Here is a code

Maple Worksheet - Error

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

Download EQ.mw

A fragment of code

for b in extra_bcs do try print(b = 10^(-2)); res[b] := dsolve(dsys4 union {b = 10^(-2)}, numeric, initmesh = 2024, output = listprocedure, approxsoln = [omega2 = 0.1e-2, s(x) = cosh(upsilon*x)-cos(upsilon*x)-(cosh(upsilon)+cos(upsilon))*(sinh(upsilon*x)-sin(upsilon*x))/(sinh(upsilon)+sin(upsilon)), g(x) = sin(((2*n+1)*(1/2))*Pi)], abserr = 0.1e-1) catch: print(lasterror) end try end do; indx := indices(res, nolist); nops([indx]); res[indx[i]]; seq(subs(res[indx[i]](1), omega2(1)), i = 1 .. nops([indx]))

Hello everybody,

I have an interesting math problem, here it is:

Add the following operators: +, -, * in the middle of the following string 123456789 to get the final result: 2016

The operators can be added randomly at any place, it isn't necessarily placed in between single numbers.

To convince your result, one should provide the code or explain explicitly your method.

Have fun!!!!

hi.

how i can select or chose proper polynomials or another functions that attached boundary conditions at points zero and one , weakly or strongly satisfy??polynomial.mw

Download polynomial.mw

thanks...

hi.i calculate this integral numerically but after use this result in my differential equation which is involve f3(x), i enconter with error

i found that this problem is due to answer of this integtal.may i use another way to calculte it?as shown power in result are very large!!!

Download integral.mwintegral.mw

thanks..

I have written a code which generates a Gaussian like curve as a set of points and have written some basic commands to find several important quantities from the plot. The three of importance here are the peak position, peak height and Full Width at Half Maximum.

See the attached minimal working example maple worksheet.

It can find the peak position and the peak height no problem, but another quantity I want it to find is the Full Width at Half Maximum (FWHM). I use the aforementioned calculated values to find the left and right components of the FWHM but the fsolve command just hangs.

In the worksheet this is not evident but in the much longer full code which I run through the terminal and prints the values to a file, it begins the fsolve command and reaches a particular value and it just hangs. No amount of waiting time makes it continue the calculation.

However if I use an approximate integration scheme (such as Riemann sums) then the fsolve part executed perfectly. fslove seems to get stuck during the numerical integration step.

There is probably an easy answer to this problem which I am missing. Any help is appreciated.

fsolve_numerical_integration.mw

- Yeti

is there any command to plot ternarry plots that show the relationsh between three sets of data? For example check the link

https://en.wikipedia.org/wiki/Ternary_plot

Hi,

I am solving a system of differential equations with 2 variables. I can find numerical solution using dsolve with numeric option. I can also plot curves. But I also would like to extract data at time t0 and store into a file. I don't know how to extract numerical values from dsolve and store into a text file at various time, t0, t1, t2 etc. I would like to store data in tabular format with first, sceond and third columns are time, x and y respectively.

Just as an example, we can use

x'(t) = y(t), 

y'(t) = 6x(t) - y(t)

with x(0)=1 and y(0) = 2

Thanks.

I need to calculate Weyl scalar for a metric using null tetrad using debever package in maple 13. However, I am stuck at the defination of h (representing the covariant complex null tetrad). Is it the product of covariant null tetrad? I have worked it out by using covariant, contravariant and both covariant and contravariant null tetrad (like l_a*l_a, l^a*l^a, l_a*l^a), however, i am not getting the right result not even for the example given in the maple help for plane wave. please help me out that how should i define this h.

thanks,
suresh

I have a polynomial with parameter. I hope to solve the equation that every coefficient of the polynomial is zero.

For example

f(t):=(a+b+1)t+(a-b-1)

then I use the function solve(f(t),{a,b}),

I hope to get the solution to a+b+1=0 and a-b-1=0. However the output of Maple is {a = -(b*t-b+t-1)/(t+1), b = b}. How could regard t as a variable?

Thank you very much.

Dear All

Please see following:

Download loop.mw

Regards

Dear Maple users

I wanted to use the zip-command to muliply two lists with units. It works without units, but not with units:

If I add units to each entrance it works too, but not very convenient. How is it done with units in the best way?

Regards,

Erik

Hi,

I am designing a power transformer using Maple, and I am trying to solve for the minimum number of turns around my core for the desired effect. The equations to solve include numbers of turns (must be positive integers) and other constraints (positive floats).

To validate my worksheet, I am beta-testing it on an existing transformer, so I know of at least one solution that works. But when I submit the equations to Maple, it can't find the solution I know with integer solutions.

The equation is :

SOL := `assuming`([solve({N__2/N__1 = m__t, k__c*L__L(g__ap*Unit('m'), N__1)*I__M__pk = (1/2)*V__sec*T__res/m__t, g__ap <= 2*10^(-3), B__max(g__ap*Unit('m'), N__1, I__M__pk) <= B__max__core}, {N__1, N__2, g__ap, I__M__pk}, UseAssumptions)], [N__1::posint, N__2::posint, g__ap::positive])

And Maple's answer : 

{N__1 = 7.701193685, N__2 = 12.50000000*N__1, I__M__pk = (-1.855203719*10^9*g__ap^2+1.523613883*10^11*g__ap+5.590656409*10^6)*Unit('A')/(5.000000*10^6+2.43902439*10^8*g__ap), I__M__pk = (-1.100291349*10^11*g__ap^2+9.036307746*10^12*g__ap+3.315727980*10^8)*Unit('A')/(N__1^2*(5.000000*10^6+2.43902439*10^8*g__ap)), g__ap <= 0.2000000000e-2, 0. < g__ap}

Except I know there is a solution with N__1 = 6 and N_82 = 75. If I force n__1:=75 and solve again for the other variables, the solution is OK : 

X := `assuming`([solve({N__2/N__1 = m__t, k__c*L__L(g__ap*Unit('m'), N__1)*I__M__pk = (1/2)*V__sec*T__res/m__t, g__ap <= 2*10^(-3), B__max(g__ap*Unit('m'), N__1, I__M__pk) <= B__max__core}, {N__2, g__ap, I__M__pk}, UseAssumptions)], [N__2::posint, g__ap::positive])

And the answer :

X := {N__2 = 75., I__M__pk = -0.3759328777e-1*Unit('Wb')*(8.130081300*10^10*g__ap^2-6.676951220*10^12*g__ap-2.45000000*10^8)/(Unit('H')*(5.000000*10^6+2.43902439*10^8*g__ap)), g__ap <= 0.2000000000e-2, 0. < g__ap}

I am a bit puzzled about why Maple doesn't find this solution...

Thank you very much for your help.

Hello there,

I want to simplify this for a given rule in Maple

(-(1/2)*ib-(1/2)*ia+ic)*vc+(-(1/2)*ia-(1/2)*ic+ib)*vb+(-(1/2)*ic-(1/2)*ib+ia)*va

rule :  ia+ib+ic=0

A desired result should be 

3/2*ic*vc+3/2*ib*vb+3/2*ia*va 

but I can't apply this rule in Maple...  it seems like recursive and goes back again and again.

Can it break the recursive routine and make it as a desired result?

 Thank you

Hey guys,

I want to fit experimental data and I was wondering if there is a special PolynomialFit function for a surface.

My data consist of a X,Y, Matrix of densities and I want to have a function describing the surface of the values. On matlab the following code will do so:

[x, y, z] = prepareSurfaceData(temps, concs, densities);
ft = fittype('poly33');
fitresult = fit([x, y], z, ft);

Maybe that gives you a better view of what I want.

Best regards

I want to plot the position of Spherical pendulum. there are differential equation for spherical pendulum in spherical coordinates

sys := {((D@@2)(phi))(t) = -2*(D(phi))(t)*(D(theta))(t)*cos(theta(t))/sin(phi(t)),
((D@@2)(theta))(t) = (D(phi))(t)^2*cos(theta(t))*sin(theta(t))-9.8*sin(theta(t))}

with initial conditions

theta(0) = (1/2)*Pi, (D(theta))(0) = 0, phi(0) = (1/2)*Pi, (D(phi))(0) = 1

I tried:

eq := dsolve([((D@@2)(theta))(t) = (D(phi))(t)^2*cos(theta(t))-9.8*sin(theta(t)),
((D@@2)(phi))(t) = -2*(D(phi))(t)*(D(theta))(t)*cos(theta(t))/sin(phi(t)),
theta(0) = (1/2)*Pi, (D(theta))(0) = 0, phi(0) = (1/2)*Pi, (D(phi))(0) = 1],numeric)

how to change coordinates

x(t) = sin(theta(t))*cos(phi(t))
y(t) = sin(theta(t))*sin(phi(t))
z(t) = cos(theta(t))

and how to plot it from t=0 to 10?