0
votes
0answers
6 views

Mathematica on Linux Ubuntu: antialiasing issue

I'm working on a webMathematica application using a linux server (Ubuntu 12.0.4 LTS) with Xtightvnc. Even though the system administrator has done all the possible to set the anti-alising features, we ...
0
votes
1answer
12 views

SIR Model with Dynamic module

I am having trouble with generating a parametric plot with the following code: ...
1
vote
4answers
26 views

How can I convert a Piecewise into a nested If?

For later conversion into a programming language where if is the only conditional construct, I would like to convert a Piecewise ...
-1
votes
1answer
22 views

Solve For X inside arc-cos function (with division) [on hold]

Very basic but I've been stuck for more than 12 hours trying to solver this equation 20=360/(arccos(X/3200)*2) Can anyone solve X? and explain what exactly you ...
1
vote
1answer
22 views

RecurrenceTable [on hold]

I got an error saying ...
0
votes
0answers
33 views

How can I import a pickled file?

I have a file generated from a python script that dumped a dataset into a pickle "data.pickle", I am at a loss as to how to Import the file, since "PICKLE" is not ...
0
votes
1answer
9 views

Assigning some results after a solve procedure to the coefficients of a matrix

I have a matrix M[3,3]. After a solve procedure, I obtained these results. {{M[1, 2] -> Cos[ψ[t]], M[1, 3] -> 0, M[2, 3] -> 0, Cos[θ[t]] -> M[3, 1], M[3, 2] -> 0, M[3, 3] -> 1, M[2, 1] -> ...
0
votes
0answers
14 views

Extract the divergent/bounded part of a certain expression

Consider I have a power series which is function of $x$. A part of this expression is bounded when $x->\infty$, some remainder is on the other hand divergent when $x$ goes to infinity. What is the ...
2
votes
4answers
37 views

Extract a part of Series

If I have the output of Series, in terms of powers of my variable $x$, what is the quickest way to extract a part of the series, say for example the terms from $x^2$ to $x^5$, excluding those with ...
0
votes
1answer
18 views

Extract a term of `Series` output

Say I have the output of series, with all the coefficients of the different powers of my variable $x$. What is the quickest way of extracting the coefficient of the $n$-th power of $x$?
0
votes
1answer
36 views

Interpolating a non-continuous set of points

I'm trying to create a pure function that I can feed into OutputResponse[ ] as the input u[t]. In order to do this, I've written code to create a square wave pulse train in the form of a collection of ...
1
vote
1answer
29 views

How to do n-fold cross validation with Classify?

Other machine learning libraries have utilities to generate indices that can be used to generate dataset splits according to different cross validation strategies. How do I tell ...
0
votes
0answers
29 views

How to use If to compare a function

I'm trying to write a Manipulate demonstration where you can select one of a number of functions. At one point I need to test if the function chosen is a particular one, and it seems to work if the ...
0
votes
0answers
28 views

Calculating the rank of an abstract matrix

I'm trying to compute the rank of a 4x4 matrix with 4 parameters and 2 variables. I tried to calculate its rank under some assumptions on those conditions and I kept getting rank 4. So I did an ...
0
votes
0answers
13 views

Somebody imported .mdt files (3d graphics) in Mathematica?

Hello maybe someone did or import this format in math for subsequent presentation in 3D
0
votes
0answers
17 views

Generating a C/C++ Code with a Non-Linear Vector Function [on hold]

In Mathematica, I have a vector RES = {f1,f2,f3, ..., f7} where f1 thru f7 are non-linear functions of my degrees of freedom: a1 thru a7. I know that I can use: ...
0
votes
0answers
29 views

Estimating inherent parameters for projectile under influence of wind in 3D based on measured data

The goal of this is to be able to estimate the drag constant $k$ and mass $m$ for a projectile based on measured landing coordinates $P$, start speed $v$ and launch angles $\varphi$ and $\theta$ ...
7
votes
5answers
89 views

How to Map a function with HoldAll attribute

First of all, I'm not sure about the title of this question, so please correct me if there is any title more sensible than mine. The problem is the following: I have a function f that checks if a ...
0
votes
1answer
28 views

Mathematica not seeing my environment/system variables

I'm trying to access my environment variables in Mathematica, but I get a Failed result every time. For example: $ echo $USER jlconlin but in Mathematica I do: ...
1
vote
2answers
43 views

Infinite Sum with exclusion

From another question I tried to implement something like: Sum[r^(1 - l[n]) DD[n], {n, Complement[Range[1, Infinity], {4}]}] but this does not work because ...
2
votes
3answers
196 views

Median household income for each county in Maryland

I found that Wolfram|Alpha knows the median household income for every county in the US. I wanted to get a list of all counties in Maryland, and the median income in each county. The only way I could ...
1
vote
1answer
29 views

Truncate a sum in a 'smart' way

Consider a series like this: $$\sum_{n=1}^{\infty} (c_n r^{2-n/2}+d_n r^{-n/2})$$ Sum[c[n]r^(2-n/2)+d[n]r^(-n/2),{n,Infinity}] I want, now, to keep only the ...
3
votes
0answers
39 views

Launching 49+ local kernels fails in 10.0.2

I do large-ish parallel computations in Mathematica on quad socket 16 core nodes (64 physical cores). In version 8.x, LaunchKernels[64] works reliably. In version 10.0.2, LaunchKernels[48] works ...
0
votes
0answers
13 views

html embedded cdf does not print

Upon exporting an nb file to an embedded CDF for viewing in an html file, no print image is displayed when I attempt to print the web page. Given that the CDF Web Development Wizard also produces a ...
0
votes
0answers
63 views

How to solve a heat flow equation [on hold]

I am a beginner in Mathematica. I was wondering if anyone could give me some pointers as to how to solve following type of equations. During a particular time interval, ...
2
votes
2answers
103 views

Please help translate regular expression to StringExpression

I am familiar with regular expressions in other languages (e.g., Perl, Python, ViM), but the Mathematica StringExpression is baffling me. I'd like to match strings ...
0
votes
0answers
40 views

Don't understand why my Do-loop is misbehaving [on hold]

I have a 2D array, initialized by array = ConstantArray[0, {10, 1000}] and I want to assign numerical values to ...
0
votes
1answer
52 views

several plots at once

I have several files what i would like to plot at once, they are .dat files and they have names as a numerical sequence from 1 to 4 (they are about a hundred but for the example 4 are ok) so i use ...
0
votes
1answer
34 views

Series identity with binomial coefficients [duplicate]

I have this apparently simple equation: ...
2
votes
3answers
82 views

Find the volume & weight of a US$4,000,000 gold ingot

The other day I read that $4,000,000 worth of gold was stolen from a truck. I was wondering how much it would it weigh, and what would be the volume. Sounds like a good problem for Wolfram|Alpha or ...
0
votes
0answers
34 views

Unknown number of variables in a logical statement [on hold]

Resolve[ ForAll[{i, y[i]}, Implies[i >= 0 && i < 3 && Implies[i < 3, y[i] > 0], Sum[y[i], {i, 0, 2}]>0]]] returns ...
0
votes
2answers
29 views

Selecting elements from a list [duplicate]

I have the following array of numbers: a = {{0, 2, 5}, {3, 5, 1}, {4, 0, 5}, {8, 3, 4}, {0, 8, 6}}; then I make a list of the first row with ...
3
votes
2answers
54 views

CDF of experimental data

Here is data.csv: ...
0
votes
1answer
50 views

Random numbers genereated from sum of multiple Gaussian distributions [on hold]

Does anyone know if it's possible using Mathematica 10 to generate random numbers from a dsitribution that is a sum of Gaussian distributions? Or if there are packages that are available that is ...
0
votes
0answers
46 views

Improve performance of processing transactions in a large file

I want to work with a table which has 296,705 transactionslines and 172,147 transactions. ...
0
votes
1answer
41 views

Importing 2D array of image

Suppose images = {{1.jpg,2.jpg},{3.jpg,4.jpg}} Now I try to import all of them in level 2, Map[Import[#],image,{2}] Why Mathematica says it is invalid file? (error= Import::chtype)
0
votes
1answer
32 views

NDSolve emitting error message NDSolve::ndnum [on hold]

I am trying to solve this system equn1 = ψ'[x] == - Elec[x] equn2 = Elec'[x] == - ((di/ a)^2)[(Exp[ψ[x]] - (x/(xoi*Sqrt[-ψ[x]])))] For that I am using ...
-2
votes
0answers
20 views

Finding a function to map one set of numbers to another on a curved line? [on hold]

I have a set of random numbers and I have to generate a new set of random numbers from these numbers. So if x represents my original number then the new number would be y. Here is what I know so far ...
-2
votes
0answers
15 views

Independence Number of Graphs [on hold]

Suppose $\alpha(G)\leq\alpha(H)$ where $G$ and $H$ are graphs, and $\alpha(.)$ is the independence number of graph. Is the following statement true? $\alpha(G\boxtimes G) \leq \alpha(H\boxtimes H)$ ...
1
vote
1answer
37 views

little problem of Thread, List head of second argument

Thread[f[{a, b, c}, 0]] (* {f[a,0],f[b,0],f[c,0]} *) Thread[f[{a, b, c}, pp[0]]] (* {f[a,pp[0]],f[b,pp[0]],f[c,pp[0]]} *) Howerver, the head of pp ...
0
votes
2answers
39 views

Nonlinear matrix equation solving in Mathematica

is it possible to solve below equation in Mathematica? A.X+B.Exp[X]==C A, B are square ...
2
votes
3answers
76 views

Finding minimum of a list of pairs

Sometimes I need to find the Min of a list, whose elements are lists (say of two elements, a pair). Given that Min does not have the option to indicate a sorting function like Sort, I elaborated the ...
0
votes
1answer
41 views

Table yields unexpected result [duplicate]

I evaluated Table[#[[i]] &, {i, 1, 5}] and got ...
0
votes
0answers
26 views

How to implement Wolfram|Alpha like interface in Mathematica? [on hold]

I want to write a good-looking function to calculate something. I see that WolframAlpha["gravitational acceleration"] Returns a calculation field looks good, ...
1
vote
1answer
47 views

Combine 3D plots into one with Manipulate and different region plots

The following script generates two plots in a row, both of them controlled by Manipulate. I would like to combine them together in one. The problem I don't know how to solve is that the plotting ...
1
vote
1answer
28 views

Changing Function Domain of Fourier Series

If I write FourierSinSeries[x, x, 10] Mathematica will output the first 10 terms of the Fourier Sine Series f(x) = x defined for 0 < x < Pi. How do I output the the Fourier Sine Series for ...
0
votes
1answer
32 views

How to Clear derivative definitions?

I can't find a Clear or ClearAll command that gets rid of Derivative definitions I created. this code: ...
0
votes
0answers
23 views

FindRoot[rhs==lhs, {x,x1,x2}] Vs FindRoot[rhs==lhs,{x,x1}]

What is the difference between these two commands: FindRoot[rhs==lhs, {x,x1,x2}] and FindRoot[rhs==lhs,{x,x1}] They give ...
1
vote
1answer
36 views

how to reduce noise in time series data?how to do interpolation for missing value data?

i have done this coding to plot the data. the problem is some value is missing for certain date and the graph is not smooth and noisy. one way to smooth the data is by interpolation but i dont know ...
0
votes
3answers
35 views

Solving system of equations with complex numbers [on hold]

I have two equations and two unknowns. The coefficients are complex. How do I solve them using matrices? Or any other method? Here is an example: Trying to find X and Y ...

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