegal use of an object as a name" error. I created the superscripted name in the following way.

1)  type b.

2) click on the Insert|Typesetting|Superscript  item in the insert menu.

3) enter 1 at the cursor in the superscript position.

4)  the result is a name b with superscript 1, but this symbol does not constitute a valid name for an assignment.

Download errorws.mw

How Would I fix that?

Hi 

I forgot how to display the output ar an array i.e. (r,u(r)) (table of data)

I am sure i will find answers here.

a:=-0.1:alpha:=0.2:

dsys:={diff(u(r),r,r)+((1-alpha)/r+r^(alpha-2))*diff(u(r),r)=a};

res1:=dsolve(dsys union {u(0.05)=0,u(1)=0},numeric);

How we can see steps of Laplace transform calculation?

In a thesis by Md. Mohsin Ali at the University of Ontario, he says that ifactor uses multiple threads and presents a graph of measured results.

I ran ifactor with a 100 digit input and do not see mserver using multiple cores in top.  I do see mserver using 100% of a single core.

Am I missing something?

It would be nice to save various animated Maple images from into GIF images, but without the coordinates and the axes. THe same question in anoehr way: Can we plot the original function without any axes or coordinates?

Thank you!

mapleatha

ifactor(1522605027922533360535618378132637429718068114961380688657908494580122963258952897654000350692006139);

kilobytes used=921, alloc=1200, time=0.09
kilobytes used=1325, alloc=5296, time=0.13

...

kilobytes used=107733, alloc=9228, time=6.64

Process Maple segmentation fault (core dumped)

No matter what I do from the keyboard, a core dump is not a reasonable response.

This worksheet animates stereographic projection of a grid on a sphere onto the plane the sphere sits on.

Is there a way to display matching colors in corresponding cells in the two grids?

Stereographic_projection.mw