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    Mathematica Plotting data in mathematica

    hi i upload the data.txt file . how to plot it? i tried ListPlot but it did not work thanks
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    Mathematica Plotting data in mathematica

    hi i compile a c++ program and after compiling it gives me a txt file which contains about 50000 points. how i can plot these points in mathematica? thanks
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    Mathematica Problem in NDSolve in mathematica

    i can not understand how did you do that. please tell me how?
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    Mathematica Problem in NDSolve in mathematica

    thanks that was amazing! how you guess that?
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    Mathematica Problem in NDSolve in mathematica

    i want to solve a large system of coupled differential equations but i get this error NDSolve::nlnum: i attach the notebook in zip format. what is the problem? thanks
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    Mathematica Integro-Differential Equation with mathematica

    hi how can i solve a system of Integro-Differential Equations in mathematica numerically or analytically? thanks
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    Mathematica How to define local variables and constants in mathematica

    hi suppose i run Two notebook and in each of them i have matrix A and Constant B and a function C in each notebook these things have the same name. if in notebook 1 i assign B=10 then in notebook 2 B is 10 too , which is not my desire. how can i define these constants and matrices and...
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    Mathematica Running simultaneous computation in mathematica

    Bill Simpson thanks for your comments. jackmell i do not know how to do that. however i think i should define the results of computation in new variables. for example if after a computation i obtain a matrix i define it for another variable.
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    Mathematica Running simultaneous computation in mathematica

    hi when i run a heavy computation on mathematica in the same time even if i want to calculate 2+2 , mathematica does not calculate it until calculating of heavy computation finishes. why? another problem is that when i do a heavy computation and obtain results , after closing mathematica...
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    Mathematica Problem with superscript and subscript in mathematica

    hi i want to sum over two indices i and j . the elemet that i must sum is (x^(i,j))-i that is x has superscript i,j and subscript i. but in mathematica it gives me error. here is the notebook : http://www.mediafire.com/?novtz7t0liu9u78 [Broken] thanks (:
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    Mathematica Parametric plot in mathematica

    hi i solve numerically two coupled equation and obtain two function x[t] and y[t]. how i plot x[t] versus y[t] so that horizontal axis to be x[t] and vertical axis to be y[t]. here is the notebook of mathematica http://www.mediafire.com/?g4sa3zi630vi8nl [Broken] thanks
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    Mathematica Solving equation with mathematica

    it gives me x=25.16 which is incorrect!
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    Mathematica Solving equation with mathematica

    hi i want to solve this equation a/x=Cosh[b/x] i set a=1 and b=5 and use NSolve code but mathematica say it can not solve it. but with maple i get real and imaginary parts. 1-is there another method to solve this equation numerically? 2-can this equation be solve for arbitrary a and b...
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    Mathematica Solve matrix differential system and asymptotic solution in mathematica

    for this problem i use Map[(#[t] /. (soln[[1]])) &, dd, {2}] and it works. but still have problem 1
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    Mathematica Solve matrix differential system and asymptotic solution in mathematica

    hi i do not understand what you mean. can you write an example for this two problem? 1-Numerically solving equation (d/dt)A=B . which A and B are n by n matrices with some initial condition for example A[0]=C. after solving numerically i need to take partial trace and plot the resulting...
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    Mathematica Solve matrix differential system and asymptotic solution in mathematica

    hi suppose initial condition is d[0]=IdentityMatrix[4] and initial time =0 and final time 11. and another question: when i use n = 4; d[t_] = Array[Subscript[w, ##][t] &, {n, n}]; dd = Array[Subscript[w, ##] &, {n, n}]; soln = DSolve[LogicalExpand[d'[t] == p], Flatten@dd, t] the...
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    Mathematica Solve matrix differential system and asymptotic solution in mathematica

    hi how i modify below codes to solve problem numerically? n = 4; d[t_] = Array[Subscript[w, ##][t] &, {n, n}]; dd = Array[Subscript[w, ##] &, {n, n}]; soln = DSolve[LogicalExpand[d'[t] == p], Flatten@dd, t] thanks
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    Mathematica Solve matrix differential system and asymptotic solution in mathematica

    thanks it works. is there any reference for this code? Limit[Map[(#[t] /. (soln[[1]])) &, dd, {2}], t -> Infinity] i want to understand the job of any part of it. like #[t] and /. and (soln[[1]]) and (soln[[1]]) and dd (which is the solution of equation) and {2} (why it is 2 not...
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    Mathematica Solve matrix differential system and asymptotic solution in mathematica

    i manage to take limit .error was for lack of some assumptions on variables like positivity and .... but i now have another question how i take limit from all 16 solution of the equation as a whole . without taking limit individually? 1-is there any method to take limit from all 16...
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    Mathematica Solve matrix differential system and asymptotic solution in mathematica

    hi i want to solve equation d/dt(A)=B which A and B are n by n matrices. the matrices variable is t which is time. 1-how i can solve this equation? 2-how i can obtain asymptotic solution for time=infinite? i use some help of this topic but i get error in mathematica...
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