3
votes
5answers
168 views

Select a certain row among the duplicates

I have the following problem: I have a (a lot)*3 table, meaning that I have 3 columns, say X, Y and Z, with real values. In this table some of the rows have the same (X,Y) values, but with different ...
-1
votes
1answer
110 views

Laplace equation

I tried to run this code, but it doesn't work for NDSolve ...
1
vote
1answer
130 views

FindMinimum function does not produce minimum from near point

Using my simple program and I would like to find such matrix elements that minimize difference of their eigenvalues. ...
0
votes
1answer
79 views

How to extract info from Association? [duplicate]

How can one extract a list of keys and a list of values from the association? e.g. as = <|a->1, b->2, c->3, d->4|> ...
4
votes
1answer
306 views

How do I produce a BarLegend with the default coloring of a ContourPlot, using Legended?

I have a series of ContourPlots that I want to compare in a GraphicsRow environment. I want to add a single Legend for all three plots. Also, I really like the standard color scheme of the ...
1
vote
0answers
42 views

How does LinearModelFit handle cases where the design matrix rank is lower than the model terms?

So, I understand what this error means: ...
4
votes
0answers
101 views

Using indexed array elements as integration dummy variables with EvaluationMonitor. Bug?

As part of a routine that must cope with integration of varying numbers of dimensions, I would like to use indexed variable names (e.g., x[0], x[1],...) as dummy integration variables. However, it ...
7
votes
1answer
135 views

Is It Safe to Remove the Documentation Notebooks?

I am running Mathematica 10 on linux and noted that the directories containing Mathematica's documentation come to over 3GB. Am I safe to delete these directories without affecting how Mathematica ...
5
votes
3answers
140 views

How to label only leaves in TreeForm?

I have a Huffman encoding represented as a list in the following manner: encoding = {{{w, d}, {o, s}}, {{{e, q}, a}, {i, j}}}; This means that ...
1
vote
2answers
236 views

How to solve for “k”

So the question is given that the atmospheric pressure is modelled by the differential equation p'[h]=-kp[h], p[0]=1013, p[20]=50. find k and comstant of integration. My code was: ...
3
votes
1answer
67 views

Do Dataset functions get applied to rows in order?

If I have a dataset ds and perform an operation such as ds[All, f] does f get applied in the order the rows exist (the order they were placed into the dataset or as the result of a SortBy clause) or ...
5
votes
0answers
55 views

Built-in way to handle uncertainty in measurment and physical constants?

Is there a built-in or fairly elegant way to handle uncertainties in measurement data and/or physical constants? For instance, the 2010 CODATA for the elementary charge is given as $\mathsf{1.602 176 ...
6
votes
1answer
138 views

Axis label obscuring tick label

I have a plot and have applied options to customize the axis labels and ticks. ...
0
votes
2answers
182 views

How to remove unnecessary brackets in one formula

I have some string,like "3+(3*(2+5))", obvious that some brackets are unnecessary. It can write like "3+3*(2+5)", so I try to use Inactive. ...
1
vote
1answer
58 views

How to label 3D plot with specific variables

I have a plot of a function depending on two variables called l2 and l3. However, I would like to label the axes of the plot ...
4
votes
1answer
396 views

Lyapunov exponent plot

I am trying to create a Lyapunov exponent plot as a function of $\alpha$ for two functions: $$ f(x) = (\alpha + 1)x - \alpha x^{3} $$ and a piecewise function given by following Mathematica code: ...
2
votes
2answers
96 views

Extracting coordinates from a ListLinePlot

I used an iterative method to resolve equations, then i plotted the results using ListLinePlot. Unfortunately, now I need to use some of the data that was plot. I know the X-coordinate, and need to ...
5
votes
2answers
238 views

Double improper integral

I am trying to compute the following double integral: Integrate[(r BesselJ[0, r])/( 2 (r^2 + z^2)^(1/2)), {z, -Infinity, Infinity}, {r, 0, Infinity}] Which ...
0
votes
1answer
210 views

Plotting results of NIntegrate with variable integration limit

I have tried to use NIntegrate with variable limits and compute the following ...
0
votes
2answers
47 views

solving ode and plotting solution vs time

I'm currently trying to solve this system of two ode's and can't seem to be able to solve them. I am new to coding, so I don't know where I could have done a mistake. I'm attaching the code which I ...
1
vote
1answer
112 views

Importing a 3D table from excel

I have a 3D table that I'm able to plot using ListPlot3D, but when I export the table to an excel file and try to import the saved data, the format is different. The imported table seems to have ...
1
vote
1answer
74 views

Joining sub-lists nested two levels deep in a list [closed]

I have an obviously easy task, but I can't do it, and I could not find a solution by searching the site. I have a list as follows: ...
0
votes
0answers
73 views

Deciphering output messages using Solve

I'm trying to solve the following system. The error messages I'm getting suggest that there may not be a solution [my desired result], but I'm not sure if there could be something else going on. The ...
1
vote
1answer
302 views

Interpreting P-Value on ParameterTable

When using LinearModelFit[] we can generate a table of parameter values and statistics for the corresponding model using the property "ParameterTable". Looking in the documentation I can't find an ...
0
votes
0answers
42 views

how to export to html using multiple css

I have to convert many notebooks to HTML so I'm trying to create all possible rules so to minimize the manual correction. The html pages need to have multiple css links, something like the following ...
11
votes
6answers
815 views

How do I draw a polygon defined by a list of data points?

I am attempting to make a 3D model of a device defined by a list of {x,y,z} points, digitized from a 2D image. The z coordinate is defined in mma. What I tried so far: ...
2
votes
1answer
85 views

Eliminating the backward play in a SWF export of Manipulate

I find that the Export of Manipuate contains backforward play, see a simplified example: Export["try.swf", Manipulate[ Plot[Sin[2 x + φ], {x, 0, 10}], {φ, 0, 2 π}]] You can see the problem in ...
7
votes
2answers
408 views

Find fit of an experimental PDF

After quite some struggle, I managed to put up a code that is syntaxically correct. The goal is to find the parameters for a gamma distribution that best match experimental data. The data is a set of ...
0
votes
1answer
101 views

Using Manipulate to make a 3D plot of a function of three variables [closed]

I have a function $S = S(\alpha,\tau,q)$. I am interested in plotting a 3DPlot of $S(q,\tau)$ for a given value of $\alpha$. However, I would like to visualize this by manipulating $\alpha$ with the ...
0
votes
1answer
53 views

Cannot determine, what this partw error message is aiming at …

So i am trying to plot the magnetic vector field surrounding a "flat conducting cable" (don't know the proper english expression). This is the "code" (there are some constants in the analytic ...
13
votes
2answers
420 views

Analyze touching particles with holes in a microscopic image

I am looking for an easy method to count individual particles in a microscopic image. It is quite difficult for Mathematica to detect them, because they are touching each other. I am quite a beginner ...
3
votes
1answer
82 views

How to set ExportOptions for custom HTML exports

I need to customize some HTML tags when exporting a Mathematica notebook to HTML. I have to use the File ► Save As… FrontEnd token and not ...
1
vote
2answers
113 views

How to find total distance covered when I have a list of GeoPositions?

So I have a list of GeoPositions and I need to find the distance covered in that order? I know I can find the distance from each city and then add them all up but I was wondering if there is any ...
1
vote
0answers
56 views

How to speed up geometric Resolve query involving $\exists$ and $\forall$?

I would want to test connectedness of semialgebraic sets with naive code like this: ...
1
vote
2answers
156 views

Find recurrence relation for a sum

Let's say I want to find a recursive equation for an exponentially weighted moving average EV[t_]:=(a-1)/(a^t-1)*Sum[a^(t-i)*x[i],{i,1,t}] I can do that manually ...
0
votes
0answers
60 views

RSolve with two variables

I want to find $a(m,n)$ with $~a(m,n)=\alpha * a(m-1,n) + \beta * a(m,n-1)$, where $\alpha$ and $\beta$ are constants. I expect an explicit $a(m,n)$ represented by $a(0,j),~j=1,2,\cdots,n$ and ...
1
vote
1answer
52 views

Issue when using Ticks and Frame [closed]

...
0
votes
1answer
91 views

My simulation is not never finishing and it is taking so much time?

I am running simple code which involves calculation of two first order differential equations.It is taking so much time and i am unable to get the results as the simulation is never finishing. ...
3
votes
1answer
228 views

How to create a bar chart from a list of heights *and* bin delimiter positions?

Basically, I'm trying to produce the same output that Histogram[giganticList] would produce, but starting from the output of ...
10
votes
1answer
454 views

Compute inverse Laplace transform with Integrate

Since inverse Laplace transform is just an integral, while we already have InverseLaplaceTransform built in, can we compute it with ...
7
votes
1answer
194 views

Difficulty in getting correct Gaussian curve for diffusion of point source

I want to solve diffusion of a point source numerically and check it against analytical solution. first I define initial profile, ...
1
vote
1answer
77 views

Incompatibility of Append and NumberForm? [closed]

Consider the code list = {.12, .23, .34}; Append[Round[list, .1], 10] Append[NumberForm[list, 1], 10] The use of Round returns the expected result ...
0
votes
1answer
77 views

Animation stays blank during animation

In attempting to answer this question about animating a rolling disk, I constructed a ParametricPlot to Animate. The plot looks ...
1
vote
0answers
69 views

Why are my 3D plots getting inverted? [closed]

For some reason, all 3D plots that I make in Mathematica 9 get inverted in both the image and the axes. For example, using the simple plot: ...
0
votes
1answer
86 views

Plot curves like equation problems

I'm proving to plot and edit some wolfram alpha laminae, but when I try it, I don't have any result, for example: (from:http://blog.wolframalpha.com/data/uploads/2013/07/Curvespt31.cdf) ...
1
vote
0answers
64 views

Multiplying two sets of data (x,y values, but different x density) followed by integration of the product

I've been trying to do this by myself today, but no luck yet. Please, see attached image. Basically, I do have two data sets A (x1,y1) and ...
1
vote
2answers
199 views

Rolling Disk Animation

I am trying to create an animation in Mathematica of a rolling disk outside a disk of equal radius. The following coding is what I have tried but without the one circle staying in a fixed position I ...
1
vote
2answers
113 views

Plot The volume of a cylinder between a cone and XY

I want to plot the volume of a cylinder between a cone and the plane XY The equation of the cone is $z$ $=$ $\sqrt{x^2 + y^2}$ and the cylinder equation $y^2 - 2y + x^2 = 0 $ I am using the ...
10
votes
2answers
974 views

How to remove outliers from data

I have a data with noise which some times includes significant outliers. The position of the outliers are random. For example: ...
0
votes
0answers
38 views

How to solve coupled first-order ODE with vectors?

m * v'[t] = q * (E + v x B) using the following: B = (0,0,B0), E=(Eperp,0,Ez). How would I find the general solution of ...

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