# All Questions

42 views

### Differences in SetDelayed (:=) in Module and DynamicModule [duplicate]

I have a question about the differences in SetDelayed assignment functions in a Module and in a ...
848 views

### detecting the radius of an incomplete circle

I need your help to detect the radius of the blue circle in images like this: . Reading these questions: 1, 2, 3, I figured that this code taken from @halirutan answer to question n°3 could help: ...
114 views

### (Symbolic) LinearSolve is slower/different after upgrading to Mathematica 9

Yesterday I upgraded from mathematica 8.0.4.0 to 9.0.1.0. Trying to run the same notebook I used many times before, it takes ages to evaluate a symbolic (linearsolve) expression which before was ...
187 views

### Simplify equations with pattern assumptions

When simplifying an expression using Simplify[expr, assumptions], the assumptions has to be explicit. Is it possible to simplify an expression with pattern ...
357 views

### Deleting quasi-duplicates from large list efficiently

I have the need to remove "duplicates" from large (>10K members) lists, where a "duplicate" is either a verbatim duplication, or the element's second entry exists as a first entry for some "earlier" ...
99 views

### Make Quantity behave reasonable with Degrees Celsius

When using a Quantity with the unit of "DegreesCelsius" multiplication doesn't work as expected. If you have 10 degrees and ...
213 views

### Generated Numbers under a constraint?

Let's say I have five four dimensional vectors $p_i^\mu=(p_i^1,p_i^2,p_i^3,p_i^4)$ with $i=1,2,3,4,5$. Now, I want to fill the entries of these vectors ($4\cdot5=20$ in total) with some numbers, but ...
147 views

### Image partition according to contours

I want to extract contours from following image or I am wondering how to partition following image: line image looks like: This question is linked: How to superimpose contour lines on ...
211 views

### Formatting an equation on a plot

I am trying to label a plot with an equation. The problem is that Mathematica formats things almost well but not exactly. The parenthesis are of the wrong size, and the powers are not high enough. ...
56 views

### Assign the Background rule in Grid (the positions can be described by a integer function)

For example, this code Grid[Transpose[Table[{n, n^2}, {n, 1, 10}]], Frame -> All, Background -> {{1 -> Red, 4 -> Red, 9 -> Red}}] produces , in ...
781 views

### Implementing a Beeswarm plot in Mathematica

I am looking for a Beeswarm plot implementation in Mathematica. Consider the following data: ...
275 views

### How to do Cases with multiple related patterns?

I would like to write a function similar to Cases, but can search for a group of related patterns together. For example, ...
177 views

### HTMLEncode a string for webMathematica

Is there a native Mathematica way to convert a string like "<select></select>" into ...
148 views

### Plotting lists, exact color values

I read some descriptions of similar problems but I cannot make them work in my example, I don't know why. I have list of 3 dim values to plot: x, ...
96 views

### Defining a function with global parameters

What I would like to do in Mathematica is something like f[x_] := a x g[a_] := NIntegrate[f[x], {x, 0, 1}] But then of course I get ...
73 views

### How to use Select to exclude a single element which I can control? [duplicate]

I have code which inserts an expression into lists that I need to remove. I can insert anything I want, a string, variable, or number, into the lists. Suppose I insert the number 13 as my blacklisted ...
165 views

### Mathematica rule to express exponentials as multiplication

I'm sorry if this has been asked before, but it is a very simple question and I would imagine it shouldn't be terribly hard for someone that knows to answer. I'm essentially trying to tell ...
94 views

### DifferentialEvolution scaling factor randomization

Using NMinimize for finding global minima, one can choose the DifferentialEvolution method. You can find a (not so) detailed ...
266 views

### How to superimpose contour lines on transformed image

My goal is to superimpose contours lines or contour plots on distance transformed image.
84 views

### Create jacobian Function from a vector Function

This is related to this question and maybe this question. I wanted a function that takes an n-parameter vector function and outputs a Jacobian matrix function, also n-parameter. I think this works: ...
122 views

### Merge two Matrices without Duplicates

I have two matrices, for example: data1 = {{"c1", "c2", "c3"}, {2, 5, 3}, {54, 2, 3}, {11, 2, 10}, {3, 5, 7}}; and ...
138 views

### Solving an identity

I am trying to solve this identity using Mathematica: $$3 \sqrt{5 \sqrt[3]{37}-16}=\sqrt[3]{a}-\sqrt[3]{b}-c$$ I know that a, ...
102 views

### New list generated from the sum of elements taken from two lists

I have been using mathematica for a while, but I have problem wrapping my head around list manipulation functions. I would appreciate any suggestions. Here is what I want to do. ListV is a list of ...
99 views

I need to integrate the function, $f(a,b)=-g(a,b)ln(g(a,b)) = -1/ Pi(( (E^(-((a^2 - E^(-t [Gamma]) [Alpha]^2)/( 1 + 2 [Sigma]^2)))) [Pi] ([Sigma]^2) )/((1 + 2 [Sigma]^2) (E^(2 ... 0answers 511 views ### Estimate parameters of the state space model I'm using Mathematica 9 and its Control Systems functionality. I've searched the references extensively but seem not to be able to find any examples of state space model parameters estimation. All ... 3answers 3k views ### Install issue: Mathematica 9 on Ubuntu 13.10 I am trying to install Mathematica 9 on a Ubuntu 13.10 system. I had this working on my previous 13.04 version but now it breaks on when trying to unpack the sh archive: ... 0answers 151 views ### Calculating derivatives of roots of equation I am interested in calculating how the roots of an equation change as one of the variables does, when the equation is evaluated numerically rather than symbolically. I have edited this code to be ... 1answer 238 views ### {Latitude, Longitude} to Transverse Mercator projection I have a shapefile with the following "CoordinateSystemInformation": ... 1answer 109 views ### Why does$Failed have attribute HoldAll?

Why does $Failed have attribute HoldAll? Are there typical situations where$Failed is ...
181 views

### Change ticks from number to hours

I have an unidimensional array (let's call it list)ranging from 0 to 86400, each one representing a second of a day (a day has 86400 secs). For example, ...
115 views

### DynamicModule with intermediate expressions

I am trying to generalize a Manipulate construct into a DynamicModule one to try and include smoother controls, but I seem to be ...
309 views

### Export an image at 1000 dpi

I'm trying to export an image at 1000 dpi. The author guide of a lot of papers wants this resolution! Then I must to import this image in Word in a small box; let's say 7x4 cm. This is the code that I ...
124 views

### Can Mathematica Operators be combined in a linear fashion for readability?

Here's a simple example. Suppose we want to find the off-diagonal matrix of m: m={{1,2},{3,4}} This can be solved fairly simply by extracting a list of the ...
382 views

### N[number, 100] does not give 100 decimal places [duplicate]

Please look at this computations: a = N[Sqrt[2], 20]; N[a^2, 100] The output is 2.0000000000000000000, which is apparently not $a^2$ to 100 decimal places. ...
82 views

### Mathematica 9 Autocomplete Pop-up issue

I've just installed Mathematica 9.0.1 Student Edition on my Laptop and my Home PC. On my Laptop, it works just fine. But on my Home PC I get this weird issue of the pop-up command autocomplete window ...
129 views

### Plotting the results of a system of equations

I believe this is a question of more list manipulation than plotting, but I hope you could help me. I solve numerically a system of equations of 3 variables, take only real solutions where one of the ...
321 views

### Remote kernel shuts down after several seconds

I have Mathematica 9 installed on two Windows Server 2008 R2 machines. Now i want to try using one of them as a frontend with local kernels and the other one for remote kernels. OpenSSH 6.5 for ...
105 views

### PlotRangePadding that's a fixed fraction of a plot's longest dimension

I am trying to produce plots of a region which can alternately become very long or very tall, and I would like to have some padding around it which is uniformly thick in both the horizontal and ...
595 views

### Morphing a “sheet of paper” into a torus

How can I visualise the standard topological "rubber-sheet" construction of a torus, that is, morphing a square into a torus? How can I start or are there any examples in the Mathematica ...
175 views

### How to customize derivative behavior via upvalues?

I'm having trouble getting customized derivatives (defined using upvalues) to behave in sane ways. By this I mean that I'd like to define a derivative using an upvalue and then have Mathematica apply ...
159 views

### Join matrix based on conditions

Given the following matrix: ...
286 views

### Error bar plot - no bars but rather point size determined by errors

Looking for a way to create an ErrorListPlot (x,y,error) with the radius of the PlotMarker ...
398 views

### Define a function with a function for an input

I want to create the functions $even[f]$ and $odd[f]$ which will apply the formula $even[f(x)] = \frac{f(x)+f(-x)}{2}$ and $odd[f(x)]=\frac{f(x)-f(-x)}{2}$ for an arbitrary $f$. I tried using ...
224 views

### Working with Java hashmaps from Mathematica

I'm using J/Link to access data from an external Java program. The data are represented as a ConcurrentHashMap (see the official specification here). ...
160 views

### String pattern matching in function definition

I have a function f and its downvalues. I want to code an extra downvalue for arguments of the form "part1:part2" I don't understand why ...
232 views

### Finding the location of the last day of the month in a list of dates

My question differs from earlier questions about getting the eom dates from a list; I want to get the position of those dates so I can get the corresponding values from other lists. My problem seems ...
121 views

### Inconsistent results for equivalent converging symbolic integrals

I have looked at previous questions and I'm aware that this seems to be a known bug: Mathematica giving inconsistent results for symbolic integrals done in different ways. The origins for the bugs ...
162 views

### Custom BoxWhisker Plot

I’d like to figure out how I can show my entire dataset overlaid on a box whisker plot. ...