# All Questions

742 views

### ParametricPlot3D with three variables

ParametricPlot3D can be used with one or two variables to plot paths and surfaces in 3-D such as ...
273 views

### How can I produce a branch cut in a surface plot based made with ListPlot3D?

I need to create some surface plots, based on a function that is computationally expensive (a few minutes per point). The function has some branch cuts. The command ...
435 views

### Intersection of two splines

I have a collection of sets of points, each set defining the segment of a (nice) curve on the unit sphere $S^2 \subset \mathbb{R}^3$. The points are computed numerically. I now want to compute the ...
106 views

### Document settings for online viewing

I'm trying to figure out how to prepare a notebook for NICE online viewing when it's been converted to PDF form. The students I am working with (sadly!) will not be able to use the CDFPlayer to view ...
316 views

### How to delete all rows in datafile that contain a string

I'm importing some data from a file. However, the file was created by an unreliable instrument, such that the data looks like this: ...
103 views

### Solve failing and not clear why

I define the function: w[q_, n_, a_] := q/(4 Pi n r^2) (1 - Exp[-2 r/a] (2 (r/a)^2 + 2 (r/a) + 1)) I then want to solve: ...
108 views

### Problem in exporting a plot with background to pdf

Just wondering if someone could help me for this problem. I have utilised prolog to use a jpg image as the background of my plot in order to compare my results with ...
181 views

### Incorrect numerical derivative of function that uses FindRoot

I am trying to plot the derivative of function g[x] below where g[x] is defined as the root of another equation. However, I am ...
481 views

### Problem with convert matlab function into mathematica version of euler angle

I've wrote a function that will extract euler angle from matrix according to Matlab's function in AeroSpace toolbox's dcm2angle package file. But not quite right. ...
234 views

### Why does Mathematica not seem to know that $i^x$ cannot be equal to $0$?

I am experiencing a curious behaviour of Simplify when handling expressions involving powers of $\mathbf{i}$, such as $\mathbf{i}^x$ where $x$ is unknown. For ...
364 views

### Ugly font rendering (ubuntu 12, overrides system settings)

Mathematica 9 on Ubuntu 12 renders fonts very poorly. Text is readable, but it makes it very hard to concentrate on programming. Since smoothing on Ubuntu on low DPI screens isn't very good either, ...
85 views

### How can I programmatically remove tagged cells without scrolling to them?

I've learned a rather succinct way to delete tagged cells using NotebookLocate, but I would prefer the notebook did not scroll to the selection just for a delete ...
236 views

### Importing numerical data from RTF file

This might be a very simple question but I have been struggling with it for a couple of hours, so thought maybe someone here can show me a quick way of solving it. I have a file in rtf format ...
241 views

### Manipulate with variable number of sliders plus variable number of functions

I'm trying to setup a Manipulate where I have a variable number of sliders similar to this one, where every slider controls a function. In my case, there will be an additional slider which sets the ...
102 views

### Truncate a fractional value to particular number of bits?

If I have a fractional value, how can I truncate (not round) that to a certain number of bits, like 8? For example, for Pi 3.141569265359... the fractional part is 0.141569265359... ...
223 views

### How could I improve this Central Limit Theorem demonstration speed- and content-wise?

My purpose is to demonstrate the Central Limit theorem by assuming two custom distributions, taking some random samples, calculating their means and ploting the results. Ideally, the histograms should ...
1k views

### What is an “INTERNAL SELF-TEST ERROR”?

I got this all the time after updating to 9.0 (OS 10.8.2): That's Clipboard|c|3015 for the benefit of anyone searching. The error went away with 9.0.1, but a version has reappeared (multiple times ...
97 views

### How to get different items in a list to interact to get a result?

I have two lists, for example (the real lists are much longer): list1 = {1, 2, 3, 4, 5, 6, 7}; list2 = {9, 10, 11, 12, 13, 14, 15}; I want to create a single ...
211 views

I have a lot of 32-bit numbers in hexadecimal symbolized as they are in C (for example, 0x1230abde). How can easily read these in Mathematica?
547 views

### Hex Representation in Mathematica and Python

I want to convert a code from Mathematica to Python. I am using the following code to convert a code to hexadecimal, binary and so on: ...
5k views

### How does one set a logarithmic scale in a ContourPlot?

How does one set a logarithmic scale for both x and y axes in ContourPlot in Mathematica?
152 views

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126 views

### Non-convergance of the solution of the 1+1 partial differential equation

I am stacked with a partial differential equation as follows: This is the $\LaTeX$ expression for the equation  \frac{\partial y}{\partial t}=\frac{\partial^2 y(x,t)}{\partial x^2} ...
649 views

### Find parameters of ODEs to fit solution data

Problem How to find the initial conditions x[0],y[0] and the optimal value of parameters ...
229 views

### How can I expand a inequality with Abs

I want Abs[x] + Abs[y] <= 1 to be convert to ...
111 views

### How to make InverseFunction work on function defined with restriction on arguments

This example works to define InverseFunction on the first argument of a function ...
66 views

### kernel shuts down during listplot [duplicate]

In at least the following situations, I have experienced that the kernel has shut down during evaluation. The thing is that there is no message at all when it shuts down. ...
603 views

### I want to calculate the pixel values of an image and export to a standard format

After finishing a few tutorials, I thought I was ready to calculate the pixel values of a large (smaller numbers 20x20 used here) image and export to a standard format (.jpg) but my code doesn't work. ...
972 views

### How to partition a list of numbers in two lists of numbers such that each lists elements sums up to the same number?

I have the following list of squares. {1, 4, 9, 16, 25, 36, 49, 64, 81, 100, 121, 144, 169, 196, 225, 256} Their sum is $1496$, I want to make two partitions ...
1k views

### How to render a 3D ellipsoid with Graphics3D?

With Graphics3D[Sphere[{0,0,0},1]] I can render a uniform 3D sphere, but how can I render an ellipsoid? I would need to specify the rotation of the ellipsoid and ...
82 views

### Issues FindRootPlot command

I've had some fun playing around with FindRootPlot for a simple system of equations: ...
1k views

### Nice formatting for the results of a dice game simulation

One of my Mathematica interests is in problems related to the formatting of output. Getting nice formatting from Mathematica is often frustrating, but occasionally Mathematica will delight me by ...
380 views

### How to find Image Size of a control object?

I want to find the ImageSize or at least dimensions of any control object irrespective of it being an image or an any other control such as ...
85 views

### creating some smooth density functions

I would like to create some density functions based on some distance measure $D$. As a base density function lets say I have a Gaussian density $f$ with mean $-1$ and variance $1$. I would like to ...
121 views

### Bound on number of function evalulations in FindMinimum

I am minimizing a nonlinear constrained problem using FindMinimum. The problem involves about 200 variables and the function is a black-box which cannot be ...
173 views

### Writing NDSolve-like functions

I've been using Mathematica for a while now, and there are multiple common tasks that I end up doing. I'd like to learn how to convert them into functions so that I can store them in some file and ...
432 views

### Animation is jerky, but slider is not

When I do the following simple animation (from the book Mathematica Navigator, p. 316) the slider control changes the image smoothly, but when I play the animation it is jerky. Is there anything that ...
118 views

### Esc-esc for special characters and autocomplete in Mathematica 9 [duplicate]

I recently upgraded to Mathematica 9 and have noticed a slightly annoying behavior that I was looking to remedy. In the past I would type special characters, e.g. ...
119 views

### Why DateDifference returns machine number?

Is there any specific reason why DateDifference cannot give an exact number in this case? ...
2k views

### How to do the log scale plot for ListContourPlot

My current code is: ...
389 views

### Display a number in Mathematica 9 in periodic form

I want to display a rational number in Mathematica in periodic style. PeriodicForm isn't working anymore. It worked in Mathematica 5 and now I'm using Mathematica ...
81 views

### Cell copy results in jaggy, aliased output

When I copy a cells by selecting them from the collapse bars on the right, then using the context menu option "Copy", the pasted image of plots is not anti-aliased and in general the text seems to ...
238 views

### Iteration process involving several functions

I would like to carry out a following iteration process: Apply function f1[a_,b_,c_,d_] to a starting list l1={a1,b1,c1,d1}, ...
427 views

### How can I make a cell that contains an image which can be shifted?

When you're looking at some help pages, they may have cells containing images which can be shifted within the cell by left-clicking and dragging the mouse. Here is a sample: ...
117 views

### Function to differentiate between date pattern and specific string format

I'd like to write a function that behaves one way when the argument is a Mathematica date, such as {2013,12,15}, or with added hours, minutes and seconds if ...
117 views

### Frontend coloring of Table[x, {x, 0, x}]

I have a small question about how the Mathematica frontend colours in the variables that appear in (wrongly written) iterators. More specifically, I'm intrigued by the colour of the third ...
355 views

### How do I label contour lines that are superimposed on a 3d plot?

I need to generate a 3D plot of a function, say $z = \sin(x)\cos(y)$, with contour lines drawn at specified intervals. I also want to label each contour line with its $z$-value. I have discovered how ...
213 views

### How to create a SparseArray satisfying multiple conditions on Parts and Elements of a Matrix?

I have a matrix m1 of size $3 \times 19$. Rows $1$, $2$ and $3$ represent $3$ different groups, and columns represent $4$ different blocks: block1 - columns $1$, ...
I need to create a list that as an input receives the number $N$ of elements that it will contain and that returns: ...