0
votes
0answers
4 views

Better use of pattern matching in replacing elements of a list

I have a list of reals and I'm replacing those which are contained in a given interval with two different values depending on wheter the selected reals are positive or negative. I came up with this ...
0
votes
0answers
17 views

Frameticks in RegionPlot

I have an issue with frameticks in region plot. Look at the code ...
-1
votes
0answers
22 views

Why is result from evaluation not simpler?

How do I define variables $\qquad u(x_m , y_n)\qquad m,n=1,2,\dots,100$ in Mathematica? $x_m, y_n$ are known and $u$ is unknown. The result I am getting is: ...
0
votes
0answers
28 views

Removing plot artifacts (SphericalPlot3D)

Using SphericalPlot3D, I find I get two types of artifact: A discontinuity in the surface reflectance at $\theta=0,2\pi$ Little edges, or perhaps gaps between ...
0
votes
0answers
26 views

NDSolve and piecewise functions

I'm trying to use NDSolve on a Pde for a function that is made up of several pretty complicated functions, most of which are themselves functions of an underlying piecewise function. When I try to ...
1
vote
2answers
59 views

how do I control the output of Reduce function?

Reduce[x*y > 50 && x*y < 100 && x < 100 && x > 1 && y > 1 && y < 50, {x, y}, Integers] what if I want ...
6
votes
0answers
50 views

Bug with Compile and Log2?

It seems that Log2 in Compile gives numerical errors (CompiledFunction::cfn) if the input is ...
2
votes
0answers
30 views

Efficiently checking whether a number is a perfect power

Goal The goal is to efficiently check whether a number is a perfect power. Attempts It is possible to check whether a number is a perfect power using ...
0
votes
0answers
32 views

Expectation of Largest Roots of Bernoulli distributed coefficient Monomials

I am interested in determining the most probable maximum values of the real roots of polynomials of form $P(x)=\sum_{k=0}^n a_{k} x^k$ where the degree $n$ will have a defined value (say 3,4,5...) and ...
0
votes
0answers
24 views

Do you know the options of RandomSeed in ClusteringComponents?

ClusteringComponents[data, 4, 1, Method -> "KMeans", DistanceFunction-> EuclideanDistance, "RandomSeed" -> 10] As above, 4 means cluster number, ...
0
votes
1answer
62 views

Substutution of Ansatz of an ODE

I am only beginning to learn to use Mathematica, and got stuck while trying to implement what is apparently a simple substitution rule. So I have a second order ODE in f, and I want to put in the ...
0
votes
0answers
38 views

Error message when using Method -> “Spline” in Interpolation

I'm using LTNOspline = Interpolation[DiscreateLT, Method -> "Hermite"] where ...
2
votes
0answers
37 views

How to find Eigenvalues of Sturm-Liouiville problem? Getting wrong Imagenary Eigenvalues

I want to find Eigenvalues of following Sturm-Liouville problem D[(2 - MA/\[Kappa][s]) q'[s], s] + W \[CapitalOmega]^2 q[s] == 0, Where [CaptialOmega^2] is ...
0
votes
2answers
33 views

TimeSeriesAggregate—reformatting the date

Compute Aggregated Statistics for a Time Series The article linked to above provides a sample of aggregating time series data. ...
3
votes
2answers
71 views
0
votes
2answers
31 views

Read timeseries data from CSV

I am new to Mathematica and have v10. I would like to you use the new TimeSeriesAggregate[tsdata, "Quarter", Total] feature to return aggregated descriptive stats. I import a number of columns of ...
0
votes
0answers
3 views

Maximum Likelihood Approach for parameter estimation of multi response data, could you provide a tutorial? [migrated]

I was trying to fit the parameters a time dependent system coupled of ODES relate to a kinetic experiment with multi response data. example: A->B+H A+H->C+H A->D dcA(t)/dt=-k1Ca(t)-k2Ca(t)*Ch(t)-k3*Ca(...
-2
votes
0answers
25 views

Plotting Graph having coloured visuals and coloured lines [on hold]

Somebody please tell me what is "fondo" and "funcero" Plus I'm having a great difficulty in plotting a graph, my graph line doesn't show up. frustrated
1
vote
0answers
27 views

Training Hidden Markov Models using Mathematica

I have created a Hidden Markov Process with an initial probability vector, emission and transmission matrices. ...
0
votes
0answers
36 views

Mapping a List: Functions in Mathematica [on hold]

I have the code: ...
0
votes
1answer
28 views

How can I compute the difference in Y-axis values between data sets with similar X-values

I am new to Mathematica, so this might be a very basic question; however, I cannot find a solution to this and it is taking me very long. For my research I am probing the photoluminescence response ...
3
votes
4answers
257 views

Lists in Mathematica

I have a list of the form: { {0.185794, {α -> 5.8794, χ -> 3.14159}} ,{0.206365, {α -> 6.07943, χ -> 3.14159}} } How can I transform this list such ...
3
votes
2answers
94 views

Delete elements from a list

I have two lists, for example s={{1,3,2},{1,3,2},{2,3,1},{3,1},{2,3,1}}; c={{3},{1,2},{3}}; First element of c means that ...
2
votes
1answer
86 views

Need urgent help correcting error on Mathematica prototype

Sound synthesizers, both digital and analog, often include a parameter section for shaping the amplitude of a sound wave over time. This parameter section is commonly known as an "ADSR EG" (attack, ...
3
votes
1answer
50 views

NDSolve Step Size Effectively Zero

I'm trying to solve a PDE for a function of 2 variables. The most accurate parameterizations of this equation are very unwieldy and involve numerous piecewise elements, and so right now I'm trying to ...
11
votes
1answer
123 views

Bad interaction between Join and ListPlot (or Plot)

When you write this code: tab = {{1, 1}}; tab = Join[tab, {{2,2}}]; you expect to get the following table: {{1, 1}, {2, 2}} ...
0
votes
0answers
39 views

Key mapping an association applied to a distribution

I am attempting to import data from a database, group it according to a given identification parameter, get it's statistically relevant information, and then export it as a JSON object for ...
2
votes
1answer
62 views

Co-ordinate Points on a 3D Plot

I have a 3D graph: I want to figure out the values of the variable in the horizontal axes for which the graph has the highest value -- seeing the vertical axis, the value of variables where plot ...
4
votes
1answer
42 views

Installing MATLink without administrator privileges

This web page says that MATLink requires admin rights. First two steps to link Mathematica and MATLAB are: Add MATLAB's bin\win64 directory (bin\win32 for 32-bit versions) to the operating system's ...
1
vote
2answers
131 views

Create a 900x900 matrix and diagonalize it

I have to create a 900x900 matrix and then diagonalize it. It is something similar to the below matrix. The value of a,b,c,d....up to 900 values (which are the first column and row) are the number. ...
0
votes
1answer
27 views

NDSolve swapping between solution branches to stay positive

I have a differential equation that I wish to solve, with the requirement that my independent variable must stay positive, but do not require it to remain differentiable. My equation comes from ...
2
votes
1answer
49 views

Evaluating a list of randomly sampled triplets with a function of three variables

I'm new to Mathematica. I need to generate a list of 1000 triplets of random numbers {r, p, t}, so that 0 < r < 1, ...
2
votes
1answer
70 views

Loops and Graphics in Mathematica

I want to create a loop in Mathematica such that it creats multiple graphs for me. For example, I have a command of the form: ...
6
votes
1answer
45 views

Multiple documentation notebooks open at the same time

Is it possible to view multiple documentation notebooks at the same time without launching multiple kernels? I'm sure it must be possible.
1
vote
1answer
68 views

Unexpected behaviour of MomentOfInertia

The problem I expected Mathematica to solve rather easily is that of the calculus of a moment of inertia of a "c" section defined by the following Polygon: ...
4
votes
2answers
34 views

Drawing a GraphPlot by preserving the structure of the graph

For eg. GraphPlot[{1 -> 2, 2 -> 1, 3 -> 1, 3 -> 2, 4 -> 1, 4 -> 2, 4 -> 4}, VertexLabeling -> True] Then If I remove the edge (say ...
0
votes
0answers
24 views

ImplicitRegion RegionPlot fails for circle in 10.4.1 [duplicate]

This must have worked at some point, because the documentation for ImplicitRegion has the right picture. But when I evaluate ...
0
votes
1answer
55 views

Expand a complicated polynomial

I am entirely new to Mathematica. I am wondering whether Mathematica can help me to expand expression like the following $$f(x_1,\dots, x_n) = \left(\sum_i x_i\sum_j x_ix_j^2\right)^3\left(\sum_{i,...
5
votes
2answers
71 views

Adding arrowheads to a piecewise function

I have: ...
2
votes
2answers
98 views

Automatically isolate the linear part of my data so that I can find its gradient?

I have some data plotted which is of bacterial growth curves, I have 96 sets of growth curves and I am wondering if there is a quick way to extract the straight line area of my growth curves in each ...
-1
votes
0answers
22 views

How To Sort BarChart Data Based On the Selected Column

This sample code works fine for the category of StarData selected. What I would like to do is sort the data based on which BarChart is selected. ...
0
votes
0answers
34 views
1
vote
2answers
50 views
2
votes
1answer
44 views

How to set proper time zone for weather data

I am running a query to pull historical temperature readings from Los Angeles using the following query: ...
3
votes
1answer
98 views

Discrepancy between Matlab and Mathematica

What is the difference between how Matlab and Mathematica solve State-Space and Transfer Function models? I have a $16 \times 16$ state space system for which I am calculating transfer function. ...
0
votes
0answers
11 views

Print joined string with variable superscript [duplicate]

I like to join some strings which I then like to print. A substring contains a number that I like to be printed in scientific format. An example to clearify: ...
1
vote
1answer
53 views

Distribute operator on functions

I wrote this code: ...
0
votes
0answers
27 views

How do I do Cauchy product of infinite series?

I have two series and want their Cauchy product series as a result. For instance, I want to multiply Sum[1,{x,0,Infinity}] to Sum[2,{x,0,Infinity}] The directConvolve method does not work, ...
0
votes
0answers
30 views

Why Mathematica does not Maximize when using parameter

I have recently started using Mathematica and I have got a question using it. I would appreciate if one could help me figuring out how to handle it. I have the following simple maximisation code <...
0
votes
0answers
35 views

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