Maple Questions and Posts

These are Posts and Questions associated with the product, Maple

Hello!
Used PolyhedralSets for plotting.
At the moment there are a number of questions in the construction of graphs:
Нов to make, what color of a figure received in a cut would be much darker or Darker color?

with(PolyhedralSets);
P1 := PolyhedralSet({-x-20 <= 0, -x-20 <= 20-y, -x-20 <= -(1/2)*y, -x-20 <= -z, -x-20 <= -(x+y)*(1/2), -x-20 <= -(y+z)*(1/2)});
Plot(P1, axes = normal, view = [-40 .. 40, -40 .. 40, -40 .. 40], orientation = [30, -30, -60], color = blue, thickness = 2);
Plot(P1, axes = normal, view = [-40 .. 40, -40 .. 40, -40 .. -40], orientation = [0, 0, 0], color = blue, thickness = 2)


Hello!
Used PolyhedralSets for plotting.
At the moment there are a number of questions in the construction of graphs:
How to adjust the rotation of this figure around the z axis?
How to make, what color of a figure received in a cut would be much darker or Darker color?

with(PolyhedralSets);
P1 := PolyhedralSet({-x-20 <= 0, -x-20 <= 20-y, -x-20 <= -(1/2)*y, -x-20 <= -z, -x-20 <= -(x+y)*(1/2), -x-20 <= -(y+z)*(1/2)});
Plot(P1, axe
s = normal, view = [-40 .. 40, -40 .. 40, -40 .. 40], orientation = [30, -30, -60], color = blue, thickness = 2);
Plot(P1, axes = normal, view = [-40 .. 40, -40 .. 40, -40 .. -40], orientation = [0, 0, 0], color = blue, thickness = 2)





I'm trying to obtain integral of Planck radiation law in Maple:

with this command:

f := (2*h*(c)^(2))/((x)^(5))*(1)/(exp((h*c)/(x*k*T))-1);
int(f,x=0..infinity);

but I get some terrible limit that cannot be solved instead of the correct result:

How to obtain correct integral?

planck.mw

 

the program shows that the error please verify it sirprogram11.mw

what's the problem with PDE below? tnx for help


 

restart:

PDE:=diff(u(x,t),t)=k*diff(u(x,t),x$2)-h*u(x,t);

diff(u(x, t), t) = k*(diff(diff(u(x, t), x), x))-h*u(x, t)

(1)

IBC := {u(-Pi,t)=u(Pi,t), (D[1](u))(-Pi, t) = (D[1](u))(Pi, t),u(x,0)=sin(x)};

{u(x, 0) = sin(x), u(-Pi, t) = u(Pi, t), (D[1](u))(-Pi, t) = (D[1](u))(Pi, t)}

(2)

pdsolve(PDE,IBC);

Error, (in pdsolve/sys) too many arguments; some or all of the following are wrong: [{u(x, t)}, {u(x, 0) = sin(x), u(-Pi, t) = u(Pi, t), (D[1](u))(-Pi, t) = (D[1](u))(Pi, t)}]

 

 


 

Download PDE_problem.mw

Hi

I have two equations as follows:

The goal is finding the parameter 'phi'. This parameter is a positive real numeric constant.

I uploaded two files that they are included two methods to solve the problem.

1.mw

2.mw

Is method in the first file mathematically logical? If it is a correct method, why the command fsolve dosent work?

In file 2, we have 2 equations with further indeterminantes. The constant 'phi' must be minimum possible amount. How we can use the commands like the Minimize in Optimization? Please hint me.

Moreover, if there is a method to solve this problem please help me to know.

Thank you very much 

 

 

I want to set the position of the legend inside the figure window for example say top right in the figure window. Maple chose the legend to be at right, left, top, bottom outside the figure window. How can I place the legend of my own wish?

thanks,

I am coding a big module to solving my project : analyze function in math, but when I compile my module maple return "Error," but it doesn't tell me what error happened.

I check the maple help and it said:" If no msgString is given, error raises the most recently occurring exception" but I have no exception before. 

This is the pic of that error.

Thank for your help.

I would like to look at a 3d plot including an condition about the tree variables of the plot

For this simple case, I only want to see the plot with the condition that 
{40 < y, x < y-40, z < y-40} or {x = 0, y = 40, z <= 0}, {y = x+40, 0 < x, z < x}, {y = x+40, z = x, 0 < x}

. Is that possible? 

In 2d there is no problem. And in 3d I do not know how.

restart; with(plots, implicitplot);
print(`output redirected...`); # input placeholder
                         [implicitplot]
p; .2; omega[0] := 1; epsilon[1] := 1.04493; epsilon[2] := .93259; delta := 0.2e-1;
eq := [[omega[0]*a-a*Omega^2+(3/4)*epsilon[2]*a^3]^2+(delta*Omega*a)^2 = p^2];
print(`output redirected...`); # input placeholder
implicitplot(eq, omega = .5 .. 2, a = 0 .. 5, p = 0 .. 1, color = blue, thickness = 2, gridrefin = 6);
%;
Error, (in plots/implicitplot) invalid input: the following extra unknowns were found in the input expression: {Omega, p}

Hello

I am exploring the Statistics package to see how Maple implements the transformation of random variables.  Unfortunately, I got stuck when trying the following example.

W->X+Y and then X-> W/2

For the first part, I did

w:=RandomVariable(BetaDistribution(1,m-1))+RandomVariable(BetaDistribution(1,m-1))

but for the second part I could not figure out what to do.

Any suggestions?

Many thanks

Ed

 

 

Hi everybody,

 

I'm working under Windows 7 

 

My need :
A MAPLE code has to be run from an ECLIPSE session (through a cmaple MyCode).
In this ECLIPSE session the user chooses a data file among many, and ECLIPSE then has to tell MyCode what file it has to read.


The solution I figured out :
Step 1 : ECLIPSE  set an environment variable "DataFile" which contains the user's choice, for instance set MyData=NameOfTheFile
Step 2 : Within MyCode I get the value of MyData from these two commands

MyFile := getenv(DataFile):

readdata(MyFile, …)

 

This doesn't work ( getenv(DataFile) returns [1," "] instead of the desired file name).
In fact it seems that getenv enables access to the “native” environment variables of Windows only (for instance HOMEDIR), not to the user defined environment variables (?)


Is  it possible to fix this and how ?

PS  : I face the same difficulties if I type set MyData=NameOfTheFile directly from a cmd command and try to access the value of MyData from a Maple session


Thanks for your help

 

 

solve(diff(-1/x,x) = (-1/x)^(b), b);

originally is 2, but it use ln(....) to express
 
if start from substitute, it seems need to replace manually.

solve(subs(a(x)=-1/x,diff(a(x),x) = (a(x))^(b)), b);

 
goal is to find b in equation below
solve(diff((x^2+x+1)/(-1+x)^2,x) = ((x^2+x+1)/(-1+x)^2)^(b), b);
(2*x+1)/(-1+x)^2-(2*(x^2+x+1))/(-1+x)^3 = ((x^2+x+1)/(-1+x)^2)^(b)
 
solve(diff((x^2+x+1)/(-1+x)^2,x) = ((x^2+x+1)/(-1+x)^2)*(b), b);

Hi, my dear friend,

i am solving 9 ODE with boundary conditionsNigam.mw

Eq1 := 2.*F1(eta)+diff(H1(eta), eta) = 0

2.*F1(eta)+diff(H1(eta), eta) = 0

(1)

Eq2 := F1(eta)^2-G1(eta)^2+(diff(F1(eta), eta))*H1(eta)-(diff(F1(eta), eta, eta)) = 0

F1(eta)^2-G1(eta)^2+(diff(F1(eta), eta))*H1(eta)-(diff(diff(F1(eta), eta), eta)) = 0

(2)

Eq3 := 2*F1(eta)*G1(eta)+H1(eta)*(diff(G1(eta), eta))-(diff(G1(eta), eta, eta)) = 0

2*F1(eta)*G1(eta)+H1(eta)*(diff(G1(eta), eta))-(diff(diff(G1(eta), eta), eta)) = 0

(3)

Eq4 := 4*F1(eta)*F3(eta)+H3(eta)*(diff(F1(eta), eta))+H1(eta)*(diff(F3(eta), eta))-2*G1(eta)*G3(eta)-2.*F1(eta)^2-1.5*H1(eta)-(diff(F3(eta), eta, eta)) = 0

4*F1(eta)*F3(eta)+H3(eta)*(diff(F1(eta), eta))+H1(eta)*(diff(F3(eta), eta))-2*G1(eta)*G3(eta)-2.*F1(eta)^2-1.5*H1(eta)-(diff(diff(F3(eta), eta), eta)) = 0

(4)

Eq5 := 2*F3(eta)*G1(eta)+4*F1(eta)*G3(eta)+H3(eta)*(diff(G1(eta), eta))-H1(eta)*(diff(G3(eta), eta))-2*F1(eta)*G1(eta)-1.5*H1(eta)*(diff(G1(eta), eta))-(diff(G3(eta), eta, eta)) = 0

2*F3(eta)*G1(eta)+4*F1(eta)*G3(eta)+H3(eta)*(diff(G1(eta), eta))-H1(eta)*(diff(G3(eta), eta))-2*F1(eta)*G1(eta)-1.5*H1(eta)*(diff(G1(eta), eta))-(diff(diff(G3(eta), eta), eta)) = 0

(5)

Eq6 := 4.*F3(eta)+diff(H3(eta), eta) = 0

4.*F3(eta)+diff(H3(eta), eta) = 0

(6)

Eq7 := 6*F1(eta)*F5(eta)-6*F1(eta)*F3(eta)+3.*F3(eta)^2+H1(eta)*(diff(F5(eta), eta))+H3(eta)*(diff(F3(eta), eta))+H5(eta)*(diff(F1(eta), eta))-1.5*(H1(eta)*(diff(F3(eta), eta))+H3(eta)*(diff(F1(eta), eta)))-G3(eta)^2-2*G1(eta)*G5(eta)-(diff(F5(eta), eta, eta)) = 0

6*F1(eta)*F5(eta)-6*F1(eta)*F3(eta)+3.*F3(eta)^2+H1(eta)*(diff(F5(eta), eta))+H3(eta)*(diff(F3(eta), eta))+H5(eta)*(diff(F1(eta), eta))-1.5*H1(eta)*(diff(F3(eta), eta))-1.5*H3(eta)*(diff(F1(eta), eta))-G3(eta)^2-2*G1(eta)*G5(eta)-(diff(diff(F5(eta), eta), eta)) = 0

(7)

Eq8 := 6*G5(eta)*F1(eta)+2*G1(eta)*F5(eta)+4*G3(eta)*F3(eta)-4*F1(eta)*G3(eta)-2*F3(eta)*G1(eta)+H1(eta)*(diff(G5(eta), eta))-1.5*(H1(eta)*(diff(G3(eta), eta))+H3(eta)*(diff(G1(eta), eta)))+H3(eta)*(diff(G3(eta), eta))+H5(eta)*(diff(G1(eta), eta))-(diff(G5(eta), eta, eta)) = 0

6*G5(eta)*F1(eta)+2*G1(eta)*F5(eta)+4*G3(eta)*F3(eta)-4*F1(eta)*G3(eta)-2*F3(eta)*G1(eta)+H1(eta)*(diff(G5(eta), eta))-1.5*H1(eta)*(diff(G3(eta), eta))-1.5*H3(eta)*(diff(G1(eta), eta))+H3(eta)*(diff(G3(eta), eta))+H5(eta)*(diff(G1(eta), eta))-(diff(diff(G5(eta), eta), eta)) = 0

(8)

Eq9 := 6.*F5(eta)+F3(eta)+diff(H5(eta), eta) = 0

6.*F5(eta)+F3(eta)+diff(H5(eta), eta) = 0

(9)

bcs1 := F1(0) = 0, F3(0) = 0, F5(0) = 0

F1(0) = 0, F3(0) = 0, F5(0) = 0

(10)

bcs2 := G1(0) = 1, G3(0) = 0, G5(0) = 0

G1(0) = 1, G3(0) = 0, G5(0) = 0

(11)

bcs3 := H1(0) = 0, H3(0) = 0, H5(0) = 0

H1(0) = 0, H3(0) = 0, H5(0) = 0

(12)

bcs4 := F1(10) = 0, F3(10) = 0, F5(10) = 0

F1(10) = 0, F3(10) = 0, F5(10) = 0

(13)

bcs5 := G1(10) = 0, G3(10) = 0, G5(10) = 0

G1(10) = 0, G3(10) = 0, G5(10) = 0

(14)

R := dsolve(eval({Eq1, Eq2, Eq3, Eq4, Eq5, Eq6, Eq7, Eq8, Eq9, bcs1, bcs2, bcs3, bcs4, bcs5}), [F1(eta), F3(eta), F5(eta), G1(eta), G3(eta), G5(eta), H1(eta), H3(eta), H5(eta)], numeric, output = listprocedure)

Error, (in dsolve/numeric/bvp) initial Newton iteration is not converging

 

``


Maple Worksheet - Error

Failed to load the worksheet 

Download Nigam.mwNigam.mw

then i got this error

Error, (in dsolve/numeric/bvp) initial Newton iteration is not converging

i dont know where i need to change.. could you help me..

hi:

i'm using expand cmd, but surprisingly, not only execute the expand but execute simplify cmd. Is there any cmd only execute expand withoud simplify?

Best wishes,

from China

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