Maple Questions and Posts

These are Posts and Questions associated with the product, Maple

I am trying to solve an equation by continuation method (one vairable and one parameter) containing more than 1000 terms and also hight exponents like 800. I want to get omega' values for different 'p' values.The maple file  is appended below. the link is maple_equation.mw

Many thanks in advance.

How do I find the constants in a solution containing whittaker functions?

the boundary conditions are:

c(x,0)=1

c(0,y)=1

[c'(1,y),x]=0

 

 

 

Sorry if this has been already posted.

 

When print() is invoked from a proc into a module, non-English characters are not properly displayed with Maple 18.

It works ok if it is invoked from within the workbook.

 

Example:
print("Están en perspectiva")

Put this sentence in a proc into a module and the character "á" wont be displayed

Output: "Est�n en perspectiva"

Any hint about how to treat this issue?

Thank you very much.

César Lozada 

 

 

To those who read this post.

 

I have a question about the property of local variables in a procedure.

Are names at the local variables in procedures, strings not names? 

If so, why can strings be evalated to have Integer, which is numbers for counting for continuing repetition? 

This is the code which searches for the maximum value. 

**************************************************

Max2 := proc()

local i, m :: string;
if nargs = 0 then
return -infinity
end if;
m:= args[1];
for i from 2 to nargs do
if args[i] > m then
m := args[i]
end if;
end do;
m;
end proc:
Max2(1,7,5,4,6,10,35,63.5,-10,5);

 ************************************************

type(a,name);

              this answer was true.

type(1, string)

              this answer was false, of course.

 

I limited the values of local variables to be string.

But, to the sequence 1,7,5,4,6,10,35,63.5,-10,5, any error messages wouldn't appear.

I hope any of you will give me an answer.

Thank you in advance.

 

taro yamada

 

 

 

 

 

Hi:

i follow the code newton raphson for solve system nonlinear ODE in maple,every body have code for it?

I have a worksheet. I edit some variables' value. I then execute the whole worksheet to see how the graphs change. But the graphs generated by display command do not appear. All other calculations update fine. 

To overcome this. I save worksheet with my new variable values. Close the worksheet. Reopen it. Execute it. And now the graphs appear fine.

 

Book1.xlsHelow ,

 I want to plot a gaph the data is store in excel sheet. thanks in advance

 

int((1-r^3+3*r^2-3*r)(r^3-3*r^2+3*r), r = 0 .. 1);
print(`output redirected...`); # input placeholder
/ 3 2
| / 3 2 \ / 3 2 \
int\-r\r - 3 r + 3 r/ + 3 r\r - 3 r + 3 r/

\
/ 3 2 \ |
- 3 r\r - 3 r + 3 r/ + 1, r = 0 .. 1/

¿How can I substitute multiple variables with the alsub command at the same time?

For example, if I want to substitute  x=x1, y=x2, .... into the expression f=x*y+x^2+.... using just one command

Hi everyone,

Command "discont" can return the discontinuous point of the function. 

In Maple Help, it says that multiple discontinuities may be expressed with _Zn, _NNn and _Bn but just show the _Zn case and the _NNn case.

 

Can anyone offer the _Bn case?

Thanks!

Hi everyone,

I have a question about surface fitting. I tried to follow the step of application "Fitting an Ellipse to Data" to fit the ellipsoid surface but got the incorrect result:

 

 

It seems that the convergence condition can be modified but I have no idea. 

The related Maple file is attached:

Ellipsoid_Surface_Fitting.mw

I'd appreciate any help on this topic. Thank a lot.

Some years ago member William Fish started a long discussion in part about a numeric integral involving high parameter (high oscillation) Bessel J0. That numeric integration task appeared in a Bitwise Magazine article.

At that time even obtaining numeric results involved extra effort such as handling real and imaginary components of the integrand separately, and requesting particular methods (sometimes hacked, to bump up the subinterval limit, for very high parameter values).

That led to a post where I showed that the result could be obtained quickly by using a fast compiled BesselJ (J0) from an external library along with a modified low-level call to a particular evalf/Int solver.

And sometime after that a numeric result for the real & imaginary split integrand became much more readily (if not quickly) available by using a new `maxintervals` option of evalf/Int to specify the maximal number of subintervals for the particular solver.

Maple 18 has its own compiled implementations of the Bessel functions for "hardware" (double) precision arguments. So now the numeric evaluations of the integrand are computed much faster.

Using Maple 18.00 on 64bit Windows 7 the same numeric results obtain in under a second, in a simple, single call to evalf,Int.

restart:

CodeTools:-Usage(
  evalf(Int(BesselJ(0, 50001*x)*x*exp(I*(355*x^2*1/2)), x = .35 .. 1))
                 );
memory used=9.28MiB, alloc change=32.00MiB, cpu time=437.00ms, real time=441.00ms, gc time=0ns

                           -8                 -8  
             3.181753502 10   - 7.798301124 10   I

restart:

CodeTools:-Usage(
  evalf(Int(BesselJ(0, 10000*x)*x*exp(I*(355*x^2*1/2)), x = .35 .. 1))
                 );
memory used=6.83MiB, alloc change=32.00MiB, cpu time=218.00ms, real time=211.00ms, gc time=15.60ms

                            -7                 -7  
             -2.007752340 10   + 4.275388462 10   I

 

Of course the ramifications of fast, compiled Bessel functions at double precision extend much farther than just this one example. But I like seeing the speed improvement in terms of a concrete example.

acer

What is the set of the points (x,y) s. t.

y^2+y^3+(y^3-x^2-3*x*y)^(1/4) <= 5*x*y ?

How to draw it with Maple?

 

 

Using the Fourier convolution theorem to solve f(t) =sin (t)

f(t)=R dJ(t)/dt+J(t)/C

R dJ(t)/dt+J(t)/C=f(t)

where f(t) is a driving electromotive force. Use the fourier transform to analyze this equation as follows.

 

 

Find the transfer function G(alpha)  then find g(t) .

 Thanks ....

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