6
votes
2answers
129 views

Color lines by angle

I would like to color some lines according to the following color function: ...
1
vote
1answer
31 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
60 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
37 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
119 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 [on hold]

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? [on hold]

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
34 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
67 views

Translate Maple code into Mathematica [on hold]

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 ...
6
votes
1answer
167 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? [on hold]

Can anyone help me solve my problem with NIntegrate? ...
0
votes
1answer
25 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
129 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
42 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
179 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
55 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
38 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
36 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
36 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
48 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
149 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
56 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
30 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 ...
0
votes
1answer
53 views

Correcting image distortion by warping a set of distorted points to a corresponding set of undistorted points

I was hoping someone might be able to help me undistort an image in Mathematica. The distortion doesn't follow any specific pattern, but there are several points on the distorted image that I am able ...
1
vote
0answers
53 views

Calculate exact Probability of product of normal random variables

Find the value of $P[\Pi_{i=1}^{10}X_i > C]$ for $C=5$, where $X_{10\times 1}$ is a random vector with $10$ dimensional Normal Distribution having location parameter $\mu_{10\times 1} = ...
1
vote
0answers
35 views

ParametricNDSolveValue over a region

I'm getting the following behavior I don't understand when using ParametricNDSolveValue over a region. You can reproduce the behavior considering Poisson's equation ...
1
vote
1answer
46 views

Dynamically Update both a HorizontalGauge range and the value

I'm developing a demonstration that allows students to explore the location of a point on a number line simultaneously at various scales. I'll show a very simplified version here to get to the nub of ...
-2
votes
0answers
37 views

Specifying temporal precision in DateRange

DateRange inserts undesirable precision: ...
0
votes
1answer
60 views

How to plot 3D maximum and minimum surfaces? [closed]

I want to plot the maximum and minimum 3D surface for the following property: ...
2
votes
0answers
50 views

How can I apply NotebookGet on invisible Notebooks?

My problem might be very specific, but can be quickly explained: First I create an invisible notebook nb by CreateDocument, then i apply NotebookGet on it to see its content, wich works fine! Now I ...
0
votes
0answers
33 views

Solve system of equations derived with the Lagrange approach

I am new here and hopefully you can answer my question. I have to pictures attached. The problem is as follows. I have 4 system equations, derived with the Lagrangian approach. Now I want to ...
0
votes
2answers
30 views

Simulate from an AR(1) process where the parameters vary over time

I would like to simulate from an AR(1) process, where the $\rho$ parameter in the process of the form: $X_t = \rho X_{t-1} + \epsilon_t$ varies over time. The path of $\rho$ and $var(\epsilon_t)$ ...
1
vote
1answer
57 views

Is there an easy way to transform unit vectors from spherical to Cartesian coordinates? [duplicate]

Is there a built-in function on Mathematica that will transform unit vectors from one coordinate system to another? I have a vector expressed in spherical coordinates, and I would like to find the ...
1
vote
2answers
44 views

Differentiation of an unknown function

I have to take the partial differentiation of an unknown function. For example, take the unknown function to be $g(x)$. Then it's derivative w.r.t $x$ is $g'(x)$. By default, Mathematica ...
0
votes
0answers
28 views

NDSolve dependence on initial values

I'm checking some results in this paper and I'm currently having some issues with a numerical integration of a set of differential equations using NDSolve (section 2 and 3.1-3.2 in the paper). I'll ...
1
vote
2answers
56 views

how to remove Null's from output? [duplicate]

I'm a math enthusiast and I'm looking for examples of rare divisibilities, let's look at the following one: ...
0
votes
0answers
28 views

NDSolve — using a PDE solution in another PDE

My problem is to use the numerical solution of a PDE as a function appearing in another PDE. Here is the code solving the first PDE (heat equation in a domain) : ...
2
votes
2answers
51 views

RSolve with conditional equation

I have the following conditional equation: $f(n) = 1+2 f(n/2)$ when n is even $f(n) = 1+f((n-1)/2)+f((n+1)/2)$ when n is odd I want to represent this as a conditional equation to be used in ...
0
votes
0answers
31 views

MMA 10.0.2 Windows x64 Crashes during Find Next/Previous

For the past few weeks, MMA has crashed over a dozen times. It only happens when I'm doing Find Next or Find Previous several times while searching through my notebook. Note that I have at least 2 ...
0
votes
0answers
24 views

Multidimensional Fourier PDE solution and and exact solution are scaled by $(2 \pi)^{2}$

I'm solving a partial differential equation (Stokes equation) in a periodic domain in three dimensions with fourier transforms. I'm using Fourier[] mathematica routines to perform the discrete ...
0
votes
1answer
40 views

Permanently fixing a variable in the function

I need to define a function let's say f[x_, y_] := x^2 + y^2 such that I need to fix one variable (let's take y = a) and to ...
12
votes
3answers
911 views

Finding a function that fits the shape of an image

How can I find a function that fits the given shape of an image? Or instead extract a point set from the shape and then find an interpolating function fits the shape. An example image is attached.
2
votes
1answer
56 views

Patterns for destructuring “Function” function arguments

I want to define a function for finding a Jacobian matrix of pure vector function of vector argument. I try ...
0
votes
1answer
28 views

Resolving a logical statement

I would like to test whether f[n] > 0 and f[n + 1] > 0 implies f[n + 2] > 0. This ...
0
votes
0answers
30 views

Changing the style of the Error Bars

I'm trying to get to change the length of the line at the top and the bottom of the error bars, but I have no idea how to do it. Can anyone help? Thanks!
0
votes
0answers
25 views

Copy an image into a cell will auto generate an inline Cell

Copy/Cut an Image from a cell into another, will auto generate an inline cell. Sometimes I just want to copy/cut an image into a Text-Style Cell, the below image shows some possible results of this ...

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