0
votes
1answer
28 views

Force ReplaceAll to output vector of same length

I would like to do a replace in an expression... a = t; b = 1; a/.t->Range[1,5] (*returns: {1,2,3,4,5} *) b/.t->Range[1,5] (*returns: 1 *) but I ...
4
votes
1answer
405 views

Something interesting about Pi, but something seems amiss

I saw something interesting about text-analysis - bigrams - in Basic Text Analysis in Mathematica I wondered how the bigrams of Pi's digits might appear. As expected, take enough terms and every ...
0
votes
0answers
38 views

Parametric Plot and Dynamic [closed]

I have: ...
1
vote
2answers
56 views

How change style of InputField in a Manipulate?

Is it possible to specify a style, e.g., font size, for InputField type controls inside a Manipulate and if so, how? For ...
0
votes
1answer
33 views

Calling a function on a variable with parameters [duplicate]

I have an equation that contains parameters. I want to use it in a function like NDSolve, but I can't seem to figure out how to do so. Here's an example: I define ...
1
vote
1answer
37 views

How to separate linear terms by output?

I am performing a complicated summation in which fa is a Sum of a[j] over j, and terms in fa end up containing a BesselJ, a Hypergeometric0F1, or neither. ...
3
votes
1answer
91 views

How can I overload a function with multiple bracket-slots so f[a][b] and f[a] can coexist?

Maybe this is not even possible: I want to create a function f that can have two input brackets like: f[a_][b_:1]:= a*b and ...
4
votes
1answer
155 views

How can I construct a recursive pattern guard?

I am modelling binary trees in Wolfram Language by writing them as three-element lists, like so: binTree = {nodeVal, leftChild, rightChild}. It does not yet matter ...
3
votes
1answer
82 views

How to label my training images?

I'm switching over Matlab, but I have a problem. Matlab has a GUI tool called the "Training Image Labeler" (shown below) that I use all the time to label my training data for my computer vision ...
0
votes
0answers
21 views

Integers of particular forms [migrated]

For positive integers x,let s(x) be the sum of the digits of x,and let d(x) be the number of digits of x. Is there natural number of the form 10^(8+9n)+8+9n that cannot be written as x+s(x)-d(x) ? (I ...
3
votes
1answer
55 views

How can one debug a module more elegant than just with Print?

This question is interesting mainly for beginners, but the answer i wrote to my own question could be also interesting for advanced users. Introduction: While writing huge blocks of code, especially ...
0
votes
1answer
55 views

Can't get solution to a system of recurrence equeations

I would be grateful if someone could help me with this problem. I define two series recursively, thus: ...
1
vote
1answer
44 views

NestList and RandomChoice from a list of functions

I am tryingg to modify Chaos Game Fractals from Wolfram Demonstrations. The part I am having problem with is this. Original code: ...
5
votes
5answers
110 views

Isolating cross terms

I have a set of expressions that contains terms like $\frac{1}{(x + a + b)(c+d)}$. I would like to simplify the denominator so that products of $a,b,c,d$ are dropped, but $x c$ and $x d$ are kept. ...
0
votes
1answer
54 views

How to specify the domain of a variable?

How can I specify for every expression the domain of a variable without using assumptions everytime i have to simplify it?
1
vote
0answers
44 views

Evaluating documentation example crashes the kernel

Save your work before attempting: Could someone confirm what looks like a bug (definitely occurs in v10 and OSX 10.8.5): In the documentation for Background and ...
0
votes
0answers
44 views

Linearization of differential equation - need tips for the use of Series function

I would like to linearize a differential equation around a equilibrium position. The description of the steps that I have carried out are : Equation ...
0
votes
3answers
77 views

Why does FindMinimum return 'The function value Null is not a real number'?

I am working with the following function ...
0
votes
0answers
22 views

Fit a complicated function to a constant with NonlinearModelFit

I wish to fit a complicated parametric function (logder, with lambda parameters) to a constant (L) in order to minimize its dependence with the variable k in a given interval. To do that, I use a ...
0
votes
1answer
20 views

Using Coefficient to pick combinations of parameters in an expression

I have the expression $$ c \partial_{\chi} u = \mu u - \nu v - (u + \beta v)|A|^2 + (\partial_{\chi}^2 u - \alpha \partial_{\chi}^2 v) + \gamma u \\ c \partial_{\chi} v = \mu v + \nu u - (v - \beta ...
3
votes
2answers
68 views

Overlay vector logarithmic plot and rasterized logarithmic ListPlot

I would like to produce a output PDF file of a log-linear plot obtain by composing the plot of an analytical function and a scatter plot of some random data. Since the random points are of the order ...
6
votes
1answer
101 views

What really makes a Dialog expresion behave as a modal dialog?

CreateDialog[DefaultButton[], Modal -> True] creates a modal Dialog, one which needs to be closed before the front-end ...
1
vote
3answers
92 views

IntegerQ returning False despite setting Assumptions

Why does the following not return True? Assuming[z ∈ Integers, IntegerQ[z]] False I tried this on a fresh session of ...
6
votes
2answers
135 views

Color lines by angle

I would like to color some lines according to the following color function: ...
1
vote
1answer
33 views

Fitting data with a complex function, but requiring real parameters

I am trying to fit a complex data with a complex function, with the real fitting parameters. I was trying to put there constraints like this, but I got error: ...
1
vote
1answer
70 views

PDE solution does not satisfy Neumann boundary conditions using NDSolve

I am trying to solve the free particle Schrodinger equation in 1D (hbar =1, Energy = 1, mass = 1), But specifying conditions only on x==0: ...
-1
votes
1answer
41 views

Specify and rename ticks in FrameTicks

When I plot, I use Frame -> True I would like all ticks on the frame axes to disappear and remain only with two ticks, say, 0.1 on the x-axis and 0.5 on the y ...
3
votes
1answer
120 views

Series approximation to integral

I would like to approximate the integral $$ \int_0^\infty dy\,\frac{1}{\sqrt{2\pi y\sigma^2}}\exp\left(-\frac{(x-y)^2}{2y\sigma^2}\right)f(y), $$ as a series expansion in the limit $\sigma\rightarrow ...
0
votes
1answer
33 views

Integration with changing parameter [closed]

I want to calculate the integral of Rev for a = 0 to 1 by step 0.1. How can I do it? ...
0
votes
0answers
47 views

How could I solve following equation? [closed]

I am quiet new to Mathematica. I was wondering if someone could give me some pointers towards solving an equation of this sort: Here is what I know: The change of temperature, T (Celsius) with ...
0
votes
1answer
36 views

Complex number plot with inequalities [duplicate]

I need to plot the function where z is a complex number: $$S = {z:|z + 0.15|<0.6} \wedge {z:Pi/4<=arg(z)<=Pi}$$ I can do this: ...
-1
votes
1answer
69 views

Translate Maple code into Mathematica [closed]

I am trying to translate Maple code into Mathematica. Here is my code: Can anyone help me to obtain a translation? I especially want to know the Mathematica equivalent of Maple's ...
7
votes
1answer
200 views

Computing launch parameters for hitting a point in 3D with projectile under influence of wind

The end goal of this problem is to compute functions which describe the launch parameters which are needed to hit a specified goal in 3D in the presence of wind disturbances. This is as far I have ...
-2
votes
1answer
59 views

Transform differential equation to get equilibrium position

I would like to determine the equation in the equilibrium position. eq = 1/2 g l m Cos[θ[t]] == J (θ^′′)[t] ...
0
votes
0answers
48 views

How can I solve my problem in NIntegrate? [closed]

Can anyone help me solve my problem with NIntegrate? ...
0
votes
1answer
26 views

ReplaceAll::reps: error [closed]

...
0
votes
0answers
21 views

Solution of Laplace equation in Cylindrical Coordinates [closed]

can anyone help me solving laplace eqn in cylindrical coordinates. I want the solution by Separation method resulting in Bessel function. 1/r d^2(u[x,theta,z,t])/dr^2 + d(u[x,theta,z,t])/dr + 1/r^2 ...
7
votes
1answer
143 views

Ghost trails with Animate?

What are some approaches to integrate Ghost trails methods with Animate, which otherwise seem more suited for exporting individual frames? For example, given this rootPlot function, how can trails ...
0
votes
2answers
44 views

Parametric Plots [continuous and discrete]: --showing parameter increase for multiple values of another parameter

In my problem, I am effectively plotting a parametric function that depends also on an outside parameter, e.g., the real/imaginary parts of ...
6
votes
1answer
182 views

How can a function know in which function it was evaluated?

Hello my second question here might be very hard. I am asking for something "magical", if i define a function g and i call it inside a function f, how can g have information about the outer function ...
2
votes
2answers
56 views

Need help updating an old Mathematica worksheet

I found a notebook that symbolically applies the multiple time scales method to any differential equations. I don't like just using other people's code so I am going through the author's work line by ...
0
votes
2answers
41 views

Constructing a table from a constraint on another table

I have a 1000X6 table, where in each row the first three columns are dependent on the second three. I then make smaller tables of 1000X2 from these first three columns and basically ...
1
vote
2answers
89 views

A cone being intercepted by a slanted plane

I have the 3d cone: Plot3D[-Sqrt[x^2 + y^2], {x, -20, 20}, {y, -20, 20}, Mesh -> None, BoxRatios -> {1, 1, 1}] I need a slanted plane intersecting it. ...
0
votes
1answer
31 views

Problem with showing results in a Manipulate in a cdf-file

I have a problem with showing my results correctly in a Manipulate in a cdf-file. My program (for my bachelor thesis) can calculate the income law with a income entered into an input field; the use ...
0
votes
1answer
37 views

Region projection of multivariable interpolated function

I have a problem plotting a multivariable interpolated function when projected into two-dimensions using Resolve and RegionPlot. ...
0
votes
2answers
37 views

FilterRules with pattern for name [duplicate]

I have a list of rules and I want to filter it using a pattern for the initial string representing the name of the rule. So that in the example below it filters linearBool even if it is called ...
1
vote
1answer
49 views

Generate 2d image from image3d object

I have created a image3d from which I have rotated it to create a rotating view of the object. I want to be able to render each 'frame' to a 2d image so that I can export the frame sequence to create ...
1
vote
3answers
151 views

Defining functions when there are a lot of parameters

Suppose I have two lists of parameters: $\delta=\{\delta1, \delta2, …\}$ and $\gamma = \{\gamma1, \gamma2, …\}$. The question is: how can one use $\delta$ and $\gamma$ (the parameter vectors) within ...
0
votes
2answers
57 views

Why does Solve give a wrong solution to an equation? [closed]

I have got a following equation: -(c - x)/Sqrt[b^2 + (c - x)^2] + x/Sqrt[a^2 + x^2] == 0. Trying to solve it for x, so I evaluate ...
0
votes
0answers
31 views

“Enlarge” a plot for export

I wish to export a plot with more resolution than it starts with. Interactively, I can do this by enlarging the image, and then exporting. Is there a way to do this programmatically? I attempted to ...

15 30 50 per page