Hi,

I have an inverse I solved for with RootOf, which I transfrom and then try to numerically integrate the transformation. I get the following error: Error, (in convert/radical) too many levels of recursion

Integrating the inverse itself works, it is after applying the transformation 1/(1+x²) that I get the issue. Eventually I want to integrate something less simple, but here the problem already starts. 

Thanks for the help! Its for science! 
 

Download recursionerror.mw

Hey all together,

this is my first question in this community and it is maybe a very simple one:

If I have a given matrix. How can I process individual elements with an mathmatical operation?

For example, I have a diagonal matrix and want to get a matrix in which every non-zero element is the square root of the inverse of its former element.

Has someone an idea?

Thank you very much!

hello , there , i want ask a Question ,

i have a vector result n hier , and there is a long part with ^1/2 (like unter) , which is not defined before , just from compute ,i want to replace this part with A, and have tried to use subs , but it didnt work . 

And i have tried to define it before compute, and then use subs , aber it also didnt work .

so how can i replace or define this part in the result?

thanks

Dearz

I draw multiple graphs in singal coordinate with same line style. I don't know how to change the line style and color for g[1], g[2] and g[3] becuase of loop. Please some fix my problem to give them different style and color.

graph.mw

Hi all, 

Is there anyone who could solve this equaiton? I think there is no solution!!!!

Download Solve_Equation.mw

Download DiracAlgebraWithIdentityMatrix.mw

Edgardo S. Cheb-Terrab
Physics, Differential Equations and Mathematical Functions, Maplesoft

Maple function code:

GetAngle := proc(opp, hyp)
local theta;
theta = arcsin(opp/hyp);
evalf(180/Pi*theta);
end proc:
GetAngle(4,5)
                       57.29577950 theta
Matlab code:

function [outputArg1,outputArg2] = GetAngle(opp,hyp)
    theta = asin(opp/hyp);
    outputArg1 = 180/pi*theta;
end

> GetAngle(4,5)

ans =

   53.1301

Ditto same code from Maple programming guide 2017:

Why is there a difference in the answer, am I coding it wrong? I mean any syntax errors that I am not following?

I need find CPU time for a set of mathematical calculations,  what is the best method in maple 18?

Dear all!

I am facing problem to find the solution of system of linear equations as attached for different values of alpha, please the see the attachment and fix my problem

Equations.mw

Thanks in advance

Hi there,

I know for a given 2x2 system of differential equations, it is possible for maple to plot a phase portrait on x-y plane (or a graph with directions and arrows).And this is also possible in a 3x3 system by choosing 2 variables / the plane of projection by including the code scene=[x(t),y(t)] (on x-y plane) .

My question is:

given a system of 3x3 differential equations,like

dx/dt = f(x(t),y(t),z(t))

dy/dt = g(x(t),y(t),z(t))

dz/dt = h(x(t),y(t),z(t)),

how could I produce a 3D vector field of the system? (with arrows)

Thanks!

Good day!

I am working to solve a double series (LP  minimization) problem of the form 

z = add(add(x[i,j]*y[i,j]*z[j], j=1..6), i=1..3).

However, this returns a set [ ]. 

Since LPSolve does not operate on a set (removing the brackets manually will enable LPSolve to obtain the solution), can anyone suggest what is wrong with the structure of this z-equation? x, y are matrices and z is a column vector.

Thanks!

If I insert a hyperlink to a website, it works fine when I'm in Maple, but when I export my Maple to pdf, the hyperlink is not clickable anymore.

I've tried using both Windows' "Microsoft Print to PDF", Maple's own "Export to PDF", "cutepdf" as well as MacOS "Save to PDF". Is there a way of doing this?

Best wishes

Hey any one can help? I calculated the characteristical Polynom of my Matrix M:

-(lambda-2)^2*(544-lambda^9-328*lambda^7-16*cos(x-y)+6*cos(x-y)*lambda+6*cos(x+y)*lambda-408*cos(y)*lambda^2-408*cos(x)*lambda^2+540*cos(y)*lambda+540*cos(x)*lambda-28*cos(y)*lambda^4-28*cos(x)*lambda^4+152*cos(y)*lambda^3+152*cos(x)*lambda^3+2*cos(y)*lambda^5+2*cos(x)*lambda^5-256*cos(y)+17232*lambda^2-256*cos(x)-7852*lambda^5+17768*lambda^4+2088*lambda^6+28*lambda^8-16*cos(x+y)-23632*lambda^3-5844*lambda)

now I want to solve the second part of the polynomial with lambda^9 but maple gives me the RootOf-function

_Z^9-28*_Z^8+328*_Z^7-2088*_Z^6+(-2*cos(y)-2*cos(x)+7852)*_Z^5+(28*cos(y)+28*cos(x)-17768)*_Z^4+(-152*cos(y)-152*cos(x)+23632)*_Z^3+(408*cos(y)+408*cos(x)-17232)*_Z^2+(-12*cos(x)*cos(y)-540*cos(y)-540*cos(x)+5844)*_Z+32*cos(x)*cos(y)+256*cos(y)+256*cos(x)-544

How can I simplify this expression to solve over lambda.

purpose is to plot all the eigenvalues.

Thank you in advance.

Hello,

Why does the following work as expected...

f__c := proc (x__0, y__0) options operator, arrow; piecewise(x__0^2+y__0^2 <= 1 and (x__0-1)^2+y__0^2 <= 1 and x__0^2+(y__0-1)^2 <= 1 and (x__0-1)^2+(y__0-1)^2 <= 1, 1, not (x__0^2+y__0^2 <= 1 and (x__0-1)^2+y__0^2 <= 1 and x__0^2+(y__0-1)^2 <= 1 and (x__0-1)^2+(y__0-1)^2 <= 1), 0) end proc

But the following does not?

cnd := x__0^2+y__0^2 <= 1 and (x__0-1)^2+y__0^2 <= 1 and x__0^2+(y__0-1)^2 <= 1 and (x__0-1)^2+(y__0-1)^2 <= 1
f__c := proc (x__0, y__0) options operator, arrow; piecewise(cnd, 1, not cnd, 0) end proc

(Sorry about the lack of formatting, the forum insists my Maple syntax is invalid)

The first one produces the expected result, x__0 and y__0 are treated as variables in the condition (i.e. f__c(a, b) returns the same piecewise function with x__0 replaced with a and y__0 replaced with b); the second one does not (i.e. f__c(a, b) returns the piecewise function, still with x__0 and y__0 in the condition, and never gets evaluated).

Dear all

I have a system of PDes, the code i think it's well writte but when I use pdesolve i have no solution obtained.

Maybe I must add something else

Many thinks

sysPDes.mw