how i can save results on text file from pdsolve?

thanks

maple11.mw
 

Download maple11.mw

Hello everyone, I use physics package and I input:

with(Physics)

Setup(mathematicalnotation = true)

Coordinates(X)

Setup(tensors = A[mu](X))

PDEtools:-declare(A(X))

PDEtools:-declare(p0(X), pm(X), pp(X), pt(X), Un(X), Ucn(X))

pt := proc (X) options operator, arrow; Matrix(2, 2, [[p0(X), sqrt(2)*pp(X)], [sqrt(2)*pm(X), -p0(X)]]) end proc

U := proc (X) options operator, arrow; Matrix(2, 2, [[1, 0], [0, 1]])+I*pt(X)*(1/f)-pt(X)*pt(X)*((1/2)/f^2) end proc

Ucn := proc (X) options operator, arrow; Matrix(2, 2, [[1, 0], [0, 1]])-I*pt(X)*(1/f)-pt(X) . pt(X)*((1/2)/f^2) end proc

And after that I write:

Trace(-LeviCivita[mu, nu, rho, sigma] . Ucn(X) . ((1/6)*e*A[nu](X)+M5*KroneckerDelta[nu, 0]) . Matrix(2, 2, [[1, 0], [0, 1]]) . Uсn(X) . d_[rho](Un(X)) . Uсn(X) . d_[sigma](Un(X)))

But I get an error:

Error, (in unknown) invalid subscript selector

Thanks for the help.

Dear all ;

I have a Partial differential equation

restart; with(PDEtools);

pde[2] := (diff(u(x, y), x))*(diff(u(x, y), x, x))+diff(u(x, y), y, y);
    where x and y in the square [0,1]

with boundary condition 

bc[2] := u(0, y) = 0, u(1, y) = 0, u(x, 0) = 0, u(x, 1) = 0;

Is there a simple code to compute the solution

Many thanks for any help

I am looking for persons with experience in setting up maple for the blind. The setting is a 21-year old blind
 student who wants to do math. He uses Mac OS/X and the built-in VoiceOver screen reader, plus refreshable Braille display (one-line), a Braille printer, and Nemeth, the Braille extension for math symbols.

Initially, we are working from no experience whatsoever, trying ideas, mostly failure. Getting some advice from persons who are blind and using maple would be wonderful. If anyone knows of an instance, a person who is blind and regularly uses maple, then we would both would be delighted to receive advice on what to install, how to set it up, and how to use maple on a daily basis.

One trouble for the VoiceOver screen reader is verbosity of maple output. Any methods to reduce the amount of output would be welcome. To uderstand the issue, look at the output of these two commands when interface(prettyprint=0) has been set to help out the VoiceOver screen reader:

matrix([[1,2],6,7]]); Matrix([[1,2],[6,7]]);

The first outputs the same text, which VoiceOver will read accurately. The second dumps out two lines of extraneous and confusing information, only 20% of which is useful. The verbosity is not restricted to matrix packages linalg or LinearAlgebra. It is a problem wtih nearly all packages.

-Grant Gustafson, Salt Lake City, Univ of Utah Math Dept

Hi,

I have a Maple code which produces an output plot for a first order differential equation,

nde := evalf(subs(npar, de));
nds := dsolve({nde, sigma(0) = -1e-8}, sigma(t), type = numeric);
acc_nds := (sig0, ae, re) -> dsolve({nde, sigma(0) = sig0}, sigma(t), type = numeric,
method = lsode[backfull], abserr = ae, relerr = re, maxfun = 0, ctrl=Ctrl);

odeplot(acc_nds(-0e-7, 1e-13, 1e-13), [t, sigma(t)], t = 0..2);

This produces the outputplot that I need for sigma(t). I need to produce a outut for d(sigmat)/dt, and how can this be done? what is the command I should use?

Additionally, how can i get the data set out of the polt in to a excel file or a text file?

I am quite new to maple, so i expect your kind support

Thanks

I'm doing this interactive component and for coordinates of points I use one TextArea for each coordinate.

a:= Do(%CB);

x1:=Do (%x1);
y1:=Do (%y1);
x2:=Do (%x2);
y2:=Do (%y2);
x3:=Do (%x3);
y3:=Do (%y3);
x4:=Do (%x4);
y4:=Do (%y4);
x5:=Do (%x5);
y5:=Do (%y5);

#x6:=Do (%x6);
#y6:=Do (%y6);
#x7:=Do (%x7);
#y7:=Do (%y7);
#x8:=Do (%x8);
#y8:=Do (%y8);
#x9:=Do (%x9);
#y9:=Do (%y9);
#x10:=Do (%x10);
#y10:=Do (%y10);




vx2:=[x1,x2];
vy2:=[y1,y2];

vx3:=[x1,x2,x3];
vy3:=[y1,y2,y3];

vx4:=[x1,x2,x3,x4];
vy4:=[y1,y2,y3,y4];

vx5:=[x1,x2,x3,x4,x5];
vy5:=[y1,y2,y3,y4,y5];



if a=2 then F2:=y=LinearFit([1, x], vx2, vy2, x);
end if:

if a=3 then F3:=evalf[2](LinearFit([1, x], vx3, vy3, x));
end if:


if a=4 then F4:=LinearFit([1, x], vx4, vy4, x);
end if:


if a=5 then F5:=LinearFit([1, x], vx5, vy5, x);
end if:

I was browsing on maple and i sow this:

I would use a table to insert coordinates of point like this image, but i don't know how can I do.

Can you help me plese?

Thanks in advance
Enrico

Dear friends:

I am facing two problems

1. one is to get solution of the below system of ODE for L=100 (highlited as red) and

2. the other is I want the graph in the form of solid line not poit, asterisk etc.

restart; epsilon := .1; Pr := 1; beta := .1; Sc := 1; S := 1; L := 20;
for i from -L while i <= L do;
a[i] := 1.0*i/L;
end do;
for i2 from -L while i2 <= L do;

fw := a[i2]; 

Eq1[i2] := eval(diff(F(eta), eta, eta, eta)+F(eta)*(diff(F(eta), eta, eta))-(diff(F(eta), eta))^2+S*(epsilon-(diff(F(eta), eta)))+epsilon^2);
Eq2[i2] := eval((diff(G(eta), eta, eta))/Pr-G(eta)*(diff(F(eta), eta))+F(eta)*(diff(G(eta), eta))); 
Eq3[i2] := eval(diff(H(eta), eta, eta)+Sc*(F(eta)*(diff(H(eta), eta))-beta*H(eta)));
IC[i2] := F(0) = a[i2], (D(F))(0) = 1, (D(F))(L) = epsilon, G(0) = 1, G(L) = 0, H(0) = 1, H(L) = 0;
dsys1[i2] := {Eq1[i2], Eq2[i2], Eq3[i2], IC[i2]};
dsol1[i2] := dsolve(dsys1[i2], numeric, output = listprocedure, range = 0 .. L);
dsol1x[i2] := subs(dsol1[i2], diff(F(eta), eta, eta));
dsol1y[i2] := subs(dsol1[i2], G(eta));
dsol1z[i2] := subs(dsol1[i2], H(eta)) end do;

for j from -L while j <= L do; 
g[j] := eval(-dsol1x[j](0)) end do;
with(plots); 

g6 := pointplot({seq([n/L, g[n]], n = -L .. L)}, symbol = asterisk, symbolsize = 15, color = red);
display(g6);

Please see the problem and correct as soon as possible. I am waiting your positive respone.

Muhammad Usman

School of Mathematical Sciences 
Peking University, Beijing, China

Hello! I try to make friends physics package and matrixes. But I am faced with difficulties. To be more specific, to consider a code:

with(Physics):
Setup(mathematicalnotation = true);
Coordinates(X);
Setup(tensors = A[mu](X));
PDEtools:-declare(A(X), p0(X), pm(X), pp(X), pt(X), U(X), m5(X))

And then I create a matrix:

pt := proc (X) options operator, arrow; Matrix(2, 2, [[p0(X), sqrt(2)*pp(X)], [sqrt(2)*pm(X), -p0(X)]]) end proc;

It displays as:

Why do p0, pp, pm become function only one variable x1?

Interestingly that maple understands the next matrix:

Nevertheless even for function only one variable derivative works fine:

And I can construct more complicated functions:

But why is only one variable?

The Möbius strip  Mobius_strip_rolling.mw

Variants :


The line and the curve on the surface.

Hi

When I try this maple retuurns FAIL and does not evaluate the expression.

is(seq(tm[i] < (1/6)*Diameter[rør][i], i = 1 .. 17));

tm is numbers in mm and diameter is also numbers in mm

Diameter[rør] := [273.05*Unit('mm'), 219.08*Unit('mm'), 168.28*Unit('mm'), 114.3*Unit('mm'), 273.05*Unit('mm'), 219.08*Unit('mm'), 1066.8*Unit('mm'), 60.33*Unit('mm'), 219.08*Unit('mm'), 168.28*Unit('mm'), 168.28*Unit('mm'), 141.3*Unit('mm'), 168.28*Unit('mm'), 114.3*Unit('mm'), 114.3*Unit('mm'), 168.28*Unit('mm'), 168.28*Unit('mm')]

tm := 8.982892831*Unit('mm'), 4.189790007*Unit('mm'), 3.913902969*Unit('mm'), 3.620745836*Unit('mm'), 4.482892831*Unit('mm'), 4.189790007*Unit('mm'), 8.793627806*Unit('mm'), 3.327643012*Unit('mm'), 4.189790007*Unit('mm'), 3.913902969*Unit('mm'), 3.913902969*Unit('mm'), 3.767378711*Unit('mm'), 3.913902969*Unit('mm'), 3.620745836*Unit('mm'), 3.620745836*Unit('mm'), 3.913902969*Unit('mm'), 3.913902969*Unit('mm')

please help me with this thank you

Edited.

Fellas

I'm wondering how to produce the graphic in the

https://en.wikipedia.org/wiki/Lazy_caterer's_sequence.

my attempt:
caterers.mw

Hi all,

I've an implicit equation f(x,y,z)=0 resulting in a PLOT3D containing ISOSURFACE structure.

p := plots:-implicitplot3d(f,....)

As stated in docs an ISOSURFACE type of plots can't be exported.

So, question is, has anyone an idea on how to write a file containing points (xyz) from my plot p? Or any other way to export the computed points?

Thanks and regards

JiPé

Recently, I came across an addendum to a problem that appears in many calculus texts, an addendum I had never explored. It intrigued me, and I hope it will capture your attention too.

The problem is that of girding the equator of the earth with a belt, then extending by one unit (here, taken as the foot) the radius of the circle so formed. The question is by how much does the circumference of the belt increase. This problem usually appears in the section of the calculus text dealing with linear approximations by the differential. It turns out that the circumference of the enlarged band is 2*Pi ft greater than the original band.

(An alternate version of this has the circumference of the band increased by one foot, with the radius then being increased by 0.16 ft.)

The addendum to the problem then asked how high would the enlarged band be over the surface of the earth if it were lifted at one point and drawn as tight as possible around the equator. At first, I didn't know what to think. Would the height be some surprisingly large number? And how would one go about calculating this height.

It turns out that the enlarged and lifted band would be some 616.67 feet above the surface of the earth! This is significantly larger than the increase in the diameter of the original band. So, the result is a surprise, at least to me.

This is the kind of amusement that retirement affords. I heartily recommend both the amusement and the retirement. The supporting calculations can be found in the attached worksheet: Girding.mw

I will try to explain with an example, lets say i have to solve 2 equations with 2 unknowns

P := solve({3*y+x, 2*x+3+y})

I would then like to do P[1] and P[2] to get the values, but instead it gives me "x=-9/5" which make me unable to use it for things like

P[1] + P[2]

Hope you all understand, and thanks for taking your time to read my problem 

It is well known that fsolve usually increases (internally) Digits in order to obtain the desired accuracy.

But in the following example, it seems that fsolve highly exaggerates :-)   

restart;
N:=40:
Digits:=100:
F:=expand(mul(x-k,k=1..N)):
f:=evalf(F):
S:=[fsolve(f,complex)];

Error, (in fsolve) Digits cannot exceed 38654705646

Note that the bug does not appear if e.g. F:=expand(mul(x-k-I, k=1..N)):