0
votes
0answers
2 views

NMinimize ignores constraints

I have a problem with NMinimize - I try to minimize quite a complicated function and use a couple of constraints (the way it is shown in the documentation). Now, the minimization happens quickly and ...
1
vote
2answers
36 views

How to create a function like in Python

Hi I am a newbee in Computer Programming (one semester of Java and Python in Univ) and especially in Mathematica. So please forgive me if I am being so illiterate. Basically what I want to do is the ...
0
votes
0answers
42 views

Analytical solution for bound state energies of infinite well [on hold]

I am trying to find bound state energies assuming infinite potential. I have been told it can be done by analytically solving Right Hand Side and Left Hand Side of an equation such as: $E^{1/2} ...
1
vote
0answers
30 views

Simultaneous fitting to multiple data sets with multiple variables and some common parameters

I am trying to fit two data sets to a function model described below which share a few common parameters. Say I have two functions with some common parameter(s) ...
0
votes
1answer
38 views

How to find all roots of a complex number

Finding all roots, and I know there are four f them, of this (1 - i)^(1/4)
2
votes
2answers
103 views

Mathematica data structures for analysis [on hold]

I'm starting to learn Mathematica and one thing that has been bugging me is the apparent lack of a good structure for keeping data and metadata for analysis. Something along R's ...
1
vote
0answers
37 views

Is there a summation notation for the sum of products made two by two? [migrated]

I have the following expression: $$x_1x_2+x_1x_3+\dots+x_1x_n+x_2x_3+x_2x_4+x_2x_5+\dots+x_2x_n+\dots+x_{n-1}x_n$$
0
votes
0answers
47 views

Why does my code produce NDSolveValue::ndnum?

I keep getting the error shown below. It appears to be valid, but I am not sure why my I am getting it. ...
0
votes
0answers
21 views

using numerical value of NDSolve solution

I have two differential equations solved using NDSolve ...
0
votes
0answers
22 views

Minimization of a non-linear objective function subject to linear constraints

I have solved a linear program in Mathematica using the LinearProgramming function with arguments of the form LinearProgramming[c,m,{{b1,s1},{b2,s2},...}] i.e. ...
0
votes
1answer
62 views

Mathematica 8 remove black background from image

How do I do that in Mathemtaica 8? I have found on this site many options like RemoveBackground[], but they don't work in Math.8. Are there any options? Here is ...
3
votes
2answers
54 views

Why doesn't FullSimplify simplify expressions with DiracDelta?

I want to simplify a complicated expression with some Dirac delta distributions, but FullSimplify does not do what I want. Specifically, I want ...
3
votes
2answers
76 views

Manipulate showing the trajectory of a particle

I'm trying to plot the trajectory of a particle: ...
6
votes
1answer
65 views

How do I format the output to include the function definition?

To explain, I do most of my probability homework in Mathematica, and use the typesetting built into Mathematica to finish answers. Often, I want to output a function as the answer to a problem, but I ...
5
votes
2answers
168 views

How to generate a chirped signal

As there is no ChirpSignal function in Mathematica, can anyone tell me how to write a custom function to generate a sinusoid with a frequency that changes ...
1
vote
1answer
32 views

How to take derivative of a tensor leading to kronecker delta? [duplicate]

I'm trying to write a Mathematica program to find derivatives such as the following simple example: Could you please help?
5
votes
1answer
166 views

Why doesn't this pattern work?

I want the in-built function Count to count the elements in a list which are greater than a value. Example: Count[{1, 1, 2, 3}, (# > 1.5) &] Why doesn't ...
1
vote
3answers
41 views

`Solve` with variables as single vector

Say I have a set of equations where the unknown variables are the elements of a vector $c=(c_1,c_2,\ldots)$ and want to solve it for $c$. Is there a way to do this with ...
1
vote
1answer
51 views

Compile with modification of arguments' values

Is it possible to compile while changing the value of the arguments the function receives, instead of just creating new variables, and then returning those new variables,i.e., is it possible to pass ...
8
votes
0answers
50 views

Bug(?) in version 10: Tooltip and ListPointPlot3D

Bug introduced in 10.0.0 The coordinates of a point in a three dimensional graph can be shown in a tooltip: ...
1
vote
0answers
41 views

How to use a C compiler without having SystemModeler

In this question the answer given implies that I must compile a certain function. When I try to compile I get the error A C compiler cannot be found on your system. Please consult the ...
3
votes
2answers
71 views

Find all roots in range

Is there any way to check for all roots in a range? Jens' findAllRoots function is pretty good, but runs at approx. 10% of roots missed when I ran a quick check on ...
4
votes
2answers
328 views

Colorize Grayscale Image

I have a grayscale image that contains two objects. The grayscale pixel values can be divided into three intervals where two of them represent objects and the third represents the background. The ...
1
vote
1answer
14 views

Unprotect fails the first time, works on second pass

I am redefining some of the standard math functions. I know this is dangerous, so I am trying to be extra careful. (For instance, in the redefinitions, I make sure to only match a custom head) The ...
4
votes
1answer
49 views

How can I use multiple Textures in Graphics3D

I am creating a Graphics3D object for a box using 6 Polygons (1 per side). I can use one single Texture on one or more sides but I can not find a way to use different Textures for different sides of ...
1
vote
2answers
34 views

Using conditionals to check if LinearSolve found a solution

Is there some way to check if LinearSolve found a solution using conditionals in Mathematica 9? I need to solve a large number of linear equations, but I am only interested in the cases where there ...
0
votes
0answers
43 views

ListContourPlot in V10

It seems that I obtain different results when using ListContourPlot under V9 and V10. Using this datafile http://pastebin.com/2p4ew0NJ (modified to use pastebin), ...
1
vote
1answer
35 views

Nothing happens when I click the mouse clicked on my graphics

I wrote codes to record list of coordinates when mouse clicked. It is expected that the coordinates should be plotted dynamically. But actually nothing happened. Can anybody help me to find the ...
0
votes
2answers
51 views

How do I get a Do function to create a list?

I have a Do function which gives me a column of expressions. How can I get the Do function to give me these expressions in a list. i.e The do function gives me this: a b c d I would like it do give ...
0
votes
1answer
56 views

Rotate points by 60° in 2D

I wrote this code, to rotate a list of points 60° about the first point in the list in 2D, but Mathemtica says: "Recursion depth of 1024 exceeded."
6
votes
1answer
90 views

Vertex displacement/merging in graph?

Given a Graph such as the one produced with the following code ...
2
votes
2answers
77 views

How to define multiple functions using a for command

Let's say I want to plot 10 graphs of those following functions. Since they are recursive functions, I cant make a table with 10 different initial conditions because Mathematica stores each value ...
2
votes
5answers
183 views

How to join two strings one of which is Subscript?

If I write this one str=Subscript["x","y"]; StringQ[str] False How can I get str as string?
1
vote
0answers
28 views

Plots to check all assumptions of linear regression

I'm running a linear regression with LinearModelFit and would like to plot graphs to check the assumptions of linear regression: linearity, independence of the ...
3
votes
0answers
43 views

How does Mathematica use system environment variables?

Is there a common way in which environment variables are accessed, stored, or used by the kernel? Some standard practice used by WRI programmers? There are built-in functions for querying and setting ...
0
votes
2answers
55 views

Open a .txt file in Mathematica [on hold]

i have a .txt file written for Mathematica, but wenn I open it with Mathematica, there is just an unreadable text and no graphs and simulations like it should actually be, could you tell me how to ...
3
votes
3answers
50 views

Tooltip with ListLinePlot and interpolation

Is it possible to get the coordinates of any point on a graph using Tooltip, ListLinePlot and interpolation ? For example on this simple example ...
7
votes
5answers
654 views

Check if two lists are equal in any order

Suppose I have two lists, how can I efficiently check if the two lists are identical up to permutations of the elements? For example I would like the function to output: ...
1
vote
2answers
62 views

Change Temporary Directory

How to change the value of $TemporaryDirectory ? I need to change it because there is not enough space on the C drive and the calculation seems to stop after a while !
-4
votes
0answers
50 views

Need help with GRE study question [on hold]

I encountered a question while preparing for GRE and am stuck. In an examination paper of 5 Questions, 5 percent of the candidates answered all of them and 5 percent none. Of the rest, 25 percent ...
3
votes
2answers
89 views

Equation of a transformed ellipsoid [on hold]

How do I use RotationTransform to transform the ellipse with respect to the y-axis? The origin of the ellipse has to be at a length of ...
2
votes
2answers
102 views

Matching a case when one element in a pair is Null

I've got a dataset of laitutdes and longitudes. Unfortunately, some of the dataset was from when a time when lat/longs weren't constantly recorded. So I need to remove the invalid data before working ...
0
votes
2answers
63 views

Problem in downloading “ToMatLab” package [duplicate]

Iam trying to download "ToMatLab" Package from http://library.wolfram.com/infocenter/MathSource/577/ but it is showing me an error message by showing a big question mark and "File could not be ...
0
votes
2answers
42 views

Restrict plot of object to be below a given plane in a ContourPlot3D

In a ContourPlot3D, I only want to part of the plot. Such as the part of a cylinder that lies beneath a plane. ...
6
votes
0answers
57 views

ParametricPlot MeshStyle bug in v10?

The documentation gives the following code and says "Use a red mesh in the x direction and a blue mesh in the y direction:" ...
4
votes
1answer
50 views

Problem with Neumann condition in quarter disc

So I'm following the available examples in version 10 for FEM, The plane stress operator is shown as this ...
0
votes
0answers
45 views

Calculating Value-At-Risk (VaR) in Mathematica. A simple code [on hold]

Calculating Value-At-Risk in Mathematica Obtaining data (Microsoft. Daily returns 2014): msftreturn = FinancialData["MSFT", "Return", "2014"][[All, 2]]; Code: ...
0
votes
1answer
63 views

Functions in functions

I have three functions f(x,y) , g(t) , and h(t) and somehow I have to find (d/dt)f(g(t),h(t)) where t = 0. How would I go about writing this in Mathematica? In this equation g(t) is taking place of x ...
2
votes
2answers
110 views

Solving 4 variable system of equations

Trying to solve a systems of equations. Here's the code: ...
2
votes
1answer
48 views

Problem with Style in a Plot

I would like to simply plot a density function $f_1$ and I would like to put a legend but I cannot do it as I wish. The problem is simple but I spent alot of time and couldnt solve it. I will be happy ...

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