2
votes
3answers
106 views

Permutations and recurrence equation

First problem: I need to show all Permutations with length 4 of this elements {x, y, z, w, t} but with this condition: the element z mustn't be after element t. I ...
0
votes
1answer
98 views

Applying ReplaceAll to I (imaginary unit) [closed]

Why does I/.I->-I return -I but Exp[-I]/.I->-I yields ...
0
votes
1answer
67 views

Question about the third argument of Solve [duplicate]

I'm learning about derivatives. This is my code: ...
1
vote
0answers
152 views

How do I fit the parameters describing a 3D object so that it best resembles its projection seen by an observer at a particular position?

I have data which are the longitudes (l) and latitudes (b) for the vertices of the edges of a shape as it appears to an observer at a given location (i.e., as it appears on the observer's sky plane). ...
0
votes
0answers
41 views

InverseFourier of nested lists

last week I've got an Mathematica package that is using several inverse Fourier transforms on a data cube ($n\times n\times n$-array). I'm implementing the same functionality in C++ and tried to ...
1
vote
3answers
237 views

How can I use functions in file paths?

I'm very new to Mathematica and I'm trying to write into a file. I want to have a function in my file path. For Example: ...
2
votes
2answers
201 views

Study the possible coincidences of the three clock hands hour, minute, and second

Inspired by the very nice problem solutions of the problem of coinciding clock hands, I'd like to extend the question including a "second" hand. While it is obvious that all three hand can coincide ...
0
votes
2answers
128 views

Continuity of function-example

I'd like to examine the continuity of the following function: f[x_] := Limit[(n^x - n^(-x) ) / (n^x + n^(-x) ), n -> Infinity] I know that this function isn't ...
1
vote
2answers
60 views

How to generate commands which are very similar?

I have several data sets that I wish to interpolate and integrate like this: ...
4
votes
1answer
116 views

Kernel crash when using NIntegrate with Throw/Catch

Bug fixed in 10.2.0 My code is: ...
1
vote
1answer
58 views

series combinations

is there any possibility of displaying all possible series of the form: "1+/-2^2+/-3^2+/-...+/-n^2", where one can choose the sign before the each term and knows the numbers of the terms in the ...
0
votes
1answer
283 views

How to do multiple integral numerically?

I cannot calculate the following type of integrals numerically : $\int_0^1 dy \int_0^y f(x) dx $ $f(x)$ can be a complicated function. The problem is due to the fact that the upper limit of one of ...
3
votes
2answers
374 views

How to solve numerically an equation which contains numerical intergration?

F1[x_] := NIntegrate[E^Sin[y x], {y, 0, 1}] F2[x_] := Log[x] NSolve[F1[x] == F2[x], x] I want to solve the equation, but Mathematica don't solve it. ...
2
votes
2answers
175 views

Approximation of definite integral by parabolas

This question is related to Trapezoid approximation to definite integral. As promised, I am now asking about how to draw approximation of integrals by parabolas. I tried to modify MarcoB's code, and I ...
3
votes
1answer
146 views

Can I make a simple game in Mathematica?

Here is the game outline: $\hspace{2.5cm}$ There is one player. The player ($\mathscr{L}$) moves from node to node limited by the directed arrows. As the player moves, $\mathscr{G}_{\Huge\cdot}$ ...
0
votes
2answers
83 views

Manipulating a damped oscillator plot - plot does not show

I was trying to make an oscillation plot that could be manipulated depending on the value of $\beta$. The differential equation is below, and when I just plot the solution, it turns out to be the ...
25
votes
0answers
560 views

Performance problems in new Sequence functions

The new-in-10.1 Sequence* family of functions should provide newly optimized methods for handling sequence problems. Happily in some cases they do! For example ...
1
vote
1answer
109 views

Work around bugs in Summation, Hypergeometric function?

I'm so confused I don't even know how to phrase the question, so here's what's happening: I need an analytic form for this: ...
1
vote
0answers
40 views

Using ForAll in Maximize to define a bunch of conditions [closed]

I'm trying to do something very straight forward. The following maximization works: ...
6
votes
2answers
196 views

Subsets or Outer?

How do I generate all possible subsets of a list of positive numbers (with at least 1 of them), given that each of these positive numbers subvariates itself on its input value and its multiplicative ...
2
votes
1answer
53 views

Transform an XMLObject with XMLElements with empty attributes

I would like to transform a an XMLObject so as to replace all the non empty attributes of the XMLElements by empty attributes. ...
1
vote
1answer
395 views

Solving a complex logarithmic equation

I am trying to solve the following equation for $x$, with integer $n$. (1 - ((-1 + x)^E x^(1 - x) Log[x]^-E)^(1/(-1 + E)))/(-1 + x) == n
-2
votes
1answer
65 views

Doing calculation on an imported data file [closed]

I have a data file which has been calculated from mathematica code and saved in test.txt, I need to import the data and do new calculation on it, here is the simple ...
6
votes
0answers
248 views

Is there a way to update Workbench 2.0 to recognize Mathematica 9, 10 and 10.1 functions?

Is there a way to add newer functions to a configuration file so that Workbench 2.0 is useable for development with 10.1? Also, are there changes that can be made so that Workbench 2.0 can be used to ...
3
votes
0answers
124 views

Different FourierParameters in each dimension for discrete Fourier transform

I have a query about the Fourier utility, that does discrete Fourier transforms. I am unable to find any information on whether different FourierParameters can be used in each dimension. This is a ...
-2
votes
1answer
143 views
9
votes
0answers
163 views

Make the map of rivers and lakes of the country

As I understand,first of all I should to get the country's map and the river's list. To get country map is simple: ...
-1
votes
2answers
190 views

How to change the plot range of on an axis other than z in a ListPlot3D [closed]

ListPlot3D[Table[Tan[j i], {i, 0, Pi, 0.1}, {j, 0, Pi, 0.1}]] I want to choose the plot range of y or x-axis so that for example only the right "hill" of the ...
2
votes
3answers
427 views

Converting timestamps into a decimal in minutes

I am importing a list of timestamps (hour:minutes:seconds) from a series of text files. I have the list: ...
8
votes
1answer
225 views

Curious solutions of x' = Sqrt(x), x(0)=4

Consider the solution of $x'=\sqrt{x}$, $x(0)=4$ using DSolve. ...
2
votes
3answers
192 views

How to rotate a complete graph without image rescaling while rotating

How do I rotate the following image? ...
3
votes
1answer
61 views

Splitting formatted output to multiple lines in a controlled fashion

Let's consider a slightly complicated expression in TraditionalForm: ...
0
votes
0answers
33 views

Why is DownValues releasing RuleDelayed's hold for Graphics? [duplicate]

I am trying to understand DownValues in regards to the evaluation of its output. Consider this: ...
2
votes
1answer
68 views

How to NDSolve a set of equations, one of which itself contains NIntegrate of a desired function?

How to NDSolve a set of equations, one of which itself contains NIntegrate of a desired function waited to be solved by NDSolve first? For example, ...
6
votes
1answer
86 views

How to simplify expressions by closing open inequalities?

Recently I have often acquired results which consist of combinations of 0, 1 and 2-dimensional (in)equalities. For instance, consider a very simple case with ineq1 ...
0
votes
1answer
64 views

Compute and Plot the element of a complex sequence

I'm new tho mathematica. I have a complex sequence ${z_n}$ with $z_0:=c$ $z_{n+1}=(z_n)^2+c$ for all $n\in N$ where c is some complex number, I need to plot the first 20 terms of this sequence ...
1
vote
1answer
76 views

NMinimize error: Nearest::neard:

I have this function GuessError, here's a plot assuming a single variable x, Plot[GuessError[10^x, etc..], {x, 8, 12}] , being etc some more variables which are ...
1
vote
2answers
50 views

Want apply “Position” in my list of Entities

I want apply "Position" in my list of Entities: Entity /@ GeoEntities[CountryData["Belarus"], "Lake" | "Canal"]["Position"] ...
1
vote
1answer
75 views

TSV import issue

I am having an issue importing a tab-seperated file properly. Most lines get split into elements based on the tabs but some don't: ...
2
votes
1answer
77 views

how to manipulate indices in a table/vector

Perhaps I'm missing something very basic. Could somebody guide me how to manipulate indices of a list. For example, if I have ...
5
votes
1answer
111 views

Handy dates conversion

I feel like something very basic is missing me, $dateformat = {"Year", "Month", "Day", "Hour"}; date = DateString[$dateformat] DateString["Date"] ...
1
vote
1answer
147 views

GCD of Table entries

This question is from a newbie, so please be gentle in thrashing if I'm missing something very basic. How can I use GCD on a matrix/vector entries stored as Table. For example, if ...
0
votes
1answer
64 views

Problem with double sum on the calculation of Ricci tensor

I wrote a program in Mathematica to calculate the Riemann and Ricci tensors (obviously, passing trought Christoffel symbols first), however just later I thought of calculating Ricci tensor directily ...
3
votes
1answer
128 views

Constructing lists in an efficient way

I have a list of functions and I want to separate them into two lists: a list that contains the functions that have at least one zero and a list that contains the functions that do not have ...
4
votes
2answers
52 views

NaNs in tabular data and import performance

I'm working with some data files that are just too large for Import. I tried using ReadList, specifying either ...
0
votes
0answers
25 views

Stopping resetting of linked locators in manipulate [duplicate]

I have found several solutions for linking locators (using the second argument for Dynamic) but they have the following problem: How do I keep the locators from resetting, when I choose something ...
1
vote
0answers
36 views

Edit Notebook options in version 10 [duplicate]

This is a follow up question to this one. I was closing a notebook without saving, Mathematica (10) showed me this dialogue: and I clicked "Save", when I re-opened the notebook I found this ...
3
votes
2answers
338 views

Count the number of regions made by Lissajous curve

How many disconnected regions does Lissajous curve divide the plane into? For example: Let g=ParametricPlot[{Sin[2 t], Sin[t]}, {t, 0, 2 \[Pi]}] The number ...
1
vote
0answers
123 views

How to import all the images in a folder? [closed]

the source code is ...
5
votes
1answer
96 views

Integrate gives Simplify::infd “simplified to Indeterminate” message

Using version 10.1 on windows 7 Integrate gives this Simplify::infd Kernel message. What causes it, is this a bug? ...

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