I have a system of ode's

restart:with(plots):
eq1:=((diff(f(x),x$3)))+f(x)*diff(f(x),x$2)-a*diff(f(x),x$1)^2=0;
eq2:=(diff(g(x),x$2))+b*f(x)*diff(g(x),x$1)=0;
bc1:=f(0)=0,D(f)(0)=1,D(f)(5)=0,g(0)=0.5,g(5)=0;

dsolve can solve it easily.

sol:=dsolve(subs(a=0.5,b=0.5,{bc1,eq1,eq2}), numeric):

Now I was to use the numerical data from the sol in the following expression

Expr:=a*f(x)+b*g'(x)+c*f'(x)*g(x) # at x=1:

to make a table of this form a  b  c  Expr, where a, b, c vary simultaneously between 0 and 1 by 0.2 producing data for Expr.

Any suggestions? 

Hi everyone!

I have a question: what is the simpliest way to generate colorbar for spectrogram?

Now I use "valuesplit" to assign dependece "z"-value from color.

My programm. My test file: "Signal.txt".

filtered_spectrogram.mw

Signal.txt

P.S. I use Maple 2016.

Hi all,

How to calculate this integral:

for k>0,m>0

Int(exp(-(1/2)*v/k)*v^3*exp((1/2)*v/m)*Ei(1, -(1000*I)*v+(1/2)*v/m), v = 0 .. infinity)

I'm  tried to take advantage of with(IntegrationTools) but I failed

and and I got a strange result ,like this:

Integral.mw

Can somebody execute this code on a powerful comp and report the result in MaplePrimes? That would be kind of her/him.

Download want_for_execution.mw

In the TransformTetrad command we can use some parameters, including nullrotationwithfixedl_. However, the nullrotationwithfixedl_ parameter requires another parameter E. How do I enter parameter E?

Thanks,

Denis.

Dear Maple experts,

I would like to teach volume of solids generated by revolution of an area between two curves by washers & cylindrical shell methods uisng Maple technology to my students. In this regard, I request the Maple experts to provide easy commands to meet my requirement.

With thanks & best regards.

Mr.M.Anand

Associate Professor in Mathematics

i could have sworn that when itegrating a gaussian maple will write it in terms of the erf functions... but i end up with:

gg:=A * exp( - ( (t - t0) / (tau) )^2 );
val1:=int(gg, t=-x0..x1) assuming t0::real, tau::real, x0<x1, t0>x0, t0<x1, x0::real, x1::real;  #or with no assumptions
 

the results is just gg unchanged... Doing:

convert(val1, erf)

does not help. I can set t0 (or transform it away), and it works, but I was hoping maple would not require this. 

Any thoughts how to help maple with this?

Mathematiaca can read my mind without issues:

Is this a bug?

hypergeom([1, -1, 1/2], [-12,-3], 1);
Error, (in hypergeom/check_parameters) function doesn't exist: missing appropriate negative integers in the first list of parameters to compensate the negatives integer(s): [-3], found in the second list.
 

Yet this hypergeometric series terminates and Maple should be able to handle it, at least according to the Maple help page (the second rule below applies, yet the numerator has a smaller absolute value, so the first rule below applies).

If some   n[i] is a non-positive integer, the series is finite (that is,   F(n, d, z)  is a polynomial in    z).
If some  d[j]  is a non-positive integer, the function is undefined for all non-zero  z, unless there is also a negative upper parameter of smaller absolute value, in which case the previous rule applies.
 

Interestingly, the Wolfram Mathematica app can evaluate this to 311/312.

hi.how i can solve or fsolve this equations?

i can not with fsolve?

thanks alot

SOLVE.mw


Maple Worksheet - Error

Failed to load the worksheet /maplenet/convert/SOLVE.mw .
 

Download SOLVE.mw

I would like to set a metric in its contravariant form before its covariant form but Maple does not do this operation.

Thanks!

I have this H(alpha,beta,eta) con ‡uent hypergeometric function, which I can easily adopt in Mathematica like this

Hypergeometric1F1[( (\[Alpha] + S \[Beta]))/\[Beta]^2, 
 1 + ((\[Alpha] + S \[Beta]))/\[Beta]^2, -\[Alpha] ((
   E^(-\[Beta] \[Eta]))   )/\[Beta]^2]

But when I try to input this in maple using the built-in `hypergeom` it gives an error.

hypergeom((S*lambda2+alpha)/lambda2^2, 1+(S*lambda2+alpha)/lambda2^2, -alpha*exp(-lambda2*eta)/lambda2^2)

Any suggestions?

Hi all,

I have this equation that I can not get all solutions symbolically:

restart:

eq1 := cos(lambda*ln(r1))*cos(lambda*ln(r2))+sin(lambda*ln(r1))*sin(lambda*ln(r2))-1 = 0:

solve(eq1, lambda, allsolutions) assuming r1>0, r2>0, r2>r1

when r1:=1: r2:=2: I get the solution

2*Pi*Z/ln(2)

when r1:=1.1: and r2:=2.1: # no solutions

How to get symbolique solution

Thanks

I'm trying to approximate the solution of an IVP using Euler's method in the InitialValueProblem command and I keep getting this error (see attached worksheet). Can someone explain why? Thanks!
 

Download ivp_error.mw

I have noticed the second item in Description in

http://www.maplesoft.com/support/help/Maple/view.aspx?path=convert/binary

The item is: 

“The binary number is returned as a base 10 number consisting of the digits 1 and 0 only.”

Does the existence of this item mean the following behavior will not be corrected ? ("10^(-6)" in the following should be "2^(-6)" .)

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

When trying to perform the following:

p1 := proc (x, y) if x^2+y^2 <= 1 then x*y-y^2 else 0 end if end proc;
plot3d(p1, x = -1 .. 1, y = -1 .. 1);
Error, (in plot3d) expected ranges but received x = -1 .. 1 and y = -1 .. 1
 

I get this strange error message. To the best of my knowledge x and y ARE provided as ranges. What am I missing/not understanding?

If I omit the ranges in plot3d Maple returns a correct plot, but the default range (-10 .. 10) does not display sufficient details