Questions tagged [variable]
Questions on the use or manipulation of Mathematica variables (i.e. names associated with a changeable value). Use [variable-definitions] or [assignment] for questions on variable context localization, or assignment.
341
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4
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Is it possible for Mathematica to output the name of a matrix as opposed to its matrix form?
I am interested in working with the names of matrices as opposed to the actual matrices themselves. I would like Mathematica to recognise the content of a matrix and output its name rather than its ...
- 627
1
vote
0
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50
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Why does functional form of integration output depend on variables used?
The following integration code is identical, except for the use of integration variables x vs k and constants ...
- 980
1
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1
answer
65
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Import all files in NotebookDirectory, store each list in a variable with the file name without extension
I have many files stored in the notebook directory, which are called "lista.dat", "listb.dat", ... I would like to import all of them and save them as variables called "lista&...
- 23
1
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0
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37
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Integral within another integral [duplicate]
I have to evaluate the following integral:
$I(k) = \int^{42}_{0} dt \hspace{0.1cm} 3t^3*e^{i \int_{0}^{t}dx( x^2 - \sqrt{x^4+k^2/x}) }/\sqrt{t^4+k^2/t}$
The answer in : Iterated integral numerically
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0
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0
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27
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How to find the argument dependance of an expression
Consider expressions such as
X := f[n[1]][n[3]] g[n[7], n[1923]]
I would like to construct a function that returns the list of $n$'s on which $X$ depends. I know ...
- 375
1
vote
1
answer
70
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How can I solve this inequality? Can I provide extra information when doing Solve?
I am new to Mathematica so I could really use your help.
I am hoping to figure out the condition that the following function is larger than 0.
I tried to FullSimplify it and to simplify it myself ...
- 25
1
vote
0
answers
31
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NDSolve with matrix variables and SymplecticPartitionedRungeKutta [closed]
I'm experimenting with solution of differential equations with matrix variables, where the right hand side is defined as a numerically evaluated function of a matrix. Here is a simple example:
...
- 303
1
vote
1
answer
99
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Equation with 3 variables running forever [closed]
I am new to this and was trying to solve an equation. Yet, it is taking more than 6 hours, and I am unsure if I typed something wrong or if my laptop settings are incompatible with the software. Any ...
- 25
0
votes
1
answer
58
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Defining a function of a variable through another intermediate variable
The following is a really simplified version of what I'm trying to do. I have a variable fn defined in terms some other variable x. I then want to define a function of x through the variable fn.
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- 471
1
vote
1
answer
69
views
Find an instance satisfying equation
I have the following equation with two variables xi and nu.
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- 496
1
vote
2
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How can Mathematica merge $(1/t)^{1/3} t^{17/3}$ in an expression?
(1/t)^(1/3) t^(17/3)
How to let Mathematica simplify it?
- 11
0
votes
0
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52
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Identify a condition among variables that satisfy an inequality
I have a symbolic function that produces the output
a = (1 - e - mu/n) Log[(1 - e - mu/n)/(1 - mu/n)] + (e + mu/n) Log[((e + mu/n) n)/mu]
If I substitute ...
- 496
0
votes
1
answer
67
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A specific usage of "Solve" function [duplicate]
It is something from Simplifying polynomials with conditions on variables, that intend to minimize the number of variables.
The problem is the usage of ``Solve". I know how to solve equations, ...
- 115
0
votes
0
answers
56
views
how to use subscripted variable such as a_i as the control of Manipulate?
I'd like to define a series of variables called $l_1$,$l_2$, etc., in Mathematica, using the "ctrl+_" shortcut. Moreover, I want to use these variables as the controls of a Manipulate[] ...
- 735
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1
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133
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How can I define a function with a variable with subscript?
I want to define a function in Mathematica:
$$h(\tau_x)=\tau_x$$
$\tau_x$ has no special meaning. To be honest, it's totally OK if I use the function $h(x)=x$ to replace $h(\tau_x)=\tau_x$. It doesn't ...
- 113