Given a list say

A=[1, 2,6,7,9,10,15,17]

If I give a=3 and b=5

I should get a sublist containing all elements from 3 to 5 in index

That is [6,7,9] sublist of the above list

Kind help 

I am writing a program that produces ball and stick images of raphs in 3D - hence in a box.  It works find (well, it takes a while) for graphs of a certain size, but when I want to double the length / width / height of the box, it produces an error message: "Plot internal error: unrecognized option Dag in Plot".  Of course, I have no option Dag in my code.  Any ideas?

Hi there.

I found some strange behavior of int function in document with using of Physics package in Maple 2021 in comparison with Maple 2020:

kerr.mw

Please look at that.

Thank you.

Here's another basic question in programming, sorry about that.

This little program does a loop over a table which was just created, and thus empty. As far as I can see the for - do loop goes through the loop at least once.

Is there a way to change the program, so that it doesn't go through the contents of the loop at all?

Download table_and_loop.mw

Int(UxUxy+UxxUy, x)=UxUy

How can I do this?

Is there a means of getting Maple to detect and print the operating system which it is being run on? Searching for this topic is awkward as it returns page after page of troubleshooting guides on how to get Maple running on different operating systems.

Conventionally in Bash I would use something like: echo $(uname)

Any idea how I can get the number of elements in an exprseq after a SearchAll command?

numelems apparently is not the right function.

Download numelems.mw

Show that x-2 is a factor of p(x)=x^3+3x^2-4x-12

I)determine all the linear factors of p(x)

ii)what are the zeros of y=p(x)

iii)sketch function y=p(x)

Hi there.

I would like to get advice about most elegant and effective ways of building animated plots (sequnces of plots) of two kinds:

1. Coordinates of point on some background curve. So each plot in sequence contain constant background curve and single point that moving from plot to plot;

2. Line of points from some array. So i-th plot in sequence draw line that build on i (1..i) points from array.

I want to demonstrate these animated plots on some example - Kepler problem (point moving on ellipse):

ell.mw

But I don't think that my code is effective.

Thank you.

Suppose I have one or more equations in the variables  , ..., , where each equation is a linear combination of rational functions in  , ..., . For example, one equation might be:

Any such equation can be turned into a polynomial by multiplying both sides by the products of all the denominators. In the example, this would be .

My question is whether there is a Maple command to do this automatically? This would be helpful as I have a large number of equations.

I seem to remember that the save command had a bug about truncating big integers, and it was solved.
But now (Maple 2020) it is present again.
I wonder whether it is present in Maple 2021 too.

restart;
fname:="d:/tmp/ftest.mpl":
f:=proc(n)
  local i,k;
  for i to n do f(i):=parse(cat("", seq(k mod 10, k=1..10*i))) od;
  f(n);
end:

f(80):
length(%);  # 800, ok
save f, fname;
f:='f':
#restart;
read fname:
f(80):
length(%);  # 100  ???

In Maple 2021

restart;
B:=sqrt( (-4*u^(1/3)+1)*u^(4/3));
A:=1/(-12*u+3*u^(2/3)-3*B);
res:=int(A,u);
simplify(res)

This is one of the integrals, that in Maple 2020 did not handle. In Maple 2020, it gives this

restart;
B:=sqrt( (-4*u^(1/3)+1)*u^(4/3));
A:=1/( -12*u+ 3*u^(2/3)-3*B);
res:=int(A,u);

The difference is that in Maple 2021 int is able to solve this (but gives very long output which I will not post here). The problem is now simplify() gives an error on the result. I was trying to see if possible to obtain the same small result as Mathematica's after simplifying. Here is Mathematica's result

ClearAll[u];
B = Sqrt[(-4*u^(1/3) + 1)*u^(4/3)];
A = 1/(-12*u + 3*u^(2/3) - 3*B);
res = Integrate[A, u]

It is good that Maple can solve this integral, but why simplify gives error on the result? Is there a workaround?

Download QformPost.mw

I read the code in the link below and have some thoughts on drawing the graph.

https://www.mapleprimes.com/questions/216092-Options-For-Graph-Drawing-In-The-GraphTheory

But if we want to change the edge to a curvilinear style, it seems very difficult. We know  PetersenGraph is 1-planar graph.  The following picture is one of  its 1-plane drawing.  That is  also what I want to draw .

PS: A 1-planar graph is a graph that can be drawn in the Euclidean plane in such a way that each edge has at most one crossing point, where it crosses a single additional edge. 

Although I asked a similar question, but it uses too many special curve functions and the method is relatively isolated. Because the cycle graph is too special.  https://www.mapleprimes.com/questions/228987--Can-We-Draw-Curved-Edges-In-The-Graph

I also noticed the optional items of the edge style.  But there are no curves, such as arcs, parabola, etc.

The plot style must be one of line, point, pointline, polygon (patchnogrid), or polygonoutline (patch).  

I am trying to draw a parabola, it seems to be quite difficult. And it completely deviated from the use of graph theory package.

I would like to ask maple if there is a more versatile and simpler way to draw a curve of  graph drawing.

try.mwtry.mw

The above program is too cumbersome and not robust