0
votes
0answers
56 views

Display functions without dependence?

I'm solving systems of equations with a few different functions of time, t, and so I'm getting output with lots of [t] running around. Is there a way to display these functions without the ...
1
vote
0answers
27 views

Possible bug while plotting homographic function with stylled axes (?!) [duplicate]

Seems like a bug to me, don't have time to dig more now. WinXP V9.0.1.0 ...
1
vote
2answers
124 views

Computing lists using AstronomicalData

Edit: Initially in my question I asked how I could search the database of AstronomicalData["Exoplanets"] and return 2 filtered values that only contained valued ...
1
vote
1answer
344 views

Fourier Series of “Split” Defined Function

Not sure how to phrase this in a concise way, anyway it seems like the function FourierSeries assumes the interval for which to compute the Fourier coefficients of a given function is $[-\pi,\pi]$, ...
1
vote
1answer
186 views

Filling only part of a plot [duplicate]

I have something plotted on [-6,6] but I would like to fill only the part from [-5,5] (to the axis). I'm looking through the documentation but I'm not terribly well-versed in Mathematica and can't ...
3
votes
2answers
245 views

Draw only part of axis in graph

I'm looking to draw only one half of an axis in ContourPlot3D, mainly because I don't wan't the axis lines to be where the interesting stuff happens (intersection ...
4
votes
2answers
193 views

Graphing convolutions of user defined functions

I am a statistician who is very new to Mathematica. Ultimately I would like to be able to graph convolutions of arbitrary user defined functions. But I can't as yet obtain values of such ...
10
votes
3answers
1k views

help to plot Poincare section for double pendulum

I am reading a book about classical mechanics. In the chapter about chaos, it gives the simplified and scaled equations for double pendulum as $$ \frac{d}{dt}\left[ \begin{matrix} \alpha \\[3mm] ...
0
votes
2answers
603 views

Defining a function in terms of matrix elements

Currently trying to use elements from a matrix in defining a function however having some trouble. This is a somewhat simplified version of the problem. Say I have the matrix ...
4
votes
2answers
218 views

Can I frame text in a plot to look like legend?

I have a DateListPlot, much the same as below, that I want to overlay text onto. I'd like the text to be wrapped in a frame much the same way as the legend box is, ...
3
votes
1answer
65 views

Replacing multiple instances of a symbol with different variables and assignments

I have an expression of the form: expr=x+y+n+Sin[n]+n^2 I would like to replace each of the variables n with a different ...
0
votes
0answers
161 views

Differential equation with random variable

How can I derive analytically or compute numerically the solution to following differential equation $$ dy/dt = y\cdot X\cdot (y\cdot X - g(y,X))\cdot X $$ where X is a random variable (e.g. from a ...
0
votes
2answers
164 views

Associate the elements of a table

I have a table form as: table = {{a, 6}, {b, ff}, {c, 2}} I want to associate the first element of each pair from the table to the second element of the pair as ...
1
vote
0answers
69 views

Extract information from functions that returns nested structures with DefineDLLFunction

Where can I find examples devoted to extracting information from functions that returns nested structures with DefineDLLFunction in Mathematica? The only example I found and understood, was given by ...
2
votes
0answers
137 views

Calling Mathematica from Lazarus/Freepascal

I will appreciate if anyone can give me an hint about freepascal and mathematica mathlink communication. I'd like to build a Form using Lazarus/freepascal that call mathkernel. I'm trying to move ...
3
votes
1answer
90 views

some confusion about ReplaceRepeated

This is Right. NestWhile[Log, 100, # > 1 &] {100} //. {x_} /; x > 1 :> {Log[x]} 100. //. x_ /; x > 1 :> Log[x] This is wrong,why? ...
0
votes
1answer
44 views

Showing result of derivative and other functions [closed]

I have a problem with my Mathematica 7.0 When I write: Derivative[x^2, x] Mathematica returns as result : ...
15
votes
2answers
881 views

Why do certain values in ArcSin not fully evaluate?

This is a continuation of: Why do certain fractional values in TriangleWave not evaluate? The analysis by R.M and rasher revealed that problem to reduce to the behavior of: ...
4
votes
1answer
101 views

Issues with $MachineEpsilon

I'm attempting to add $MachineEpsilon to numbers I am pulling from the domains of 3 interpolating functions. I pulled 3 numbers, and for one of these numbers adding ...
1
vote
1answer
57 views

storing rescaled images in new variables

I'm trying to assign random image files that undergo rescaling to a list of variable names. The images I'm trying to assign are the result of mapping the ImageResize function of two arguments to the ...
4
votes
1answer
91 views

Why do certain fractional values in TriangleWave not evaluate?

While answering another question I discovered that TriangleWave does not automatically evaluate when given certain fractional values, specifically fractions with a ...
9
votes
2answers
263 views

How to avoid an expensive subset of a Manipulate computation when dependent variables have not changed?

I have a Manipulate where a portion of the calculation that ends up displayed is dependent on a subset of the Manipulate control ...
1
vote
2answers
108 views

ListPlot : range from $0$

I want to plot values of a table for example: table = {0.456, 0.7899, 1.3456, 9.8908} But I want to Plot points (x,y) like: ...
0
votes
0answers
21 views

Incorporating Built-In Function Options/Parameters into Shorthand [duplicate]

Shorthand syntax provides an alternate way to apply functions and, in many cases, improves readability. A simple example would be ...
2
votes
0answers
80 views

Limit[Sum[(2*E*n)^w/(w^(n/2+w)), {w,2,n}],n->Infinity]

I would like to show that the following (and other similar formulae) tends to zero. Limit[Sum[(2*E*n)^w/(w^(n/2+w)), {w,2,n}],n->Infinity] What's the right ...
-1
votes
1answer
120 views

Adding a textfield to the function that I implemented

Adding a textfield to the function that I implemented to represent the tangent or derivative of a function, but I've added so mark errors. ...
0
votes
0answers
28 views

Threading a single abscissa through a list of ordinates [duplicate]

Suppose that I have the following list, called list. list contains elements X, ...
1
vote
2answers
285 views

Expansion with binomial coefficients

How can I get binomial coefficients in expansion of $(n x+i) (1+i x)^n+(n x-i) (1-i x)^n$, where $i=\sqrt{-1}$ and $n$ is an integer. I have no idea how to coax Mathematica to do something remotely ...
3
votes
2answers
277 views

How to make slider in/visible in Manipulate?

I need your help with making a slider invisible and visible in a Manipulate. Here is my code: ...
0
votes
1answer
53 views

Replacing character in position

I'm trying to use Mathematica to make some work on binary data, and I'm missing something. Consider the string "111". I want to flip the last bit to become ...
0
votes
1answer
27 views

Is it possible to modify the options for a particular cell from another cell? [duplicate]

I was wondering if I can toggle the "CellOpen" state from a cell (or bunch of cells) from another cell. i.e. I am imagining having a manipulate command along the lines of: ...
0
votes
2answers
204 views

NDSolve boundary query / Extracting values from solution

I have a function $O_{2}$ with boundary conditions $O_{2}(r_{o}) = p_{o} $ and $O_{2}(g) = O_{2}'(g) = 0$. I plot it using the solver code below; ...
0
votes
3answers
124 views

Partial products in prime steps [duplicate]

I am trying to find out partial products going up in prime steps for Euler's product formula $$\prod_{p} \frac{1}{1-p^{-s}}$$ Trying things like ...
1
vote
1answer
180 views

Is linear interpolation applicable here

From my understanding about Linear Interpolation especially of that of Newton's Divided Difference Polynomial, we could get the value of F(x) from the given set of ...
3
votes
2answers
134 views

Evaluate in Plot leads to function error

Please help - I'm really struggling to understand why this evaluates with errors. ...
0
votes
1answer
61 views

Extend a function defined for integers to a differentiable function of a real variable

Here is a function that calculates the probability of randomly landing on a Fibonacci number not greater than $n$: ...
2
votes
4answers
295 views

How to set magnification of image to 75%

Right click on an output image, choose magnification. There are 25%, 50%, 100% etc. But how can I set to 75%?
1
vote
2answers
215 views

Find the centre of FindGeometricTransform

I'm interested in using Solve[] to find the centre point of rotation (as an $x,y,z$ coordinate point) and axis of rotation (as a vector) from a ...
1
vote
1answer
361 views

Fitting data using a differential equation

I have data generated from two functions given below. How can I go about finding a fit of the form: y'[x] == -(a + b/(c + d y[x] + e F[x] )) where a,b,c,d,e are ...
0
votes
1answer
61 views

Mapping a function of two arguments where the 2nd arg has a fixed value

I create three random images: i1 = Image[RandomReal[1, {8, 12, 3}]]; i2 = Image[RandomReal[1, {8, 12, 3}]]; i3 = Image[RandomReal[1, {8, 12, 3}]]; I can scale a ...
6
votes
1answer
167 views

How can I define a ⊕ operator?

What is wrong with the following code? CirclePlus := SparseArray[Band[{1, 1}] -> {##}] & a_ ⊕ b_ := CirclePlus[a, b] SetDelayed::write: Tag Function in ...
0
votes
1answer
75 views

Solving polynomial equations takes infinit time

I need to solve an polynimial equation, but when i try to use Solve or NSolve in mathematica, its cant find the solution in appropriate time (i interrupted calculation after 5 hour left). The ...
0
votes
3answers
179 views

Solving algebraic equations

How may I make n and k in terms of x and y in this ...
0
votes
0answers
15 views

Evaluating a String that is a Variable [duplicate]

I have a Variable assigned a value, say ImportantDocuments=1 How do I make N["ImportantDocuments"] evaluate to be 1 instead of ImportantDocuments I found that ...
4
votes
1answer
185 views

Passing Mathematica function via MathLink or LibraryLink to c (or c++)

I want to numerically solve the heat equation. To do so I wrote a program in C++ - It is a BVP $(\alpha T +\kappa \frac{\partial T}{\partial r}=f(t))$, where $f(t)$ is an arbitrary function, whose ...
0
votes
1answer
151 views

Why isn't Simplify completely simplifying my expression when it has all the necessary info?

I have a complex variable, and I'm trying to multiply it by its Conjugate[], which should give me a real number. So, I'm currently doing: ...
1
vote
3answers
199 views

Swap first and last names in a list

Edited to fix an inconsistency in the given example data format. I'm trying to write a simple function to load in a csv list of names which is formatted as "Lastname Firstname Initial " and ...
0
votes
1answer
171 views

PixelValue with pixel indices [duplicate]

How Can we use PixelValue with pixel indices?
20
votes
3answers
407 views

Why x = x doesn't cause an infinite loop, but f[x_] := f[x] does?

If I execute: In[1] := x = x Out[1] = x and then I evaluate the symbol x: ...
1
vote
2answers
259 views

Conditional range in a parametric plot

I have a program that needs to be done like this: ParametricPlot[ equation, If[x < 1, {x, 0, t}, {x, t, 2}]] But Mathematica didn't seem to recognize the ...

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