Maple Questions and Posts

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y''(x)+2(y'(x))^2+8y(x)=0   

y(0)=0 , y'(0)=1

Hello there, 

Is there any chance to ask if there is a way to simplify the numeric outcome from an operation?

Here is what I've been trying:

restart;

with(LinearAlgebra):

interface(imaginaryunit=j):

Amat := Matrix(2, 2, [[-0.1428571428*K__D, -0.1081971238], [376.9911185, 0]]);

Matrix(2, 2, {(1, 1) = -.1428571428*`#msub(mi("K"),mi("D",fontstyle = "normal"))`, (1, 2) = -.1081971238, (2, 1) = 376.9911185, (2, 2) = 0})

(1)

Eigenvalues(Amat);

Vector(2, {(1) = -0.7142857140e-1*`#msub(mi("K"),mi("D",fontstyle = "normal"))`+0.2000000000e-9*sqrt(0.1275510203e18*`#msub(mi("K"),mi("D",fontstyle = "normal"))`^2-0.1019733868e22), (2) = -0.7142857140e-1*`#msub(mi("K"),mi("D",fontstyle = "normal"))`-0.2000000000e-9*sqrt(0.1275510203e18*`#msub(mi("K"),mi("D",fontstyle = "normal"))`^2-0.1019733868e22)})

(2)

Desired := sqrt((2.000000000*10^(-10))^2 * (1.275510203*10^17*K__D^2 - 1.019733868*10^21));

(0.5102040812e-2*K__D^2-40.78935472)^(1/2)

(3)

 


I tried to simplify the Eigen values, to make them in the formality of the 'Desired' numerical expression, but no success yet. 

Thank you, 

Download Q20230110_m1.mw

Consider this matrix

a b c

b c a

c a b

I would like to reference the entries with letters, not numbers.  The b,c entry would be a, for instance.  Any way to do this?

Hello,

  2022 was a wonderful year of progress in using Maple/MapleSim for almost everything my mathematical world.     

I just wanted to wish all the Maplesoft user community a very productive and Happy New Year for 2023.   I look forward to continue to find great nuggets of capability and insider techniques for using Maple in my endeavors.

Kindest Regards to ALL.
Happy New Year - 2023.
Bill

Hello,

    I am manually re-creating the TS diagram for phase plot of fluid=air for use in a report as a pretty plot.   The TemperatureEntropyChart function is colored in grayscale.  I really need to change to colorized for additional data being added.

   The code to generate the various isobars color gradient is shadebetween two curves.   

    Using the code method to plot leaves white gaps in the discontinutiy of the plot curves returned from the Property function at the liquid and vapor lines.   I have manually connected the horizontal "under the dome" in a matrix of X,Y for each of two isobar curves.

   However, the shadebetween doesn't seem to like the two X,Y matrices for the curves as inputs to shadebetween.

    So,...   Q:   1.)  Can the color be changed using the TempertureEntropyChart function,..or
                      2.)  Can matrices of unequal X,Y values (scatterplot type data sets) be used for the curves in shadebetween command?  The help infers the Y (v, of (u,v))  values need to match.

Thanks,
Bill

Ref:    worksheet contained at:  https://www.mapleprimes.com/maplesoftblog/203462-Computing-With-Thermophysical-Data

Give a Data for regression in excel sheet with many independent variables as much as 50 and one dependent variable. where first row is dependent variable say

Is their anyway in maplesoft to split into Train and test set 

Then it choose only best set of independent variables to model the dependent variable Y Linear regression

Is their any Toolbox or anyway we can do it

Can anyone help to write a code for this in Maple

Kind help.

Please help with a sample example program Kind help

restart

with(DEtools); with(LinearAlgebra)

diff(u(x, t), t) = [Matrix([[0, (1/2)*mu*k^2], [2*A^2-(1/2)*mu*k^2, 0]])]*u(x, t)

diff(u(x, t), t) = [Matrix(%id = 36893489823894642308)]*u(x, t)

(1)

"where u(x,t)=[u1 u2]^(T) is a vector. The solution of differential equation (1) is u=v*exp(w*t)."

where*w^2 = -(1/4)*mu^2*k^4+mu*k^2*A^2

"How can we solve differntial equation*(1) on Maple"?""

NULL

Download dsol.mw

Hello guys
Could someone help me create a simple palette to contain, for example, three functions that I use constantly?

           conve1(a), conve2(a) and conve3(a).

I tried through the help documentation, but I couldn't.

Sincerely,
Oliveira

hello. i write a for loop and i want to maple give me the answer like the below pic
thanks in advance

for oo to 2 do
    M[oo] := EI*(4*theta(oo) + 2*theta(oo + 1))/L;
end do;

Hello,

I use Maple 2022 on a MacBook Pro. In most of the plots I create I use symbol=solidcircle and symbolsize=12.

Is there a way to make those (and perhaps oher) settings user default so I don't need them in every plot command?

Thanks.

Jose


This post is inspired by a serie of questions from @JAMET.
I wondered if it was possible to prove plane geometry theorems with the geometry package.

Here is an illustration for the Poncelet's theorem for the triangle (French designation), see for instance
https://en.wikipedia.org/wiki/Poncelet%27s_closure_theorem

Are any of you interested in challenging the geometry package to proof other plane geometry theorems?
 

restart:


Poncelet's theorem for the triangle

Let ABC a triangle, c its incircle (center omega, radius r) and C its circumcircle (center Omega, radius R).
Let D the distance between omega and Omega.

then R^2 - D^2 - 2*r*R = 0


Proof

Without loss of generality one sets :

    x(A) = y(A) = 0
   and  y(B) = 0

ABC is a non degerated triangle provided x(B) <> 0 and y(C) <> 0
 

with(geometry):

kernelopts(version);

`Maple 2020.2, X86 64 WINDOWS, Nov 11 2020, Build ID 1502365`

(1)

assume(x__B <> 0):
assume(y__C <> 0):

point(A, 0, 0);
point(B, x__B, 0);
point(C, x__C, y__C);

A

 

B

 

C

(2)

triangle(T, [A, B, C])

T

(3)

bisector(bA, A, T);
bisector(bB, B, T);

eA := isolate(Equation(bA, [x, y]), y):
eB := isolate(Equation(bB, [x, y]), y):

xc := solve(rhs(eA)=rhs(eB), x):
yc := eval(rhs(eA), x=xc):

point(omega, xc, yc):
r := distance(omega, line(lAB, [A, B]))

bA

 

bB

 

(abs(x__B)^2)^(1/2)*abs(x__B*y__C/((x__B^2-2*x__B*x__C+x__C^2+y__C^2)^(1/2)+(x__C^2+y__C^2)^(1/2)+(x__B^2)^(1/2)))/(x__B^2)^(1/2)

(4)

circumcircle(C, T, 'centername' = Omega);
R := radius(C);

C

 

((1/4)*x__B^2+(1/4)*(-x__B*(x__C^2+y__C^2)+x__C*x__B^2)^2/(x__B^2*y__C^2))^(1/2)

(5)

Oo := distance(Omega, omega)

(((1/2)*x__B-(x__B*(x__C^2+y__C^2)^(1/2)+x__C*(x__B^2)^(1/2))/((x__B^2-2*x__B*x__C+x__C^2+y__C^2)^(1/2)+(x__C^2+y__C^2)^(1/2)+(x__B^2)^(1/2)))^2+(-(1/2)*(-x__B*(x__C^2+y__C^2)+x__C*x__B^2)/(x__B*y__C)-y__C*(x__B^2)^(1/2)/((x__B^2-2*x__B*x__C+x__C^2+y__C^2)^(1/2)+(x__C^2+y__C^2)^(1/2)+(x__B^2)^(1/2)))^2)^(1/2)

(6)

S := simplify(R^2 - Oo^2 - 2*r*R)  assuming x__B::real, x__C::real, y__C::real

((x__B^2*(-abs(y__C)*signum(y__C)+y__C)*(x__C^2+y__C^2)^(1/2)+x__C^2*(y__C*abs(x__B)-signum(y__C)*abs(x__B*y__C)))*(x__B^2-2*x__B*x__C+x__C^2+y__C^2)^(1/2)+(-signum(y__C)*(x__C-x__B)^2*abs(x__B*y__C)+(abs(x__B)^2+x__C*(x__C-2*x__B))*abs(x__B)*y__C)*(x__C^2+y__C^2)^(1/2))/(y__C*((x__B^2-2*x__B*x__C+x__C^2+y__C^2)^(1/2)+(x__C^2+y__C^2)^(1/2)+abs(x__B))^2)

(7)

simplify(S) assuming x__B > 0, y__C > 0;
simplify(S) assuming x__B > 0, y__C < 0;
simplify(S) assuming x__B < 0, y__C > 0;
simplify(S) assuming x__B < 0, y__C < 0;

0

 

0

 

0

 

0

(8)

 

 

Download PoTh_proof.mw


Improvements of the geometry package                                                                                           

It already appears that (some) assumptions are not (always) correctly taken into account. This is a weak point which requires, as in the attached mw, to use an indirect approache to construct the incircle.

As a matter of fact, the procedure incircle, whose first lines are

showstat(incircle)

geometry:-incircle := proc(inci, T)
local cname, d, A, B, l1, l2, dis, x, y, tmp, msg;
   1   if nargs < 2 or 3 < nargs then
   2     error "wrong number of arguments"
       end if;
   3   if geometry:-form(T) <> ('triangle2d') then
   4     error "wrong type of arguments"
       end if;
   5   if nargs = 3 and op(1,args[3]) = ('centername') and type(op(2,args[3]),'name') then
   6     cname := op(2,args[3])
       else
   7     cname := cat('center_',inci)
       end if;
   8   if geometry:-method(T) = (':-points') then
   9     d := geometry:-DefinedAs(T);
  10     A := op(1,d);
  11     B := op(2,d);
  12     msg := sprintf("find the bisector of %a at vertex %a",T,A);
  13     userinfo(2,geometry,msg);
  14     geometry:-bisector('l1',A,T);
  15     msg := sprintf("find the bisector of %a at vertex %a",T,B);
  16     userinfo(2,geometry,msg);
  17     geometry:-bisector('l2',B,T);
  18     msg := sprintf("find the intersection of the two bisectors");
  19     userinfo(2,geometry,msg);
  20     geometry:-intersection(cname,l1,l2);

requires that the two bissectors are not parallel(call to geometry:-intersection).

Since the non-parallelism of bisectors is trivial for all non-degenerate triangles, why doesn't incircle inherit this property rather than not being able to decide if the bisectors are parallel or not?)

Here is a detail of what happens and the endless loop in which incircle seems to be caught

kernelopts(version);
                  Maple 2015.2, APPLE UNIVERSAL OSX, Dec 20 2015, Build ID 1097895

AreParallel(bA, bB, 'condition'):
        AreParallel: hint: cannot determine if -y__C*(x__B^2)^(1/2)*(x__C*(x__B^2)^(1/2)-x__B*(x__B^2)^(1/2)-x__B*((x__B-x__C)^2+y__C^2)^(1/2))+y__C*(x__B^2)^(1/2)*(x__B*(x__C^2+y__C^2)^(1/2)+x__C*(x__B^2)^(1/2)) is zero

assume(lhs(condition) <> 0);
AreParallel(bA, bB);
                             false
intersection(J, bA, bB);
                               J


infolevel[geometry] := 4:
incircle(inc, T);
incircle: find the bisector of T at vertex A
incircle: find the bisector of T at vertex B
incircle: find the intersection of the two bisectors
intersection: find the intersection between two lines l1 and l2
intersection: one point of intersection
incircle: find the radius of the incircle
line: define the line from two points
circle: define the circle from its center and radius
circle: hint: abs(x__B^2*y__C/(csgn(x__B)*x__B+(x__B^2-2*x__B*x__C+x__C^2+y__C^2)^(1/2)+(x__C^2+y__C^2)^(1/2)))/(x__B^2)^(1/2) > 0
Error, (in geometry:-circle) not enough information: the radius might not be positive
assume(abs(x__B^2*y__C/(csgn(x__B)*x__B+(x__B^2-2*x__B*x__C+x__C^2+y__C^2)^(1/2)+(x__C^2+y__C^2)^(1/2)))/(x__B^2)^(1/2) > 0):

assume(abs(x__B^2*y__C/(csgn(x__B)*x__B+(x__B^2-2*x__B*x__C+x__C^2+y__C^2)^(1/2)+(x__C^2+y__C^2)^(1/2)))/(x__B^2)^(1/2) > 0): 
incircle(inc, T);
incircle: find the bisector of T at vertex A
incircle: find the bisector of T at vertex B
incircle: find the intersection of the two bisectors
intersection: find the intersection between two lines l1 and l2
AreParallel: hint: cannot determine if -y__C*(x__B^2)^(1/2)*(x__C*(x__B^2)^(1/2)-x__B*(x__B^2)^(1/2)-x__B*((x__B-x__C)^2+y__C^2)^(1/2))+y__C*(x__B^2)^(1/2)*(x__B*(x__C^2+y__C^2)^(1/2)+x__C*(x__B^2)^(1/2)) is zero
intersection: two given lines intersect each other if -y__C*(x__B^2)^(1/2)*(x__C*(x__B^2)^(1/2)-x__B*(x__B^2)^(1/2)-x__B*((x__B-x__C)^2+y__C^2)^(1/2))+y__C*(x__B^2)^(1/2)*(x__B*(x__C^2+y__C^2)^(1/2)+x__C*(x__B^2)^(1/2)) <> 0
Error, (in geometry:-intersection) not enough information

assume(-y__C*(x__B^2)^(1/2)*(x__C*(x__B^2)^(1/2)-x__B*(x__B^2)^(1/2)-x__B*((x__B-x__C)^2+y__C^2)^(1/2))+y__C*(x__B^2)^(1/2)*(x__B*(x__C^2+y__C^2)^(1/2)+x__C*(x__B^2)^(1/2)) <> 0):
incircle(inc, T);
incircle: find the bisector of T at vertex A
incircle: find the bisector of T at vertex B
incircle: find the intersection of the two bisectors
intersection: find the intersection between two lines l1 and l2
intersection: one point of intersection
incircle: find the radius of the incircle
line: define the line from two points
circle: define the circle from its center and radius
circle: hint: abs(x__B^2*y__C/(csgn(x__B)*x__B+(x__C^2+y__C^2)^(1/2)+(x__B^2-2*x__B*x__C+x__C^2+y__C^2)^(1/2)))/(x__B^2)^(1/2) > 0
Error, (in geometry:-circle) not enough information: the radius might not be positive


 

 

After studying the plottools:-transform command, I intend to visualize the following regions with constrained parameters in 
 

(plottools[transform](proc (u, v) options operator, arrow; [u^3-v^2, u^2-v^3] end proc))(plots[inequal](`or`(u^2+4*v^2 <= 4, `and`(u^2+v^2 < 4, 4*v >= (u+2)^2+2*v^2)), nolines))

 

(plottools[transform](proc (s, t) options operator, arrow; [s^2*sqrt(t)*cos(t), s^2*sin(t)] end proc))(plots[inequal](`and`(`and`(s >= 1, 5*s <= 5+t), t < 5), s = 1 .. 2, t = 0 .. 5))

 

 

But Mma gives 

The first instance (with default settings) is the same, but as for the second instance, which graph is correct? 

restart;
with(plottools):
with(plots):
transform((u, v) -> [u^3 - v^2, u^2 - v^3])(inequal(Or(u^2 + 4*v^2 <= 4, And(u^2 + v^2 < 4, (u + 2)^2 + 2*(v - 1)^2 <= 2)), nolines));
transform((s, t) -> [s^2*sqrt(t)*cos(t), s^2*sin(t)])(inequal(`and`(1 <= s, 5*s <= 5 + t, t < 5), s = 1 .. 2, t = 0 .. 5));


Download TransformedRegion.mws

I take the liberty to rephrase my previous question as I believe the title was not very clear and so maybe some power users did not look at it. I am making the transition from Mathcad towards Maple and get stuck solving the equation in the attached worksheet. In mathcad I would solve it like this:

How can I achieve results in Maple? I know it is a very powerful program but for me the learning curve is at this moment quite steep. Any help would be very much appreciated.

Multiple_input.mw

plot-problem.mw

I have done something but what?

I want to use maple notation for input and  output.

I have done something to mess this up.

How do I get rid of the typesetting messages?

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