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achreftabet

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4 years, 65 days
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thanks a lot...

achreftabet 60
May 26 2023
0 0

i hace another question how do i calculate this sum in maple 18  thinks

thanks a lot...

achreftabet 60
April 29 2023
0 0

@acer 

thanks alot 

I am very grateful to you

Thank you for your help...

achreftabet 60
April 29 2023
0 0

@acer 

Thank you for your help  

please i have other question if you can halp me 

How can be written this system of eqautions such that the variables (r,Z,U,V,W,S) depends to theta 

thanks Download problem_1.mw

Thanks...

achreftabet 60
June 22 2022
0 0

@acer

hello thanks for your help

Please how do i find this reslut in maple 

@Carl Love  All information in thi...

achreftabet 60
June 11 2021
0 0

@Carl Love 

All information in this papers

how Classification of equilibrium point...

achreftabet 60
January 20 2021
0 0

@Kitonum 

please 

how  Classification of equilibrium points in R^3

maple...

achreftabet 60
August 11 2020
0 0

@Scot Gould 

i did not understand this step

maple...

achreftabet 60
August 11 2020
0 0

@Kitonum 

hi

What is the difference between Maple 18 and Maple 2018

thank you...

achreftabet 60
August 10 2020
0 0

@Scot Gould 

thank you for answering my questions about the sum
I have another problem in the compilations

Sum_vs_Add_(1).mw
 

> 

restart; randomize():

Define S and test it:

 

> 

S := n -> sum( sum( a[i, j]*x^i*y^j, j = 0..n-i), i=0..n);

proc (n) options operator, arrow; sum(sum(a[i, j]*x^i*y^j, j = 0 .. n-i), i = 0 .. n) end proc

 (1)
> 

S(2);

x^2*a[2, 0]+x*y*a[1, 1]+y^2*a[0, 2]+x*a[1, 0]+y*a[0, 1]+a[0, 0]

 (2)

Define A and test it:

> 

A := n -> add( add( a[i,j]*x^i*y^j, j=0..n-i), i=0..n);

proc (n) options operator, arrow; add(add(a[i, j]*x^i*y^j, j = 0 .. n-i), i = 0 .. n) end proc

 (3)
> 

A(2);

x^2*a[2, 0]+x*y*a[1, 1]+y^2*a[0, 2]+x*a[1, 0]+y*a[0, 1]+a[0, 0]

 (4)


Assign values random values to the elements  in the array `a`. (i have problem)

> 

N := 10:
a := Array(0..N, 0..N, (i,j)->rand(-1.0..1.0)())

Warning, inserted missing semicolon at end of statement

  

Error, invalid input: rand expects its 1st argument, r, to be of type {posint, integer .. integer}, but received -1.0 .. 1.0

  

 

Problem: te

sting S with n = 2.

> 

S(2);

x^2*a[2, 0]+x*y*a[1, 1]+y^2*a[0, 2]+x*a[1, 0]+y*a[0, 1]+a[0, 0]

 (5)

Hmm, no longer symbolic.

 

As opposed to A:

> 

A(2);

x^2*a[2, 0]+x*y*a[1, 1]+y^2*a[0, 2]+x*a[1, 0]+y*a[0, 1]+a[0, 0]

 (6)

S can't be plotted even if the function is delayed:

> 

plot3d( 'S(10)', x=0..1, y=0..1)

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

  

 

But this does work.

> 

newS := (x,y,n) -> sum( sum( a[i, j]*x^i*y^j, j = 0..n-i), i=0..n);

proc (x, y, n) options operator, arrow; sum(sum(a[i, j]*x^i*y^j, j = 0 .. n-i), i = 0 .. n) end proc

 (7)
> 

plot3d('newS(x,y,10)', x=0..1, y=0..1);

 

A behaves as a I would expect.

> 

plot3d(A(10), x=0..1, y=0..1)

 
> 

 


 you can calculate this sum by this program

-2 + x - xy + x2 + 2 y2
 

Download Sum_vs_Add_(1).mw

 

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