2
votes
1answer
108 views

Scaling of ChartElements

In attempting to answer this question from @Cam on BubbleCharts with elliptical bubbles, I suggested using separate ...
0
votes
1answer
72 views

Is there a more idiomatic way to solve this implicit differentiation problem?

Here's an exercise from a calculus text by Larson and Edwards: Find the rate of change of the distance between the origin and a moving point on the graph of $y = x^2 + 1$ if $dx/dt = 2$ ...
15
votes
3answers
519 views

Comparing Mathematica expressions like diff

I am looking for a way to compare (or "diff") two Mathematica expressions, similarly to how to diff utility can compare two text files and report the differences. Has anyone already written such a ...
2
votes
0answers
308 views

Adapting NDSolve to circumvent NDSolve::bdord: error for 1-D Euler Equations

I attempted to use NDSolve for the 1-D isentropic unsteady flow equations with low subsonic inflow velocity and prescribed inflow total enthalpy; along with a ...
4
votes
2answers
354 views

Override Equation structure change in mathematica - CopyToLaTeX

I am writing my thesis, and when I do copy to LaTeX from Mathematica, it changes the equation variables and also it rearranges the structure of the original equation. How can I override that ?? ...
0
votes
1answer
1k views

Plotting two surfaces and visualizing their intersection

Trying to plot the following two functions to show points of intersection. ...
0
votes
2answers
1k views

How to manipulate plot range with fixed axes

I want to achieve something like this Manipulate[Plot[Sin[x], {x, 0, r}, PlotRange -> {{0, 10}, {-1, 1}}], {r, 0.1, 10}] but my function in place of ...
1
vote
1answer
298 views

Adjacency Matrix for an Undirected Graph

Here is an undirected graph ...
3
votes
1answer
140 views

Saving and Reading data across computers

I DumpSaved some data from my home laptop, uploaded it onto google drive and now I am trying to open it at my school computer but I am getting errors, even though the data is in the correct directory. ...
3
votes
1answer
503 views

Contour heat graph (ListContourPlot?)

I have solved 2D incompressible Navier Stokes and written out a .dat file that includes x,y,u,v,p values. I am trying to get a 2D color heat graph like this one for my data Here is what I have done ...
2
votes
1answer
1k views
2
votes
1answer
156 views

Finding the root of a nested function with small values

I have reduced an error in my program to this line of code: FindRoot[Nest[# (1 - #) k &, 1/2, 2^4] - 1/2, {k, 3.5}] It works for $2^1, 2^2, 2^3, 2^4,$ but ...
7
votes
2answers
244 views

How can this AbsoluteTime call be made faster?

I need to convert tons of date strings into absolute times. This generates an example data set of 10,000 strings: ...
1
vote
1answer
286 views

how to plot log-log histogram in Mathematica 7

I have a large array of real (positive and negative) numbers and I want to plot the histogram of it. I can use Histogram[data, "Log", PlotRange->All] but ...
-2
votes
1answer
192 views

Symbolic Simulations

I have 9 nonlinear equations and 10 unknowns. It is not possible to obtain a numeric solution but I do get a parametric solution. It is useful in my case because I want to observe how parameters (p1, ...
5
votes
4answers
210 views

Extracting sequences from a list?

Suppose I have a list of arbitrary length like {1, 2, 3, "Open", 3, 2, "Close", 9, 3, 4, "Open", 1, 0, "Close", 3, 5} and I am trying to extract the sequences ...
4
votes
0answers
156 views

Raster with ColorFunction is blank when Dynamic Updating is disabled

UPDATE Today I was having these WaveletScalogram problems again. I think this is ultimately some kind of interaction issue with Dynamic. I have narrowed it down to ...
0
votes
3answers
727 views

Pass an empty list object into a function and dynamically generate its list elements

I have another question on passing a list which needs to be generated dynamically. (Sorry for posting two questions in one day...) I did some search and found a similar post here, but I think it was ...
0
votes
1answer
144 views

Plotting a 2-D shape given its border points [duplicate]

I have the border points of a 2-D body and wish to fill its interior with a solid color. Let us say I have $N$ such points stacked in the $N \times 2$ matrix $A$ so that the first column indicates the ...
0
votes
0answers
55 views

How to monitor the progress of Importing files? [duplicate]

I want now,how much of percentage was imported,while importing any file. How can I solve this? Can anyone help me? Thank you.
2
votes
2answers
1k views

How to increase the number of minor ticks in a plot?

I want to increase the number of minor ticks in a plot, but I don't want to label them. I searched through this site and also Mathematica documentation, but I didn't find any solution yet. Could ...
3
votes
0answers
545 views

FindRoot gives a wrong solution which obviously should not be there

I got stuck on FindRoot and I didn't see any similar problem posted, so let me explain what I am trying to do and what problem I meet here. I try to find roots of a particular function, which in the ...
2
votes
1answer
900 views

Fourier transform of sampled data

I have got some impulse response data that I would like to transform via Fourier to get the amplitude-frequency characteristics of the performing loudspeaker. The ...
2
votes
2answers
189 views

Image processing - How can I apply an operation to several images at once?

I imported pictures into Mathematica, and used names for them that follow the easy scheme "name" string joined with an integer, ranging from 14 to 20. Printing these images on screen works nicely: ...
1
vote
0answers
300 views

Plotting derivatives of B-splines

I am trying to solve an electrodynamics problem numerically by using B-splines a basis function. Please don't ask me why, but if you really wanna know, here is the assignment. Using the following ...
0
votes
0answers
158 views

How can I solve this system of functional equations?

I would like to use Mathematica to find maps a, b, c, d, e, f such that ...
3
votes
2answers
210 views

How can Private functions be made completely opaque?

I want to make Private functions. From my point of view, being a Private function means that the function is not accessible from other packages. For that purpose I wrote the following code. But my ...
1
vote
1answer
149 views

Statistical analysis of data-list with recurring x-values

I have a list of data as follows with repeated x-values: ...
7
votes
3answers
532 views

How can I make private functions inside packages

I want to make private functions.for that purpose,I wrote the following code. BeginPackage["Test1`"] Begin["`Private`"] function1[x_]:=x End[] EndPackage[] I ...
1
vote
2answers
558 views

Probability density histogram with unequal bin widths

I am confused by output of Histogram and HistogramList for probability density ("PDF") when ...
4
votes
2answers
176 views

Cusom PopupMenu file selector

Lately I come across what I think not uninteresting problem which is a good exercise for the usage of Dynamic. Assume you have files in a directory structure (a ...
2
votes
1answer
213 views

How do I plot Numerical Range of two hermitian matrices

Let $A_1$ and $A_2$ be two $3\times 3$ hermitian matrices. Then their numerical range is defined as two-dimensional set \begin{align} \mathbb{S}=\{\left[u^HA_1u,u^HA_2u\right]\in ...
3
votes
1answer
280 views

Replace elements in a list

Suppose that I have a list: ...
11
votes
1answer
1k views

Write C/C++ programs calling Mathematica functions

I need to write a C/C++ program and call some functions in Mathematica especially those like Solve or NDSolve. The problem is ...
2
votes
0answers
284 views

Derivatives of list elements

Could someone explain the odd behavior of the Derivative function when drawing arguments from lists? We have, ...
6
votes
0answers
106 views

Compiled function crashes kernel when trying to list over different length arguments

I'm trying to speed up a tally/binning operation that I have to run many times. I have many lists of between 1 and 10 numbers from the range [1,5] and I want to ...
1
vote
1answer
130 views

SetPrecision with indexed variables

I have an expression as below: ...
2
votes
1answer
537 views

Infinite Expression Error from NDSolve

I am trying to solve a differential equation numerically. So I have ...
15
votes
1answer
655 views

Mathematica giving infinity as a random number!

I am trying to generate several random numbers from normal distribution using Mathematica. The following is the relevant code: ...
2
votes
3answers
216 views

Map several functions in one routine

I have several functions, let's assume they are: func1[x_]=x; func2[x_]=3*x-5; func3[x_]=0.1*x^2; and a lot more like these. For each and every one of these I ...
1
vote
1answer
216 views

List comparison in constraints for Minimize

I am trying to solve an optimization problem, a simplified version of which is as follows: ...
3
votes
0answers
95 views

shortest paths in probabilistically weighted edges? [duplicate]

I understand Mathematica can find shortest paths. However, is it also able to find the most probable paths? I mean this is a case where edges are given probabilistic wights (from 0 to 1) and the most ...
3
votes
1answer
189 views

Exploiting self-adjointness when changing basis

I am using Mathematica to analyze a real, self-adjoint matrix $H$ of the size $32 \times 32$, which comes from a physics problem. In the picture there is also a matrix $Q$ which commutes with $H$. I ...
2
votes
0answers
136 views

Nest for large value of n

I am working on a problem to find the Feigenbaum constant. In this problem I have to get $f^{2^n}(1/2)$ with $f(x) = kx(1-x)$. I use Nest to get $f^{2^n}(1/2)$ but ...
0
votes
3answers
237 views

Conjugate and simplify

I want to get a cosine from taking the real part of a complex exponential: $cos(x) = Re(exp(i x))$. What I do in Mathematica is ...
1
vote
2answers
343 views

Import large amount of data with time stamps

I have a large data file (150 000 lines) which I want to import in Mathematica. The first few lines look like this ...
2
votes
0answers
104 views

Significant platform-dependent efficiency when importing data?

I'm curious, as I understand that answer this way: If you are using a Linux derivative or something like cygwin on Windows, then this is an efficient solution for reading only the third field ...
2
votes
1answer
140 views

Solving a system of equations

Mathematica doesn't want to solve my exact system with 3 equations and 3 variables. ...
1
vote
1answer
135 views

How can I stop DiscreteMarkovProcess[] from relabeling vertices?

I'm attempting to calculate the mean first passage time between two vertices, $v_1$ and $v_2$, provided some undirected graph $G$. However, I noticed that running the following script: ...
7
votes
2answers
323 views

Problem with NIntegrate when WorkingPrecision is specified

I am trying to evaluate this integral numerically: $$ \int_0^{\infty } m \exp (-m) J_1(m){}^2 \, dm $$ Everything is OK when only the integration method is specified: ...

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