# All Questions

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 ...
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 ...
38 views

I have: ...
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 ...
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 ...
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. ...
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 ...
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 ...
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 ...
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 ...
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 ...
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: ...
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: ...
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. ...
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?
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 ...
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 ...
77 views

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

I am working with the following function ...
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 ...
20 views

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 ...
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 ...
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] ...
48 views

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

Can anyone help me solve my problem with NIntegrate? ...
26 views

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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 ...
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 ...
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 ...
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 ...
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 ...
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 ...
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. ...
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 ...
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. ...
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 ...
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 ...
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 ...