6
votes
1answer
106 views

Error messages from TensorContract and TensorReduce

I am struggling with a few errors when using symbolic tensors. I am using mathematica 9.0.1.0, linux x86. The following code generates what seems to me an incorrect tensor, this is the smallest ...
4
votes
4answers
242 views

Sublist pattern matching

Is there any way to simplify the following pattern: {p___, {a___, x_, x_, b___}, q___} :> {p, {a, x, b}, q} Ie. where I remove duplicated elements within ...
0
votes
1answer
238 views

How to work with decimals (e.g. 0.95) instead of fractions (95/100) and get the same result

In my code I have a function, F, that depends on several parameters, say a,b,c: F(a,b,c). I need to give a grid of values to a,b and c to obtain the value of F. My grid of values are decimal ...
2
votes
3answers
246 views

How to use the same PlotRange and the same PlotLabel size for a sequence of Graphics?

I wish to use ListAnimate to show a sequence of plots with different plot ranges and differently sized plot lables, all unknown in advance, in a way that keeps the ...
17
votes
3answers
549 views

Applying different functions to different columns of a Dataset

Suppose I have different functions: Total, Mean and Max and the following ...
7
votes
2answers
306 views

Connecting to LeapMotion

Thanks to those who helped me with my previous question. I will help others too where I can. In the meantime I have a general question whether anyone has had success connecting Mathematica to the ...
0
votes
2answers
185 views

Time value of Money Functions combined

I am trying to combine multiple functions into one. I have defined following functions: (PV refers to Present value, FV refers to Future value, i or IPER refers to interest per period, pmt refers to ...
2
votes
3answers
66 views

Reconstructing an expression [duplicate]

I have a nested expression like this one expr = Tan[Sin[Cos[x]]]; I can deconstruct it with ...
5
votes
4answers
234 views

Finding the position of a single array in a list of arrays that contains wildcard variables

Consider two lists: superList = {{wc,wc,1,wc,wc}, {wc, wc,2, wc, wc}, {wc, wc, 3, wc, wc}, {wc, wc, 4, wc, wc}}; littleList = {a,b,3,c,25}; In ...
1
vote
0answers
149 views

stacking images [closed]

I would like to take a series of night sky photographic images taken sequentially and enhance dim stars in a single image. This is a standard function in astronomical image processing packages, but I ...
1
vote
1answer
234 views

Estimating Confidence Interval Variance covariance matrix from weibull distribution

In The following Example 50 obs . I estimated distribution parameters (by point) but *i want to estimate parameters by confidence interval and calculate covariance matrix i need help * ...
2
votes
1answer
303 views

Choosing The Best Fitted Probability Distribution Model

The following Example 20 Obs and i used Goodness of fit test with Exponential distribution, another time with Weibull distribution and third time with Pareto distribution .All of them are significant ...
3
votes
2answers
111 views

The conflated two uses of SameTest within Intersection

Intersection works as expected in this case... a = Range[1,5];b=Range[3,7]; Intersection[a,b] giving... {3,4,5} However if ...
10
votes
2answers
263 views

Reading grave stone letters in an image

(Click on image to enlarge) (Click on image to enlarge) Is there an image processing technique that would aid in reading the letters and numbers on a grave headstone? Most stones are etched ...
7
votes
3answers
424 views

Spacing the elements in a bar chart with error bars

In the Add-Error-Bars-to-Charts-and-Plots How-To in the Mathematica documentation, a function ErrorBar is given: ...
1
vote
1answer
159 views

How to evaluate complex numerical integral in mathematica?

I have an integral of the form \begin{align} F(\omega) = \int_0^{\infty} f(s,\omega) \mathrm{d}s \end{align} which I would like to numerically evaluate and plot for a range of $\omega \in ...
1
vote
1answer
600 views

Solving Fredholm Equation of the first kind [duplicate]

I want to numerically solve Fredholm integral equations of the first kind, equations of the form $$g(t)=\int_a^b K(t,s)f(s)\,\mathrm{d}s$$ where we know the functions $K(t,s)$ and $g(t)$ and seek to ...
1
vote
1answer
115 views

Ticks Label in 3Dplot in Mathematica

In 3DListPlot, I am plotting data such that I have discretized a contineous function. While plotting, I automatically get the ticks labeling, marking the discrete points. I want to replace the ...
12
votes
0answers
213 views

Plotting extra parametric axes

We are trying to plot a figure as below from data points. This version is a postprocessed plot (in Illustrator) just to obtain the skew axes. The rest is plotted with ...
10
votes
1answer
212 views

Notebook's WindowSize interference with contents' Dynamic ImageSizes

Bug introduced in 8 or earlier and persists through 10.4.0 or later Consider the following MWE: ...
6
votes
6answers
358 views

Total by a criteria

I am developing a weighted KNN algorithm. In a step, I need to do the sum of weights of each class. For example: ...
5
votes
2answers
157 views

Non sequitur in documentation of MemberQ

Mr.Wizard's question about MemberQ and FreeQ got me to re-read the documentation for those functions. I find I don't understand ...
0
votes
3answers
264 views

Importing multiple files with a loop

I have 101 files with data that I want to import into Mathematica. All the file names are numbered as follows datafile.20.0000.out, datafile.20.1000.out, datafile.20.2000.out and so on. I used the ...
5
votes
3answers
516 views

What is the best way to write a polynomial in the Bernstein basis?

The Bernstein basis of polynomials of degree $n$ is the set of polynomials of the form $$\binom{n}{k} t^{n-k}(1-t)^k$$ where $0 \leq k \leq n$. What is the best way to transform a given polynomial ...
3
votes
1answer
206 views

Importing data from Matlab, using data in “NSolve” and send the results back to Matlab

I have generated an image processing code in Matlab. It has several subroutines and in one of them, I should solve a system of 7 nonlinear equations. I use "fsolve" in Matlab to solve this system, ...
3
votes
1answer
67 views

How can I show the inline parameter list with a keybinding while typing a function?

Is there a way to invoke either of these contextual menu buttons that popup when typing? I don't really like to move my hand over to the mouse just to see in what order the parameters are supposed ...
3
votes
1answer
150 views

Fast list interpolation over common x,y for multiple variables

I have a (long, >50K elements) unstructured list with a header similar to; AList[[1]] = {x,y,z,var1,var2,var3,var4,...,varN} I want to interpolate z, var1, var2, ...
0
votes
0answers
513 views

Poincare Section of an Hamiltonian

I'm in desire to plot the Poincare Section of a differential equation defined by a hamiltonian system. The hamiltonian is as follow: ...
5
votes
2answers
375 views

Converting image data to array

I'd like to convert these images to a list or array in order to graph them. I know some rows are unreadable, but it doesn't really matter. So I tried using ...
3
votes
1answer
378 views

Find the NullSpace of a matrix whose determinant is “almost” zero

If $A$ is a matrix such that $\det(A)=0$, it is easy to get a basis of the kernel of $A$ with NullSpace[A]. Now let's consider a matrix $B$, function of a ...
3
votes
1answer
92 views

TeXForm producing weird outputs

When executing TeXForm[ElementData[8, "ElectronConfigurationString"]] the resulting TeX markup appears to include some ...
17
votes
1answer
195 views

A bug in the overloading of MemberQ and FreeQ for Association?

Bug introduced in 10.0.0 and fixed in 10.1.0. While answering Pattern match for nested Association I came across behavior of MemberQ and ...
1
vote
2answers
118 views

text analysis: split document in seperated lines

For a text analysis I want to split a large document in seperated lines. Then I want to calculated for example the average number of words. A example of the document is the following: ...
1
vote
1answer
235 views

Using mathematica to understand linear algebra

What is the reason why this does not work, as you can see there is three unknown and I want to see the planes. I have looked through the user manual but there is something that I am not realising! ...
7
votes
1answer
2k views

Get expression type?

Is there a built in function that distinguishes between different kinds of variables? I mean something like: ...
4
votes
2answers
209 views

Looping through a list partition

I got the following list and I would like to loop and partition this list in the following way. ...
2
votes
0answers
194 views

Mathematica not evaluating q derivative of Jacobi theta function

Jacobi theta functions, $\theta_a(u,q)$ for $a=1,2,3,4$ are defined in the unit disk $|q|<1$. For some reason that I would like to understand, Mathematica does not evaluate numerically the $q$ ...
0
votes
0answers
62 views

Is there a command like meshgrid in Mathematica? [duplicate]

Just like the title, I need to do a meshgrid in Mathematica, is there any command like that?
1
vote
0answers
150 views

the default option of NDSolve

How should I find out what the default value of Accuracy and Precision is in the NDSolve? I have a pde that when I asked it to solve for me the equation with a special Accuracy and precision it gave ...
7
votes
2answers
268 views

Catching error in middle of evaluation of compiled function

I have programmed and Compileed a complicated numerical function. The function has singularities (i.e. are infinite) at certain input numerical values. I need to ...
4
votes
0answers
252 views

C compiler options passed by Mathematica

What options can be used for compilation using Compile or CreateExecutable in Mathematica and where can one find details on the ...
3
votes
2answers
164 views

Problem with old code for a Calabi-Yau manifold

I would like to draw a Calabi-Yau space in Mathematica. From Andrew J. Hanson's paper (page 6) about this topic, I got the following code, which just does not show anything at all in my Mathematica ...
1
vote
1answer
95 views

Strange functioning of RegionPlot with Reduce's output

I have defined this two quantities: f = (-b + Sqrt[b^2 + 4 a])/(2 a) g = (-b - Sqrt[b^2 + 4 a])/(2 a) and I want to solve this system in function of $a$, for ...
16
votes
0answers
190 views

Calling Sage functions from Mathematica

I recently found a very useful open-source math software called Sage, which provides many useful functions lacking in Mathematica. Since I'm more used to the Mathematica language instead of the ...
21
votes
1answer
276 views

Make my data-structure atomic

Lately, and by lately I mean since version 7 or so, the number of atomic expressions in Mathematica constantly grew. In former times only the native types like integers and optimised arrays were ...
5
votes
1answer
379 views

Areas of Voronoi cells from image file

I have an binary image with non-point objects. Does anyone have any suggestions how to determine area of each Voronoi cell in Voronoi diagram (goal is area distribution)? Thank you in advance.
9
votes
4answers
256 views

Pattern match for nested Association

Suppose I have Association testAssoc=Association[a->Association[1->1,2->2],b->Association[1->1,2->2]] which ...
18
votes
3answers
513 views

Dataset seems unable to handle ListDensityPlot and ListContourPlot

If I create a Dataset: ...
3
votes
0answers
97 views

Create SQL Database on a manually specified directory

I am inserting lots of data into the preinstalled SQL Database in MM: con= OpenSQLConnection["demo"] > SQLCreateTable[con, SQLTable["anyname"], SQLcolums] > ... I am running out of disk space on my ...
10
votes
3answers
332 views

Sorting Lists of lists of arbitrary length

I'm trying to sort a list of lists. The sublists are defined in length, but the length of the list containing it varies. A simplified set might be: ...

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