How can I produce the same output with something like alphadeg := alpharad * 180/Pi?

T := proc (p, q, R) alpharad = evalf[5](arccos((1/2)*(p^2+R^2-q^2)/(p*R))), alphadeg = 180*evalf[5](arccos((1/2)*(p^2+R^2-q^2)/(p*R)))/Pi end proc;
T(3, 4, 3.75);
           alpharad = 1.2515, alphadeg = 71.70566805

When I try alphadeg = alpharad * 180/Pi I get
Error, illegal use of an object as a name
 

Thanks! Les    AB59_20170205_Post.mw

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.

Hi! I have a variable polynomial expression and I want to cut off all the terms of order 3 and more, for every product of variables.

For example consider the polynomial P = x + y + a*x^2 + b*x^3 + c*x*y + d*x^2*y + e*x*y^2 + y^2, I want an operation who returns me a*x^2 + c*x*y + y^2

(terms for which the sum of exponents in x and y exceeds or less two are being deleted)

Is it possible?

Is there a way to define forms with anticommuting functions? I've tried without success:

> with(Physics):
> Setup(anticommutativeprefix={alpha,beta}):
> with(DifferentialGeometry):
> DGsetup([x, t], M):
> (alpha*dx+beta*dt) &wedge (alpha*dx+beta*dt);

                             (0 dx) ^ dt

> (f*dx+g*dt) &wedge (f*dx-g*dt);

                           -(2 f g dx) ^ dt

Thanks. Jose Carlos

hi..

how i can write this line ''for'' in maple?

thanks..

for.mw
 

Download for.mw

If binary constraints are imposed on an optimization problem and LPSolve presents a solution, is it possible to extract the variables that have zero or one assigned to them? This would be most useful if there are many variables, for example...

If a solution is returned that looks like ...

[x[001]=0, x[101]=1, x[201]=0, x[301]=1, ....], how can I filter those solutions that equal zero?

Thanks for reading!

Is there a method to relate groebner bases with monomials ideals

How to plot magnetic field of maxwell equations like vector field

I am debugging a Maple program (and I cannot contact its author). Allegedly, the program ran under some old version of Maple, but it does not run under my Maple 2015 or Maple 9. I am trying to make it run under Maple 2015. I found a place where the program does not do what it is expected to do, but don't know how to make it do what I want:-)

I inserted a DEBUG statement at some place in the program, and the debugger window opens when the program comes to that statement. I execute  the following statement in the debugger:  traperror(Groebner:-NormalForm(g,AA,matermorder)); if I get some benign result, such as 0, I push "continue" in the debugger, and the program runs until it gets to the DEBUG statement again. I repeat these two operations several times until the traperror statement gives the following: polynomials must be members of the algebra" (my comment: only one quotation mark).

So I would like to amend the program to process the exception differently from how it is done now, but I don't know how to get access to the result of the traperror statement. For example, when I am trying to execute the following operators in the debugger: adebug:= traperror(Groebner:-NormalForm(g,AA,matermorder));adebug; , I only get the following diagnostics: Warning, extra characters at end of parsed string  So I don't understand what adebug contains and how I can introduce some logic based on the contents of adebug to handle the exception differently.

I suspect I am missing something simple due to my lack of experience with Maple. I tried to put the result of traperror into a parse statement, but did not get any satisfactory results.

Thank you 

hi .in substuting in ode equation i encounter with error

Error, (in eval/diff) invalid input: diff received (f1[i+1, i]-2*f1[i, i]+f1[i-1, i])/h^2, which is not valid for its 2nd argument

please help me

thanksh_2.5_eq4.mw
 

Download h_2.5_eq4.mw

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.

Hello all

I am new to Maple, and I am solving a system of two coupled partial differential equations using pdsolve, but I am having a hard time retrieving the solution evaluated at some point from the output. The output of pdsolve is a module, which appears to have different "methods" on it, including "plot3d" and "value". I can easily get a plot of my solution by using plot3d, but I don't know how to get a meaningful value out. For instance, if my solution is (f(x,y), g(x,y)), I would like to define H(x,y) = (f(x,y), g(x,y)), and be able to type H(10,10) into Maple to have my solution evaluated at that point. The result should be (1,1).

Here is a toy example:

Best regards.

hello im currently working on a project and im fitting some non-linear data with the follwing model:

model:= 1.*10^5*exp(-t*k-*t/B)

where B and k are the unkown parameters.

i have the following data:

X=<0,2,4,6,8,10>

Y := <100000, 86089.76983, 74114.4849, 63804.98946, 54929.56828>

if i do the fit like this: fit(model,X,Y,t) i get a fit that looks like this:

100000*exp(-0.520664970792415e-1*t) which i alright. however when i try to get the parameters i get something like this

fit(model,X,Y,t,output=[parametervalues])

[B = .999563650781966, k = -.948370042622550] - when i define k=0.05 however i get [B = 483.910474528817], which is the right parameter.

insereting the two different sets yields:

1) k=0.05, B = 483.910474528817 -> 100000*exp(-0.520664970792415e-1*t) (good aprox to the fit)

2) B = .999563650781966 and k = -.948370042622550 -> 100000*exp(-0.5206649794e-1*S) (way off)

how is this possible anyone able to help, been sitting with this for days now?

I have to calculate a sort of trend line, but I don't know how it works with maple.
I tried with Excel.

Do you think the method is right? How can I replicate it on maple?

Thanks in advance

Hi Everyone!

The differential geometry packege of Maple allows one to compute Lie brackets of vector fields in coordinates.

I wonder if it is possible to compute Lie brackets in a more abstract fashion. For instance, I wish to define X,Y,Z as elements of a Lie algebra and a,b,c to be constants. For them I want to compute (= expand and simplify) expressions like [[aX+bY,cZ],[cY,[bX+cZ]]] using only basic properties of Lie brackets (skew-symmetry + Jacobi identity), without going to coordinates. Is it possible?

Thanks,

Dmitry