All Questions

1k views

How to create symbol whose name has subscript?

I can do Symbol["foobar"] to create a symbol foobar. How to create a symbol $\theta_1$? ...
284 views

Why doesn't FindClusters find any clusters in this case?

I am trying to use FindClusters to segment data points into similar numbers but so far I couldn't get it work for this example: ...
242 views

Syntax Highlighting for Mathematica on a Blog

Every once in a while I want to paste Mathematica code on my blog. When I do, I would like it to be somewhat readable, and it would be nice to have syntax highlighting. So far all my searches have ...
441 views

How to draw a 2D curve as epilog on a 3D surface plot?

I'd like to draw Plot[Re@Sin[x+I*2], {x, -10, 10}] as an epilog on Plot3D[Re@Sin[x + I*y], {x, -10, 10}, {y, -10, 10}] and ...
630 views

Symbolic integration in the complex plane

Context While answering this question, I defined (symbolic and numerical) path integrations as follows ...
348 views

Emulating a button push or a mouse click with Mathematica code

I need to perform a long action with a button. I tried setting the DynamicEvaluationTimeout, but it seems it doesn't work for me. So I want to try using several ...
317 views

Plugging values into functions

I am very new to Mathematica, and need to know how to plug values into existing functions. For example, Math World supplies the following code for building a truth table of ...
324 views

Strange Error in Bifurcation Diagram:

I am attempting to plot the bifurcation diagram of the tent map $$f(x):=2\alpha \begin{cases} x, & 0<x<1/2\\ 1-x, &1/2<x<1, \end{cases}$$ i.e., the plot $\alpha$ vs. the limit ...
525 views

Finding residues of multi-dimensional complex functions

Say I have a function $f$ of $n$ complex variables, $\{ z_i \}_{i=1}^{i=Nc}$. And then I want to contour integrate the expression such that for each $z_i$ its an integration on an unit circle about ...
324 views

How to solve this exponential inequality?

I want to solve the exponential inequality $$8^x +18^x -2\cdot 27^x>0.$$ I tried Solve[8^x + 18^x - 2*27^x > 0, x] and ...
155 views

How to efficiently take complement of two big lists?

I have a giant list l1 and some smaller lists l21, l21, ..., ...
388 views

How do we solve N-Rooks variation using primes?

Using a $p_n$x $p_n$ matrix, how can we solve the N-Rooks problem to find a prime in every row and column? ...
167 views

How to scale the size of Pane to make it fit a Grid element?

I am wanting to make a Pane scale to fit (if Spacings are zero) a Grid element. ...
350 views

Better solution than returning a list of 3 values?

I have a function (using SetDelayed) that currently returns 3 values in a list. Later on I use the result of this list along with ...
238 views

Getting Mathematica.SE reputation data

I'm asking the following on behalf of Mr.Wizard. On StackOverflow I used the old v1.0 SO API and Mathematica to obtain user reputation data. Now we are no longer a tag on StackOverflow and the v2.1 ...
120 views

Context “Unique to This Notebook” makes variables black even if they're not defined?

I'm trying to use this technique to keep variables separated between different notebooks. It seems to be working fine, except that variables turn black as soon as they are evaluated — any ideas why ...
325 views

Numerically solving PDE with high precision

I want to numerically solve the PDE $\partial_t u(t,x)=c\partial_x u(t,x)+(mx-l)u(t,x)$ with some initial and boundary conditions and given parameters $c$, $m$ and $l$. Consider the code ...
260 views

How to convert an output to a graphic that can be selected like a plot?

EDIT: István Zachar informed me of the Rasterize[] command, which does exactly what I need. Danke! I have a self-built function that uses Grid[] to create a table that is more presentation-friendly ...
450 views

Numerical solution of a differential equation with NIntegrate coefficients

I am trying to solve a linear ODE with a variable coefficient which is given in terms of an integral I can only do numerically. That is, I have an equation of the form  ...
198 views

How can I independently move vector components (in 2D)?

Here's what may well be a simple problem that I have been having difficulty with: There are two connected vectors, v1 and v2, such that: v1 begins at the origin and and ends at point a1 v2 begins ...
77 views

What's reliable way of finding declared but undefined functions/symbols in several interrelated packages?

I have many packages some of which use some of others. I have many symbols defined in them. Is there a reliable way of finding declared/exported but undefined functions/symbols in several ...
433 views

Catching and debugging numerical errors in compiled functions

I have a compiled function (that was created using the second method of this question). Basically it's using a compiled closure. The problem is that for some parameter values it does not evaluate. ...
164 views

Import[] exception possibly caused by ToString[] behaviour which I cannot explain

Let me just start by pointing out I'm a new StackExchange user as well as a new Mathematica user (started today!) I mention this as a context to my ineptitude :) I am attempting to read through a ...
183 views

Defining a function that handles Dynamic arguments similar to Built-ins

Firstly please note that I'm using simply Dynamic behavior to illustrate my question, I'm not asking how to move a Disk or make ...
408 views

How do I plot a system with gain, first-order lag and time delay?

I want to plot the output response of a system with gain, first-order lag and time delay, where the transfer function is tf = 2 Exp[-0.1 s]/(.1 + s) To plot a ...
214 views

ParallelTable and Precision

I'm using ParallelTable[] to calculate a function over a range of my parameters , ($\omega,\ell$). This seems to be working well (in terms of speed increase) except ...
89 views

Symbolic FindInstance

I'm wondering if there is any way of doing something like the following: FindInstance[x < y, {x}, Reals] and getting, as a possible return value, ...
216 views

command to expand quaternion multiplication

Is there are any command to expand quaternion multiplication as below STEP by STEP. Below is equation from my text. I'm self learner and for some reason I can't wrap my head around quaternion ...
494 views

How can I convert x^2 to x*x?

When I try the following code: a b^2 c /. b c -> e Mathematica gives me: a b^2 c but what I want is: ...
94 views

This works: ...
871 views

Using a ListDensityPlot to map color onto a ListPlot3D graph

I have a 3 column list of data points. The first two columns correspond to x and y coordinates, with data points creating a surface in the z direction from column 3. This gives me a nice wavy ...
319 views

Enabled option for slider in Manipulate not updating dynamically

In a Manipulate expression I have a slider control which has the Enabled option ...
644 views

Plot showing discontinuity where it shouldn't

I was trying to integrate a continuous function with a kink and I did it two ways and both ways the plot of the result shows a discontinuity. I also later want to differentiate the Integrated ...
225 views

Realtime audio processing using Dynamic

Can I make real time audio processing with Mathematica in the same way I can do with images using Dynamic[CurrentImage[]]. I know that is possible to use ...
342 views

Can an Interpolation function be 'saved'? [duplicate]

Possible Duplicate: Save interpolated function I am importing tables with sizes of 100k - 500k rows and 4 columns. The larger the table, the slower my Mathematica runs for all computations ...
903 views

How to export data from excel specific cells into mathematica?

How to export data from excel specific cells into Mathematica? Given that the spreadsheet tab is named XYZ and that I have several cells at various locations in the same column in Excel that I want to ...
152 views

Logical operations on a list [duplicate]

Possible Duplicate: Applying And to lists of Booleans I have two lists filled with logicals: ...
273 views

Small Issue with Chebyshev Derivative Appoximation

I am trying to get approximate the derivative of a function from its Chebyshev expansion. I start out with the following random function ...
224 views

Return a Part by Reference? (For accessing hierarchical / structured data)

Is there a way to return a part of a list by reference, for reading and writing? I want to do this so I can easily manipulate "rule-styled structured", i.e., hierarchical data that is loaded from a ...
714 views

How does one draw a parallelepiped in Mathematica?

I'm a bit new to the application, and I'm not sure how to draw a parallelepiped in Mathematica.
374 views

What's fastest way of defining 10^5 down values?

I want to define isGood[___] = False; isGood[#] = True & /@ list where list is a list of several million integers. ...
243 views

About high dimensional integrals

I want to be able to do high dimensional integrals like, (..naively I wrote it as this..) ...
157 views

Comparing Unequal Lists of Surnames to Establish Over or Under-Representation

I've been using Mathematica to explore historical records. I have two long lists (one is 69k, the second 17k) of unequal length. They are like so (FWIW, the first list is the first 40 entries from the ...
337 views

Generate a Combination of letters by a number

I'm trying to write a function f. example: ...
221 views

Can mathematica simplify an expression setting simplified answer equal to zero?

Basically I want to reduce something like: Subscript[P, 4] - Subscript[P, 5] == Subscript[R, 4, 5]* Subscript[i, 4, 5] when only one of them is known (...
226 views

Creating a matrix from the output of a variable inside a for loop

I would like to enter the results of the following loop inside a matrix as its elements: ...
669 views

Is Abs[z]^2 a bad way to calculate the square modulus of z?

For a numerical quantity z, Abs[z] returns the square root of the sum of the squares of the real and imaginary parts of ...
211 views

Debugging graphics

All the examples I am seeing on internet are related to normal functions that carry out loops and assignments but I have not seen one example where I can see a graphics based program being debugged. ...