I have the following fuction in Laplace domain,

restart:with(plots):with(inttrans):

u:=Pi^4*s3^(alpha-1)/((s1^2+Pi^2)*(s2^2+Pi^2)*(-s1^2+Pi^2*s3^alpha-s2^2))-Pi*s1*s2^(alpha-1)/(s3*(1+s2^alpha)*(-s1^2+Pi^2*s3^alpha-s2^2))-Pi*s1*s2^(alpha-1)/(-s1^2+Pi^2*s3^alpha-s2^2);

Where, s1, s2, s3 are the Laplace variables.

x1:=invlaplace(u, s1, x);

This worked. But the next two doesn't work.

y1:=invlaplace(x1, s2, y);

uu:=invlaplace(y1, s3,t);

Even, I tried to plot the unevaluated invlaplace but no luck.

alpha:=1:t:=1:
plot3d(uu,x =1..2, y=1..2);
 

Am I missing something?

Dear all,

I have the following question, this code:

restart:
with(DifferentialGeometry):
DGsetup([w1,w2],N):
eq1 := ExteriorDerivative(w1);  
eq2 := ExteriorDerivative(w1) &wedge ExteriorDerivative(w2);
eq1 &wedge eq2;

Gives the error:
Error, (in DifferentialGeometry:-Tools:-DGzero)  given degree, 3, exceeds that of frame dimension, 2

Unfortunately, I am not so familiar with differential geometry but as far as I know dw1  (dw1  dw2) = 0 should be correct.

Thank you for your help
best
baustamm1

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

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

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)):

How to pdeplot Curl(A(x,y,z))=0 in maple

it has A1(x,y,z) , A2(x,y,z) and A3(x,y,z)

Hi all,

I have a partial differential equation similar to the following:

The solution is that f is identically equal to 0.

However, I am having trouble solving this equation in Maple. I type the following:

pde := diff(f(x, y), x)+diff(f(x, y), y) = f(x, y)+f(x, 0);

bv1 := f(x, 10) = 0;

bv2 := f(10, y) = 0;

solution := pdsolve(pde, {bv1, bv2}, numeric, time = x, range = 0 .. 10);

When Maple tries to evaluate the last expression, I get the error

Error, (in pdsolve/numeric/process_PDEs) PDEs can only contain dependent variables with direct dependence on the independent variables of the problem, got {f(x, 0)}

It seems to have difficulties with the expression "f(x,0)". Is there some trick to typing this in a way that makes Maple interpret it correctly?

Edit: I encounter the same problem, when I try to solve the ODE f'(x) = f(x) + f(0), where f(10) = 0.

Best regards.

Is there a method to relate groebner bases with monomials ideals

Hello everyone,

For some reason, the rising edge block is not working how it is supposed to.

The component decription is as follows: "

The Rising Edge component triggers a Boolean expression, true, in the output, y, when a rising edge is detected at the input, u.

I am applying a step signal. (red waveform)

and this is the probe's measurement:

Why is it not detecting the rising edge?

Thanks,

John.

I attempt to understand is it possible whether to calculate the next expression by means of mathematica:

where

{,}- anti-communicator;

 a=0,1,2,3;

\tau^{0}-unity matrix; \tau^{i} - Pauli matrix;

and:
 

 
finally - Levi-Civita symbol; -Hermitian conjugation.

Thank you for your kind replies .

Hi ,

I have recently got to know this software and its capabilities and was wondering if I can use it to start an initial systems design for an E-scooter as a first step (virtual validation). then feed this data to a designer which will design and cooperate with an engineer to realise the design again on this platform.

SO i have the range of my scooter , the weight it carries , the enviroment's average topography which i will be simplifying it at the first step to a 15% hill climb , and finally some dynamic/static restrictions... which i hope ican build upon . like adding chasis loads and analysis to data.

I want it to give me the cell number of the batteries , verify the loads and give me a electric-motor description . 

this was the road map.

Thank you for your kind replies .

Is there a way to change the numeric formatting of 'Scientific' to use a cdot instead of a cross to represent multiplication?

Is there a problem with MaplePrime web site?   All my questions for the last 4 years, and answers are no longer available. All gone. I posted a question early today about sin(x) calling. one hr after that, I noticed all my questions and answers gone.

When I go to my user profile, it says I have zero questions, zero answer and zero post for the last 4 years. All the answers to my questions also got deleted, which is a shame if this happened. They have many useful information.

Any one else affected by this?

I have a need to calculate base 2 math as would be done in an integrated circuit. Math will be done using 15 bit 2's complement mantissa and 8 bit exponent. (the exponent is always assumed to be negative) We need to perform multiplication and addition, where each internal operation is represented by such a number.

The goal is to best represent the errors associated with such calculations and export the resulting code to a hardware description language for implementation on an integrated circuit.

Is there a package in Maple that can do that? Any advice on how te proceed?

for the simple ODE:

dsolve(26*(diff(y(x), x$4))-50*(diff(y(x),x$2))-2*y(x) = 0)

dsolve produces strange solution as below:

in this solution the forth function is wrong and it would be as below:

_C4*exp((1/26*I)*sqrt(26*sqrt(677)-650)*x)

can you explain this problem???

please help me :((((