# All Questions

595 views

### Forecast Future Stock Prices - Brownian Motion - Again

excuse me, I think I have here a technical problem with Mathematica yesterday I posted the question with the title: Forecast Future Stock Prices - Brownian Motion I am still not very experienced but ...
139 views

### String encoding issue with Pythonika

I use Mathematica and Pythonika to run Python code inside it. And I'm not quite sure what causes my issue: all unicode Python objects look like this: ...
81 views

### Some _atomic elements' TreeForm looks confusing with Level in appearance

In[1]:= Level[1/2,{-1}] Out[1]= {1/2} TreeForm[1/2] ...
193 views

### Plot sublists as different colors

I have one big list with many sublists inside. All sublists consist of three numbers. For example: ...
53 views

### Does a manipulation of a plot area produce new data?

You do a ListPlot. Plot[Sin[x^2], {x, 0, 1}] pdat1 = With[{fig = Plot[Sin[x^2], {x, 0, 1}]}, First@Cases[fig, Line[x_] :> x, Infinity]]; You ...
184 views

### How to extend dictionary.txt

How to extend the default dictionary.txt for Dictionarylookup to all words? For example, first I ...
332 views

### ListContourPlot is blocking my geometry

I have a Navier-Stokes solution for a flow past a cylinder. I have attached the DAT file. The columns in the DAT file contain the x,y,u,v,p data, respectively. The DAT file can be obtained from our ...
697 views

From ...
282 views

### Options which require RuleDelayed

For some functions in Mathematica it is important to use RuleDelayed. One prominent example is the EvaluationMonitor for ...
3k views

### Having used Mathematica as a “gateway” language, where to from here?

I have been using Mathematica for about a year. It is the first language that I have attempted to learn. I'm still very much a newbie, but there are moments I feel more like I am waving than drowning. ...
177 views

### Is it possible to Import urls not type “”

These days I often copy urls from Internet Explorer's address bar. When I paste the url into a Mathematica cell it is neither a string nor a expression. ...
60 views

### Abridging Lists of Equations within NDSolve, Manipulate [duplicate]

I have a pretty little NDSolve function that I've finally decked out with manipulatable (by sliders) coefficients, which changes the graph in real time. However, I ...
492 views

### 3D visualization of 4D object data

I have some paired data here {{x1,y1},...{x_n,y_n}} (Download link) which represents {frequency, amplitude} of a spatial object surface mesh. Its quite a lot of cells and data as you can see in the ...
212 views

### Combine InputAlias with InputString to parse expressions from a string

My knowledge of low-level notebook programming is very limited so I would be very grateful for any input regarding the following issue: I would like to define an input alias (via ...
139 views

### Converting polygon to graph in V7

I've unsuccessfully tried many ways of converting polygon points into a graph using Mathematica 7, and I am frustrated. I looked at this post, but it doesn't work: ...
196 views

### CorrelationTest small bug?

Consider two Normally distributed random variables: x1 = RandomVariate[NormalDistribution[], {1000}]; x2 = RandomVariate[NormalDistribution[], {1000}]; I want to ...
338 views

### What kind of hypergeometric function is it?

I found a formula for an integral of a product of three Bessel functions at The Wolfram Functions Site: I cannot understand what kind of hypergeometric function it is. The Mathematica code given ...
166 views

### Exporting Specific Cells of Many Workbooks into One using Mathematica

I currently have a large number of detailed files from which I would like to extract certain cells' information to make an Archive spreadsheet. There are approximately 9 parameters of each ...
432 views

### Why is StringExpression faster than RegularExpression?

Edit: as noted by Albert Retey the performance difference is only seen when sub expression extraction is performed. If this test is used below the timings are similar: ...
214 views

### Underflow occurred in compilation

This code shown below works well for n<=10, if n>11, Mathematica gives the message CompiledFunction::cfne: Numerical error encountered; proceeding with uncompiled evaluation. >>. So ...
616 views

### How safe is the use of Block and Internal`InheritedBlock

For many questions on this site answers are given which suggest to use Block and, especially for more advanced topics, ...
118 views

### How can I say that all quantities need to be positive (and real)? [duplicate]

Can you say at the beginning of a script in Mathematica that you want all the quantities to be positive (and real)? So that in all calculations, only the real values of these quantities will be ...
229 views

When I'm tiding up my simple packages, shadow awlays comes out. Here is an example. Packages1 ...
205 views

### Emulate Powerpoint behavior: Show additional cell content with each click

Is it possible to emulate powerpoint animation behavior during a presentation with Mathematica? Considering a notebook with cell of numbered items or even several cells, is it possible to display a ...
137 views

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### Have the kernel load a user-defined function by default [duplicate]

I wrote a very simple function that I would like to act as if it were one of the default functions that came with Mathematica, so that you don't have to load or import any package before you make use ...
753 views

### Plot 3D set (or a domain of three-variable function)

is there any way to plot a "3D set" of points subject to certain rules? For example, my task is to find maximum of some function of three variables which have to meet some conditions. Of course I ...
247 views

### How to replace a variable that was assigned a value before

Question How to make the replacement $f[x] \to f[y]$ for an abitrary function $f$ if $x$ was assigned a value before? Example 1 How can I make the replacement $x +1 \to y + 1$ if I have assigned ...
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877 views

### Combine absolute and relative (scaled) coordinates

I am using Inset to add an Epilog to a plot. The position of the images (in my case: framed numbers) can be specified as an ...
1k views

### Using NonlinearModelFit to fit data with errors

Assume we have some data of measurements SeedRandom[9]; data = Table[{i,2*(1 + 5*RandomReal[])*Exp[-0.01*(1 + RandomReal[])*i]}, {i, {0, 100, 200, 400, 700}}]; ...
73 views

### How to relate memory usage with occupied positions of SparseArrays?

What is the relation of memory usage of a SparseArray and the number of its occupied positions? Let's say you build a 100.000.000 by 10 element SparseArray. And fill the two position 1/1 and ...
254 views

### Filling and Shading an Harmonic Curve

Suppose I have an equation plotted as shown: ...
84 views

### Faster way to perform SameQ[Reduce[…], Reduce[…]]

I'm have some expressions that I need to confirm the equality of. SameQ[Reduce[...], Reduce[...]] works like a charm for the more simple expressions, however when ...
120 views

### Interpolation and points of non-differentiability

I have some data, which if expressed by some elementary functions, would contain a non-differentiable point. I would like to be able to use something like interpolate to convert the data into a ...
248 views

### Optimizing functions taking matrix arguments

I'm looking for general information on how to optimize matrix valued functions, I have the following function I'm looking to maximize (or figure out if this is possible at all). ...
311 views

### How to draw a contour diagram in Mathematica?

This answer at Math.SE contains a neat contour diagram created using Mathematica: What Mathematica functions I can use to draw diagrams like this?
289 views

### Telling mathematica to output * instead of space for multiplication, so I can copy as plain text

I am trying to get some symbolic expressions in Mathematica which I would like to paste into my C/MATLAB codes. This can be accomplished nicely by selecting the expression and right-clicking to ...
244 views

### A simple StringCases problem

Given this text: text1 = " A Vitamin D Deficiency (ICD-9-CM 268.9) (ICD-9-CM 268.9) 09/11/2015 01 "; Yes, the ICD code values are duplicates- possibly but ...
230 views

### Performance of Dispatch and lists of Rules

The issue outlined here seems to be no longer present in version 10, if you use a Dispatch table! This because a Dispatch table ...
91 views

### Question about usage of Style as Dynamic object

I saw a Dynamic snippet in this answer, which wrote ...
53 views

It is possible to define function dependently to passed argument type or condition this argument fulfills (somewhat like overloading): ...
322 views

### Weird vertical line when trying to plot a histogram [duplicate]

I'm trying to plot a histogram of a few data points and overlay a plot on it (it's a fit of a geometric distribution to my data). The weird thing is that a vertical line appears always next to the ...
155 views

### How to draw tiles with different height?

I have a random matrix RandomReal[{1, 2}, {20, 20}], whose elements represent the heights of an array of tiles. The cross sections of each tile are square and ...
626 views

### Manipulating plot of random iterated function system fractal

I'm generating the Sierpinski Gasket by implementing a chaos game in mathematica. What I'd like to do is create an interactive manipulation with a slider, whereby moving it forward, plots all the ...
119 views

### FindRoot runs out of memory in Windows but not on Mac

I am using FindRoot to find solutions to a large, highly oscillatory equation which I generated using other code. When I run ...
127 views

### Filtering the elements of an array to split them into two categories

So, I am new to Mathematica, and I am trying to write something that involves taking values from one array and separating them into two different arrays. My code for doing this is: ...
108 views

### Precision of a complex number

In an output I'm getting a number like -0.33998187034939803 + 0.I. Finding ...