# All Questions

66 views

### Pseudorandom selection with double constraints

I have an excel file with data in the format below and I want to extract 30 entries pseudorandomly. There are two constraints: Constraint 1: I need to select 30 of these rows with UPPER LIMITS on ...
176 views

### Why is my ListPlot rounding up fractions?

I'm trying to create a ListPlot that compares a country's poverty fraction with its cellular phone fraction. I'm using this to create the table. ...
105 views

### Why this code gives different output for differents runs

Edit Here is my code to plot many constrained variables in (x,y) plan : the variables are : ...
522 views

### How to debug the C code for LibraryLink?

Recently, I use the C to rewrite a Mathematica function NonzeroBasis[], please see here for fully descriptions. Here, ...
34 views

### NDSolve is not giving any result nor any error [on hold]

I am trying to solve a differential equation for $\psi$, but NDSolve is not giving any result nor any error. Please help me. My function is ...
33 views

### plotting a two variable real valued function with domain given in vector format or discrete

I have a function $g(x,y)= -2x+5y$ and vector $a=\{0,2,6,8,18,20,24,26\}$. I want to plot a $g(1,a)$ but i don't know how to plot it? I use following commands: ...
73 views

### How can I plot a function defined as a derivative of another function?

How can I plot a function defined as a derivative of another function? For example, y[x_] := Sin[x] y1[x_] := D[y[x], x] Plot[y1[x], {x, 0, 2 Pi}] doesn't ...
48 views

### How to prevent updating of an assignment

I have the code you see below: For[ni = 1, ni < 3, ni++, ALLB[[ni, 1]] = LB[[1, 1]];]; This code is written in a main notebook, and I have another sub ...
133 views

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31 views

### Arrange of several files

I am struggling to import my data. There are 400 files in CSV format with names organised by date like: Table1_20111003_YYYY_MM_DD_0000.dat. In each file over 20 colums and 86400 rows (seconds of ...
88 views

### How to get this terrible summation/product to run in Mathematica?

I've come across this formula and have no idea where to even start. (My assumption here is that $m,n$ are known and input into the expression to arrive at an answer.) f(m,n) = \sum_{\substack{0 \...
146 views

### Simultaneous plotting

For my experiment, I have to simultaneously fit the real part and imaginary part of cavity reflection data which is given here column 1: frequency, column 2: reflection magnitude, column 3: phase I ...
16 views

### web-embedded cdf plug in Raspberry pi3

web-embedded cdf plug in Raspberry pi3 hello. i am using rapsberry pi 3 and raspbian os. and mathemaica free on raspberry pi. but In raspberry pi web browser can not open(plug in) web-embedded cdf ...
185 views

### Random walk on a Sierpinski gasket

I am trying to simulate a random walk on a Sierpinski gasket. The best strategy i could come up with is to use Nearest point function to determine the next possible step of my walker. But this creates ...
88 views

### How does a construct like i : func[arg_] := i = an expression using arg work?

Occasionally I run into a Pattern that looks like i:func[arg_]:=i= an expression using arg I have two questions on this: Can ...
199 views

### How to perform convolutions on this complicated pdf?

I am working on problems related to the pdf q[y] where $y=Log[f]$ and f[x] is itself a pdf in x. But I can't figure out how to ...
53 views

### How to get smoother curves when plotting with mathematica 8.0?

Using the following line of code, I am trying to plot a few curves side-by-side. However, it turns out that the output curves are not that smooth as seen from the ups and downs (oscillating pattern) ...
52 views

### Plotting a set of parameters

I am trying to plot the equations that describe the Cartesian locations of Bi-Cylinder coordinates. The equations are as follows: ...
54 views

### How to implement search patterns and take into account language statistics?

Patterns in Mathematica I struggle some with patterns while trying to extract words out of large texts. Let us say that I have a long text (Strindberg) that we can call ...
94 views

### Background removal of gradient background

I am trying to calculate the sum of intensities present in my agarose gel: I want to compare the intensity of the total white band on the top with that of the one on the bottom. The idea is to ...
56 views

### DateListPlot from DateHistogram

How do I draw a DateListPlot from the bin height and bin middle position? I have a series of time events from which I calculate DateHistogram, but I want to represent the result through a kind ...
62 views

### Problems with Subsuperscript and Subscript Combination

I have a 3D figure, not important what it is, and I have the following code for the Z axis of this figure: ...
22 views

### FormBox in pretty strings

My goal is to write usage messages in the same style as Mathematica's built-in ones, such as List::usage. This involves a mess of ...
144 views

### Displaying Dandelin spheres touching hyperbola boundary patches in cone

Can we show the Dandelin spheres scenario (shown by Hrhm for case of ellipse) for a hyperbola as well? I'm not happy with what we get to see of this on the net. The double nappe/sheet of a cone is ...
81 views

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30 views

### Produce a function of parameters from a solution to parametric equation [on hold]

I am trying to produce a very simple result, namely given some function $f(x,a)=0$ find a solution $x(a)$ and let it be a function that I later plot depending on $a$. However Mathematica does not ...
81 views

### NDSolve how to monitor shooting method iteration?

here is a shooting method solution right out of the docs: ...
67 views

### Stiffness problem in an NDSolve system. StiffnessSwitching does not help?

I'm trying to solve an ODE system with the NDSolve method. This my ODE system, with the BC and the functions V and dV defined: ...
201 views

### Transforming a list of the form {{{x, y}, z}, … } into the form {{x, y, z}, … } [duplicate]

This should be a fairly simple question, but I can't figure out how to do it. I have a list of points of the following form: ...
59 views

### APIFunction calling another API

I've built a set of Wolfram APIs that call another API which builds specific queries given the parameters of a database and then outputs that query for the client in the query language syntax. Using <...
3k views
+50

### How can Mathematica be used to create images like these?

Here are two examples of artistic image interpolation using just black lines: TRIANGULATION: ANGULAR CELEBRITIES DRAWN WITH A PEN Interpolation for Triangulation-represented Digital Image The ...
70 views

### How-to derive conical region in an arbitrary geometry?

Description I have been working with derived geometric regions and ran into a problem when deriving RegionIntersection of a Cone...
51 views

### Saving the result of a NDSolve

I have solved this diff equation (with no problems): ...
55 views

### Problem using Nintegrate and NDsolve

I am going to use Nintegrate to integrate the result of NDsolve and also a Table. How I can ...
31 views

### The problem encounterend while calling a sub notebook from the main notebook

I have two notebooks; one of them is the main notebook which will call the second notebook several times in a loop and inside this loop, matrix called as ALLB, defined in the main notebook, will get ...
44 views

### ListPlot function in 2D- plan in two varibles

Suppose a function f[s,k]. How to Listplot this function in 2D plot in (s,k) plan, such that ...
6 views

### About calulus of variable [closed]

What are some good web link or pdf link to understand(self study) calculus of variable intuitively?I am a 12 th grade student with some notions of maxima and minima and some other notions in one ...
91 views

### Animating ballistic movement

I was tasked with creating a 3D animation of the movement of a ball through space, while taking into account influences such as the magnus effect, air drag, and rotation. In order for this to happen a ...
54 views

### Not able to apply Scan in place of For loop [closed]

I have been advised to avoid procedural loops and use other functions like Scan,NestList, FoldList, NestWhileList, Inner and Outer. My worry is that if I have a need in which certain critical ...
105 views

### How to plot a vector field on a geographic map?

Suppose I want to VectorPlot on a geographic map a vector field defined on a Reference Ellipsoid. The field is given to the following function as a ...
133 views

### How to extract the displayed name of an entity

Entities are typically displayed in their elided form: It's useful when exploring the output of EntityList to have access to the canonical name of the ...
67 views

### Evaluating Bessel-Schläfli-type Integral with Infinite contour

I am attempting to evaluate the integral $$\int_{\infty-i\pi}^{\infty+i\pi} dt \frac{e^{-\frac{l}{n}t}}{[(X'-X)^2+r^2+s^2- 2rs \cosh(t)]},$$ the only variable being $t$, ...
69 views

### Is the MMA formulation correct?

Let $H$ be a $4\times 8$ matrix and $R$ is a vector of 2 elements. ...
1k views

### Riffle but not quite

Given the two lists below, is there an in-built command or otherwise neat way of accomplishing the desired output. ...
78 views

### Softmax Regression Classification Algorithm

I'm following the Stanford Machine Learning course while simultaneously developing my Mathematica abilities. I'm having issues with my Softmax Classifier implementation (for ref, have a look at these ...
1k views

### My 3D plot of a Klein bottle doesn't look right

I have found the following parametrisation for a Klein bottle: ...