Hello guys, 

I have a probelm with computing an integral by maple. I dont know why maple cannot compute.

integral.mw

Thank you for your attention

Best

I do not understand why Maple can simplify this expression below when told that n is integer and also positive using a "," to separate the assumptions, but does simpify the same expression when using "and" to build the assumptions.

Here is an example

restart;
result:=int(x*cos(n*Pi/5*x),x=0..5)
simplify(result) assuming n::integer and n>0

But this works

simplify(result) assuming n::integer, n>0

What are the semantic differences between writing assuming "n::integer and n>0" and "n::integer,n>0" ? I thought these would be the same, but clearly they are not.

Maple 2019.1 on windows.

1/0;
Error, numeric exception: division by zero
lastexception;
            0, "numeric exception: division by zero"
lastexception; # ???
            Typesetting:-Typeset, "invalid input: %1 expects %2 arguments, but received %3", type, 2, 3

So, printing lastexception produces a new error!
When typesetting=standard, it's OK.

Hello my Maple friends! :)
I was wondering if there is any command in Maple that can help me find the equation of a surface from it´s parametric form and the other way around, a parametric form from a surface equation!
For example, if
x :=(s, t) -> s cos(t)
y :=(s, t) -> s sin(t)
z :=(s, t) -> s^2

then S: x^2+y^2=z

Thank you for your help.
English is not my mother tongue; please excuse any errors on my part.

I have two data sets (time series) that appear to have similar profiles and am looking to find a way to establish a correlation measure. The linear (Pearson) coefficient is around 0.89, but since this particular function is nonlinear, can anyone suggest a method or routine that can be used to obtain this correlation?

Thank you!

Correlation.mw

Hello, would you please help with this problem

 I need to solve the system using polynomial coefficients

thank you 

Download dsolve.mwdsolve.mw

Download rand.mw

Download SHAFEEG2.mwSHAFEEG2.mw

Hey.. AoA,
How to combine a specific rows of two different Matrix?

Hi, I have a procedure named f1. In it, it calls another procedure f couple of times. procedure f does not have recursive calls implemented.

I have no idea what caused the error. Could anyone give a hint?

Thanks a million in advance,

Best,

Jie

I like Maple the most for calculation of difficult parts. But when it comes to display, I am ignorant and do not know how to command the maple for showing me what is visible in the document.

I attach herewith my document which shows in print view only top half of the sketch. What should I do to show all three figures in the portrait page.
(Here below, after uploading it is shown alright, but in the print preview it is not showing!!).

I want to convert the doc to pdf. Therefore, in the doc preview itself it should be complete.

Thanks for help.

Ramakrishnan V
 

Download sketchesNotComing_in_full.mw

Hello,

do not work well and U functions are not replaced with series form.

Please see equation 5.

Also, How me can differential with respect to the constant Amnr], Bmnr], Cmnr] as shown in   attached figure?

For Differentiation I need a

Diff.pdf

Hello! I have a Maple sheet that is functional in some versions of Maple but not others. It works perfectly in Maple 18 (which is the version with which it was written), but when running it in Maple 2019, I see the following error:

• "Error, (in Matrix) cannot determine if this expression is true or false: Distance(Vector[row](3, {(1) = 0., (2) = 1.313799622, (3) = 0}), Vector[row](3, {(1) = 0., (2) = -1.313799622, (3) = 0})) < 99999999999999999999/100000000000000000000"

And believe that it is related to the following lines of code:

• R := Matrix(N, (i, j) -> Distance(coords[i], coords[j]) ;
• S := Matrix(N, (i, j) -> if i = j then 1 elif R[i, j] < 3 then (1+C*R[i, j]+(2/5)*C^2*R[i, j]^2+(1/15)*C^3*R[i, j]^3)*exp(-C*R[i, j]) else 0 end if)

It seems as if it cannot compute a distance between two points (as given in the form of two vectors). I have imported the Student:-Precalculus package, along with ArrayTools and LinearAlgebra, at the start of the sheet, but am wondering if there is an issue with this package in other versions of Maple. The full sheet can be provided if more information is needed, but I'm pretty sure that portion is the problem. Any help would be greatly appreciated.

Sheet: testsheet.mw

I can use ApproximateInt for the integral?

approximate_int
 

Download approximate_int.mw

Hi everybody and thank you all in advance.

This is my question. Suppose I have a list of lists like this:

[[1,2,3],[7,8,9],[13,12,11]]

I want to select all 3^rd element from the list of lists and get:

[3,9,11]

Another example:

[1, [2, 3], [4, [5, 6], 7], [8, 3], 9] and select the first element from the list of lists and get:

[1, 2, 4, 8, 9]

Additionally suppose I want to sort a list of lists but base on the 3^rd element of every sublist. Example:

From this list:

[[1,2,3],[7,8,2],[13,12,1]] sorted by the  3^rd element I would get:

[[13,12,1], [7,8,2], [1,2,3]]