## OHAM soruce code in Maple for PDEs...

kindly send me OHAM source code in Maple for PDEs. I need it.

## How to list only real solutions when there are oth...

Hello

I have the following set of coefficients

`coef7 := [-1, 2, alpha[1, 2], alpha[2, 6], (17*RootOf(64*_Z^3+80*_Z^2+1104*_Z+561)+17)/(alpha[1, 2]*alpha[2, 6]), -17/alpha[2, 6], -33/(32*RootOf(64*_Z^3+80*_Z^2+1104*_Z+561)), -(163/32+RootOf(64*_Z^3+80*_Z^2+1104*_Z+561)^2+5*RootOf(64*_Z^3+80*_Z^2+1104*_Z+561)*(1/4))/(alpha[1, 2]*alpha[2, 6]), -RootOf(64*_Z^3+80*_Z^2+1104*_Z+561)-5/4, RootOf(64*_Z^3+80*_Z^2+1104*_Z+561)]`

Considering that alpha[1,2] and alpha[2,6] are always real, how can I extract only the real solution from coef7?

Many thanks.

Ed

## How to find index of specific element?...

Hello everyone!

Is it possible to find index of first non-negative or first positive Vector's (or Array's) element with the help of one Maple build-in comand (for example: use something from ArrayTools or ListTools)?

## Which function is good for displaying strings f...

In maple, how to change strings style? Thanks!

In Mathematica , we can choose Style to change strings style.

Style["A", Blue, Italic, 24]

source of the  problem : I make an User Interface.

the color of   "mass "  may consider be changed to  red .

## Why did I get an unterminated loop error again?...

` `
 >
 >
 (1)
 >

Hello everyone. I was trying to code the recurrence relation given in the image below (without taking the mth power):

But, as I run the program, I am getting an "unterminated loop" error. Can someone please point out the mistake(s)?

## Is there any way to write the expression into the ...

Is there any way to write the expression into the ratio of simple determinants? i..e,

## Remove ugly decorations due to units module...

Hi,

How do we remove the module name functions that massively pollute the output after using with(Units[Standard]):

So that I can have something presentable like this :

Thanks!

## How to find a rational function with give real roo...

Dear sir, I request to suggest the method for the following posted question.

How to find a rational function with give real roots 1,2,3  and oblique asymptote y=2-x?

## Minimizing the result of a numerical integral - Op...

Based on an answer to a question posted on MaplePrimes, which I am I able to locate through the search system, but that I know it is recent, I am trying to calculate the parameters of a function which minimizes the result of a numerical integral. The function, f1(x), is well defined. The function f2(x) has two parameters, K and r. The integral of the square of the difference between the two function cannot be solved symbolically. Hence my plan is to use the Minimization function in Optimization to determine the values of K and r.

The attached worksheet includes two examples - a practice example for me to become familiar with using Optimization:-Minimization for an integral and the actual problem I am attempting to solve. Note: it was only through MaplePrimes that I learned the function must be defined through a procedure. Here is what I discovered in my experiments:

* the command to perform the numerical integration requires the small "i" verion of int, not Int, i.e evalf( int( function, limits )), not evalf(Int(..)).  This seems to be inconsistent with the documentation. Can someone explain why it is this way?

* The function must be defined locally. If I try to use a globally defined function, non-numeric results are encountered. Is there a way to integrate a global function?

* For the practice problem, it works as long as I abide by the conditions in the previous 2 bullet points.

* When I try to solve the real problem, which appears to be solvable by eyeballing some graphs (included), the kernal is lost.  This is repeatable for me. Do others experience this problem?

-------------------

Aside: It would be useful if the output of a search in MaplePrimes could be sorted by date.

MaplePrimes_Minimization.mw

## CodeGeneration in C throws Error: Error, (in Print...

Hi, can someone explain me why CodeGeneration in C throws the error : Error, (in Print) improper op or subscript selector ? Interestingly, CodeGeneration in Python or Matlab works. Source code is attached. Thanks in advance!

Membrane Energy

 Define variables Vectors for vertices of current position  =    =  = Vector for vertices of next position  =  =  =

Define Transformation

=

=

Note we have  and if the current triangle is not degenerate, then . As we can pre-compute  we define a new matrix for it:

=

 (1.2.1)

=

 Define Energy

 Gradient and Hessian = t1 = v2n_i[0] - v1n_i[0]; t2 = v2n_i[1] - v1n_i[1]; t3 = v2n_i[2] - v1n_i[2]; t4 = t1 * Vinv_ij[0][0] + t2 * Vinv_ij[1][0] + t3 * Vinv_ij[2][0]; t5 = t1 * Vinv_ij[0][1] + t2 * Vinv_ij[1][1] + t3 * Vinv_ij[2][1]; t6 = t1 * Vinv_ij[0][2] + t2 * Vinv_ij[1][2] + t3 * Vinv_ij[2][2]; t7 = v3n_i[0] - v1n_i[0]; t8 = v3n_i[1] - v1n_i[1]; t9 = v3n_i[2] - v1n_i[2]; t10 = t7 * Vinv_ij[0][0] + t8 * Vinv_ij[1][0] + t9 * Vinv_ij[2][0]; t11 = t7 * Vinv_ij[0][1] + t8 * Vinv_ij[1][1] + t9 * Vinv_ij[2][1]; t12 = t7 * Vinv_ij[0][2] + t8 * Vinv_ij[1][2] + t9 * Vinv_ij[2][2]; t13 = t2 * t9 - t3 * t8; t14 = fabs(t13); t15 = t1 * t9 - t3 * t7; t16 = fabs(t15); t17 = t1 * t8 - t2 * t7; t18 = fabs(t17); t19 = pow(t14, 0.2e1) + pow(t16, 0.2e1) + pow(t18, 0.2e1); t20 = pow(t19, -0.5e1 / 0.4e1); t19 = t19 * t20; t21 = Vinv_ij[0][0] * t13; t22 = Vinv_ij[1][0] * t15; t23 = Vinv_ij[2][0] * t17; t24 = (t23 + t21 - t22) * t19; t25 = -v2n_i[2] + v3n_i[2]; t26 = fabs(t15) / t15; t27 = -v2n_i[1] + v3n_i[1]; t28 = fabs(t17) / t17; t21 = t23 + t21 - t22; t22 = (t16 * t25 * t26 + t18 * t27 * t28) * t20; t23 = 0.1e1 / 0.2e1; t29 = Vinv_ij[0][1] * t13; t30 = Vinv_ij[1][1] * t15; t31 = Vinv_ij[2][1] * t17; t32 = (t31 + t29 - t30) * t19; t29 = t31 + t29 - t30; t30 = Vinv_ij[0][2] * t13; t15 = Vinv_ij[1][2] * t15; t17 = Vinv_ij[2][2] * t17; t31 = (t17 + t30 - t15) * t19; t15 = t17 + t30 - t15; t17 = t6 + t12; t30 = t5 + t11; t33 = t4 + t10; t13 = fabs(t13) / t13; t34 = -v2n_i[0] + v3n_i[0]; t35 = (t14 * t25 * t13 - t18 * t34 * t28) * t20; t35 = t17 * Vinv_ij[1][2] - t24 * (t23 * t35 * t21 - t19 * (t25 * Vinv_ij[0][0] - t34 * Vinv_ij[2][0])) + t30 * Vinv_ij[1][1] - t31 * (t23 * t35 * t15 - t19 * (t25 * Vinv_ij[0][2] - t34 * Vinv_ij[2][2])) - t32 * (t23 * t35 * t29 - t19 * (t25 * Vinv_ij[0][1] - t34 * Vinv_ij[2][1])) + t33 * Vinv_ij[1][0]; t36 = (t14 * t27 * t13 + t16 * t34 * t26) * t20; t34 = Vinv_ij[2][2] * t17 - t24 * (-t23 * t36 * t21 + t19 * (t27 * Vinv_ij[0][0] - t34 * Vinv_ij[1][0])) + t30 * Vinv_ij[2][1] - t31 * (-t23 * t36 * t15 + t19 * (t27 * Vinv_ij[0][2] - t34 * Vinv_ij[1][2])) - t32 * (-t23 * t36 * t29 + t19 * (t27 * Vinv_ij[0][1] - t34 * Vinv_ij[1][1])) + t33 * Vinv_ij[2][0]; t36 = (t16 * t9 * t26 + t18 * t8 * t28) * t20; t36 = t24 * (-t23 * t36 * t21 - t19 * (-t8 * Vinv_ij[2][0] + t9 * Vinv_ij[1][0])) + t31 * (-t23 * t36 * t15 - t19 * (-t8 * Vinv_ij[2][2] + t9 * Vinv_ij[1][2])) + t32 * (-t23 * t36 * t29 - t19 * (-t8 * Vinv_ij[2][1] + t9 * Vinv_ij[1][1])) + t4 * Vinv_ij[0][0] + t5 * Vinv_ij[0][1] + t6 * Vinv_ij[0][2]; t37 = (t14 * t9 * t13 - t18 * t7 * t28) * t20; t9 = t24 * (-t23 * t37 * t21 + t19 * (-t7 * Vinv_ij[2][0] + t9 * Vinv_ij[0][0])) + t31 * (-t15 * t23 * t37 + t19 * (-t7 * Vinv_ij[2][2] + t9 * Vinv_ij[0][2])) + t32 * (-t23 * t29 * t37 + t19 * (-t7 * Vinv_ij[2][1] + t9 * Vinv_ij[0][1])) + t4 * Vinv_ij[1][0] + t5 * Vinv_ij[1][1] + t6 * Vinv_ij[1][2]; t37 = (t14 * t8 * t13 + t16 * t7 * t26) * t20; t4 = t24 * (t23 * t37 * t21 - t19 * (-t7 * Vinv_ij[1][0] + t8 * Vinv_ij[0][0])) + t31 * (t15 * t23 * t37 - t19 * (-t7 * Vinv_ij[1][2] + t8 * Vinv_ij[0][2])) + t32 * (t23 * t29 * t37 - t19 * (-t7 * Vinv_ij[1][1] + t8 * Vinv_ij[0][1])) + t4 * Vinv_ij[2][0] + t5 * Vinv_ij[2][1] + t6 * Vinv_ij[2][2]; t5 = (t16 * t3 * t26 + t18 * t2 * t28) * t20; t5 = t10 * Vinv_ij[0][0] + t11 * Vinv_ij[0][1] + t12 * Vinv_ij[0][2] + t24 * (t21 * t23 * t5 + t19 * (-t2 * Vinv_ij[2][0] + t3 * Vinv_ij[1][0])) + t31 * (t15 * t23 * t5 + t19 * (-t2 * Vinv_ij[2][2] + t3 * Vinv_ij[1][2])) + t32 * (t23 * t29 * t5 + t19 * (-t2 * Vinv_ij[2][1] + t3 * Vinv_ij[1][1])); t6 = (-t18 * t1 * t28 + t14 * t3 * t13) * t20; t3 = t10 * Vinv_ij[1][0] + t11 * Vinv_ij[1][1] + t12 * Vinv_ij[1][2] + t24 * (t21 * t23 * t6 - t19 * (-t1 * Vinv_ij[2][0] + t3 * Vinv_ij[0][0])) + t31 * (t15 * t23 * t6 - t19 * (-t1 * Vinv_ij[2][2] + t3 * Vinv_ij[0][2])) + t32 * (t23 * t29 * t6 - t19 * (-t1 * Vinv_ij[2][1] + t3 * Vinv_ij[0][1])); t6 = (t16 * t1 * t26 + t14 * t2 * t13) * t20; t1 = t10 * Vinv_ij[2][0] + t11 * Vinv_ij[2][1] + t12 * Vinv_ij[2][2] + t24 * (-t21 * t23 * t6 + t19 * (-t1 * Vinv_ij[1][0] + t2 * Vinv_ij[0][0])) + t31 * (-t15 * t23 * t6 + t19 * (-t1 * Vinv_ij[1][2] + t2 * Vinv_ij[0][2])) + t32 * (-t23 * t29 * t6 + t19 * (-t1 * Vinv_ij[1][1] + t2 * Vinv_ij[0][1])); t2 = 0.2e1; gradE[0] = -t2 * (-t24 * (t23 * t22 * t21 + t19 * (t25 * Vinv_ij[1][0] - t27 * Vinv_ij[2][0])) + t33 * Vinv_ij[0][0] + t30 * Vinv_ij[0][1] + t17 * Vinv_ij[0][2] - t32 * (t23 * t22 * t29 + t19 * (t25 * Vinv_ij[1][1] - t27 * Vinv_ij[2][1])) - t31 * (t23 * t22 * t15 + t19 * (t25 * Vinv_ij[1][2] - t27 * Vinv_ij[2][2]))); gradE[1] = -t2 * t35; gradE[2] = -t2 * t34; gradE[3] = t2 * t36; gradE[4] = t2 * t9; gradE[5] = t2 * t4; gradE[6] = t2 * t5; gradE[7] = t2 * t3; gradE[8] = t2 * t1;

Hessian

 (1.5.1)

## How do I differentiate this in Maple?...

Dear Experts,

Please how do I carry out the differentiation of

`y[1](t)*y[2](t)*(y[1](t)+y[2](t))^3`

with respect to y[1] using maple? I know how to use maple if the derivative is with respect to t.
Thank you in anticipation

## tridiagonal linear system ...

Dear all

I would like to solve a linear system A X=b whee A is a matrix n times n

If A is a tri-diagonal matrix, how can we write simple code to make A upper-triangular and then we solve the system using backward substitution

many thanks

## A strange bug, perhaps in limit....

Here is a strange one...

1> /Library/Frameworks/Maple.framework/Versions/2019/bin/maple ; exit;
|\^/|     Maple 2019 (APPLE UNIVERSAL OSX)
._|\|   |/|_. Copyright (c) Maplesoft, a division of Waterloo Maple Inc. 2019
<____ ____>  Waterloo Maple Inc.
|       Type ? for help.
> version():
User Interface: 1435526
Kernel: 1435526
Library: 1435526
> I0:=(x - 11)^(n)*x/(x^(n + 1));
n
(x - 11)  x
I0 := -----------
(n + 1)
x

> I1:=(x - 11)^(n)/(x^(n));
n
(x - 11)
I1 := ---------
n
x

> is(I1=I0);
memory used=2.5MB, alloc=40.3MB, time=0.14
true

> Limit(I0,x=infinity)=limit(I0,x=infinity) assuming n::posint;
n
(x - 11)  x
lim       ----------- = infinity
x -> infinity    (n + 1)
x

> Limit(I1,x=infinity)=limit(I1,x=infinity) assuming n::posint;
n
(x - 11)
lim       --------- = 1
x -> infinity      n
x

This was in Maple 2019.2 ... but I had Maple 18 (from 2014) running here, and it does the same thing.

How strange is this: replace 11 by 10 (or less) and the error goes away.

## Is there a tetrahedron or not...

Recently found out about Steiner ellipsoids. This is an ellipsoid inscribed in a tetrahedron, and an ellipsoid described near a tetrahedron. One ellipsoid touches the faces of the tetrahedron in centroids, the other ellipsoid touches the planes in vertices of the tetrahedron, and these planes are parallel to the faces.
steiner_in_ellipsoid.mw
steiner_out_ellipsoid.mw

There is a desire to find out if 4 vertices determine the tetrahedron or not. And it seems Maple answer this question:

```restart: with(geom3d):
point(A, 0, 0, 0), point(B, 1, 0, 0), point(C, 0, 0, 1), point(F, 0, 1, 0):
gtetrahedron(T1, [A, B, C, F]):
i := nops(op(0, detail(T1)));
if i = 1 then print("Ok gtetrahedron") else print("No gtetrahedron") end if:
```

I want to stop further execution of the program if the tetrahedron is not determine, for example, when point
B = [0,0,0], but I don’t know how to do it.