Hello,

I would like to obtain all the solutions of a equation.

Here an extract of my code:

v:=unapply(H*sin(w*t),t);
L:=0.080;
H:=0.020;
Vf:=0.3;
w:=10;
fsolve(v(t)=0,t=0.5..2);

How can I do to obtain all the solutions of the equation in the wanted interval ?

I'm not fixed to use fsolve function.

Thank you for your help

 Can anyone explain me how to use the next feature that you can find in ?dsolve,numeric,events,Round-off and simple triggers or refer me to a previous answer that explain this:

   This is primarily desired to be able to apply events for an ODE system that has been separated into disjoint cases dependent on the values of particular triggers (in which case you always want to use a form that provides the values just past the trigger point).

 Specially how to separate the ODE system into disjoint cases. Thanks in advanced.

Hello all,

I am trying to create a matrix throgh a procedure but unfortunately I could not find how to define an empty matrix in Maple. This is how my procedure looks like,

Initial_Matrix := proc (BC::list, n, BP::list)
local M::Matrix, i;
M:=[][];
for i from 1 to numelems(BC) do
M:= <M,function_coeffs(BC[i], n, BP)>;
end do;

where the procedure function_coeffs returns a row vector. Logically, it should keep adding rows function_coeffs(BC[i], n, BP) to the emty matrix, but its not happening. Please help me out.

Thank you for your time.

Is there a help page which explains why braces provide the partial text evaluation in this code?

RopeLen := 30;RopeAddLen := .5;

plots[textplot]([1, 1, typeset("%1", (({(1/2)*RopeLen}+{(1/2)*RopeAddLen})^2-{(1/2)*RopeLen}^2)^(1/2))])

I have the following equation:

Diff(W(t), t) = -q*V*(sin(Phi)-sin(Psi[s]))/(2*h*Pi);

I solve it for rhs() = 0:

soln := solve([rhs((2)) = 0, Phi < 2*Pi], [Phi], allsolutions = true,explicit);

This works and I get this result:

Now I want to get the first zeros, which occur for _Z1 and _Z2 equal to 0. So I substitute:

subs(_Z2=0,(3));

and get

In other words, the substitution did not work.

The original problem is embedded in a larger sheet created with Maple 15 and there it does work. It fails on Maple 2015.2. I then pulled out the relevant pieces to make this example demonstrating the problem (see the attached sheet, which has some of my other (unsuccessful) attempts to diagnose what is going on). It seems like the created variables _Z1 and _Z2 are somehow not recognized at all.

The only way I can get the _Z2 terms out is to substitute 2=0. This is really too icky to seriously consider, though.

Anyone has seen this before?

FWIW: Maple 2015.2 on Mac OS X 10.10.5.

Thanks,

Mac Dude

Assumptions_test.mw

In addition to the Maple 2015.2 and MapleSim 2015.2 updates for Mac, we have just released updates to both Maple and MapleSim for Windows and Linux.

Maple 2015.2a provides a fix for the sum bug reported here.

MapleSim 2015.a provides a variety of interface improvements, and updates to the MapleSim Battery Library and MapleSim CAD Toolbox.

For Mac users, these improvements are included with the Maple 2015.2/MapleSim 2015.2 updates.

All updates are available through the Check for Updates system, and are also available from our website on the downloads section of our website.

eithne

We have just released updates to Maple 2015 and MapleSim 2015 that fix the problems on Mac OS X 10.11 (El Capitan).  If you want to use the new OS, you should update your products.

Updates are available through Check for Updates and from the Downloads section of our website. See Maple 2015.2 and MapleSim 2015.2 for details. MapleSim users, please note that this update also gives you all the new features in MapleSim 2015.2.

If you are using earlier versions of these products, please read the  Maple and MapleSim on Mac OS X 10.11 FAQ for more information about your options.

eithne

This is not actually a question, but an interesting problem found in the recent book (2nd edition, 2015):
Mathematica®: A Problem-Centered Approach
by  Hazrat Roozbeh
Springer

I hope that you will enjoy the problem too.

Define the functions f, h : N --> N by
f(n) = the sum of the squares of the digits of n; e.g. f(25) = 2^2 + 5^2 = 29.
h(n) = min {f(n), f(f(n)), f(f(f(n))), ... };  e.g. h(7)  = min{49,97,130,10,1} = 1.

A natural number n is happy if h(n) = 1.
Find all the happy ages, i.e., happy numbers up to 100.
Conclude that happy ages are mostly before one gets a job or after retirement!

Hello,

I would like to plot coupled elliptic parametric curves.

I have a problem in the for loop in my code. The index i of the phi variable is not incremented.

Here my code:

for i to 4
do
u[i]:=t->L/2*cos(w*t);
v[i]:=t->H*sin(w*t+phi[i]);
end do;

The result looks like this :

u[1](t) -> - L cos(w t)
v[1](t) -> H sin(w t + phi[i])

u[2](t) -> - L cos(w t)
v[2](t) -> H sin(w t + phi[i])

u[3](t) -> - L cos(w t)
u[3](t) -> H sin(w t + phi[i])

u[4](t)  -> - L cos(w t)
u[4](t)  -> H sin(w t + phi[i])

And i would have prefered :

u[1](t) -> - L cos(w t)
v[1](t) -> H sin(w t + phi[1])

u[2](t) -> - L cos(w t)
v[2](t) -> H sin(w t + phi[2])

u[3](t) -> - L cos(w t)
v[3](t) -> H sin(w t + phi[3])

u[4](t)  -> - L cos(w t)
v[4](t)  -> H sin(w t + phi[4])

Do you have ideas how I can obtain iteration on my phi variable ?

Thank you for your help.

Can some one help me " How to conert a three or four coupled equation by using non dimensions variable "

Hi,

I have an issue calculating an electronics circuit with Maple, using units. I have a current source that I know, and I want to determin the voltage in a capacitor by solving an ODE (except that the current source is defined piecewise). And to make sure I have all the units and scales right, I use the standard unit package. All my variables have their units defined.

Except that Maple doesn't want to solve the equation. It seems to me that it assumes that the function I am trying to solve is unitless, and therefore refuses to solve. 

V__out := 3*Unit('kV');

C__out := 2*Unit('nF');
R__blead := 520*Unit('`k&Omega;`');

I__fly := proc (t) options operator, arrow; Unit('A')*piecewise(t < 3.25*Unit('us'), (1+(-1)*t/(3.25*Unit('us')))*.2, 0) end proc;

dsolve({I__fly(t*Unit('s'))-V__C(t*Unit('s'))/R__blead = C__out*(diff(V__C(t*Unit('s')), t)), V__C(0*Unit('s')) = V__out}, V__C(t*Unit('s')));
Error, (in Units:-Standard:-+) the units `A` and `S` have incompatible dimensions

Is there a way to make Maple assume the unit of what it's trying to solve ? I need it to understands that V__C is in Unit('V') ...

Thanks

Hi,

what i have to calculate in Maple for q=Mises-Stress and the third invariant of deviatoric stress as r???

It is for:

Link:
http://www.egr.msu.edu/software/abaqus/Documentation/docs/v6.7/books/stm/default.htm?startat=ch04s04ath116.html

hi...amount of Determinant  is infinity?how i can remove this bad calculation ?

thanks...mode_shape2.mw

hi .by changing amount of variable such as '' f '' or 'D5 ' in input data, not changing  in final result!!!!please chek attached file 

thanksX4.mw

Hello,

I try his code:

for i to 6 do u[i, j] := (u[i-1, j]+u[i+1, j]+lambda*(u[i, j-1]+u[i, j+1])+sigma(h, r[i+1])*(u[i+1, j]-u[i-1, j]))/mu end do;

 
Error, too many levels of recursion.

I want to the  results of the analytic equations, for example:

                                                          
 u[1,j]= (u[0, j] + u[2, j] + lambda (u[1, j - 1] + u[1, j + 1])                                                       

      + sigma(h, r[2]) (u[2, j] - u[0, j]))/mu

.

.

.

.
Regards.