# All Questions

207 views

### How to make a point's position time-dependent given a formula for the next step?

I've made a program that is just some points on a plane. Red points are cops and green points are robbers. Each point has a vector indicating where it is going to be in the next step of $t$. Right now ...
184 views

### How to join held Lists?

Let's say I have a = Hold@{2+2} b = Hold@{4+4} How can I get Hold@{2+2,4+4} ie join the two held lists ? More ...
237 views

### Programatically adding/retaining comments within a nested list

Is it possible to convert the following list of strings to computable numbers with the comments preserved? ...
1k views

### How do I simplify a vector expression?

I am doing vector analysis. I have figured out that the following expression won't be simplified in Mathematica: Simplify[Dot[x, y] - Dot[y, x]] I think the ...
379 views

### How can I find the vertexes of a Polygon?

I made a polygon with the following vertexes : ...
282 views

### how to read in a file in the same directory?

Now I am writing a small package. I have written several files and put them in the same directory. And some files need to read in or include another file in the same directory. But when I simply write ...
182 views

### Prevent interdependence of controls

My question is probably best illustrated with this small sample code: ...
298 views

### How to create a multi-selectable setterbar with colored buttons

Background: consider the following code-snippet. ...
298 views

### Why can't D[] be used in place here? [duplicate]

Possible Duplicate: General::ivar is not a valid variable when plotting - what actually causes this and how to avoid it? Beginner question: Why can't I use ...
2k views

### Notation of partial derivative

I want to write partial derivatives of functions with many arguments. Why is it that when I type f[x,y] ctrl+6 (0,1) it turns out to be bad syntax? The output of ...
582 views

### Entering block matrices for an arbitrary matrix size

Background: How to enter matrices in block matrix format? and the following: I want to create $$f(A,t) = \left [ \begin{matrix} A & t \\ 0 & 1 \end{matrix} \right ]$$ where $A$ ...
254 views

### Revert FullForm-ed text to prettyprinted

Sometimes strings in a notebook/package file end up garbled due to some unknown/unintentional conversion of the expression/cell/notebook. I could not find a way to revert such unreadable text to its ...
697 views

### Why don't * and ^ work as I expected on matrices?

For example, this input... {{1, 2}, {3, 4}}*{{1, 2}, {3, 4}} produces this output... {{1, 4}, {9, 16}} and this input... ...
559 views

### Finding differences between Pi with varying number of decimals

I have the following code In[32]:= N[Pi, 2] Out[32]= 3.1 In[33]:= N[Pi, 1] Out[33]= 3. In[34]:= N[Pi, 2] - N[Pi, 1] Out[34]= 0.*10^-1 Why can't Mathematica ...
244 views

### Manipulating a sublist based on position

I have a huge list with huge sublists of the form list={{a,b,c,d},{e,f,g,h},{i,j,k,l}} I am looking for a way to manipulate these sublists based on the positions ...
216 views

### How can I scale a plot in vector graphic or PDF form?

I am not at all a computer graphics expert, but it seems that portable document format (PDF) files have a "native size," even though they may (and usually do!) contain vector graphics that can be ...
133 views

### Evaluate Initialization Cells of another notebook

Although there may be better ways to get data and definitions from another notebook (packages, read/write dumps, ...), sometimes it is convenient to just evaluate the initialization cells from another ...
261 views

### AxesLabel in Histogram3D unreadable

I'd like to modify this chart to relocate the z axis label so it's not over printing the values. ...
755 views

### How to simplify a complicated Sum in terms of power Sums?

For example, I have: $a=\sum _{r=1}^n x_r \left(\left(\sum _{i=1}^n x_i-x_r\right){}^2-\sum _{i=1}^n x_i^2\right)$ ...
694 views

### Ways to compute inner products of tensors

One way to evaluate the following sums is combining Table and Sum: $u_{abcd} = \sum_{e=1}^3 v_{aeb}w_{ced}$ $q_{ab} = \sum_{d,e=1}^3 v_{d e a}w_{deb}$ It will look like ...
254 views

### Is it possible to induce Mathematica to chop off parts of Graphics objects that exist outside of a Frame?

I am running Mathematica 7. In a Graphics environment I am setting Frame -> True (and using ...
893 views

### Spreading colors in ListDensityPlot

I want to create a two-dimensional plot using data from an external file. This file contains several triplets of numbers. The first two columns indicate the x and y position, while the third one works ...
650 views

### How to expand a function into a power series with negative powers?

Is there any way to expand this expression a+b(1-Exp[-T/(b c)]/(z-Exp[-T/ (b c)]) (where a, ...
1k views

### Is there an option to change the space/distance between tick labels and axes labels for plots?

In an attempt to squeeze more plots and controls into the limited space for a demo UI, I am trying to remove any extra white spaces I see. I am not sure what options to use to reduce the amount of ...
993 views

### How to mark visible points on a Plot3D?

I'd like to illustrate a two-variable function discontinuous at zero. The function is $f(x,y)=xy/(x^2+y^2)$ unless $x=y=0$, in which case $f(0,0)=0$. I thought that I could draw a plot and then mark ...
288 views

### Why does Manipulate execute the expression twice?

When I execute Foobar[] in the code below and move a slider, the variable grad is printed twice. Why is this? How can I make the ...
347 views

### Want Interactive PlotRange of Graphics[{}]

I am trying to do: ...
277 views

### Is it possible to insert arguments into functions when they're used like Function@ or //Function?

Is it possible to insert arguments into functions when they're used like Function@ or //Function? Sometimes I need to do this, but then I have to return to the standard function usage: Function[] ...
1k views

### Formatting Ticks and FrameTicks labels with a function

Is there a convenient way to format tick labels? In this example I would like to use the default Mathematica tick intervals, but simply convert the X axis labels to strings with "s" added. As you ...
189 views

### LocatorPane, selecting multiple Locators

Consider the following snippet ...
135 views

### How to let output and message be print to two separate external files?

How to let output and message be print to two separate external files? Also, I'd like the content print out to have similar look as when it's print inside the notebook, i.e. it should be in ...
2k views

### Animate ParametricPlot3D for two different parametric equations

I want to write a computer program to generate 3-D plots (with x-y-t axes) to demonstrate the evolution of the two missiles in the following case: i. $x = 100t$, $y = 80t-16t^2$ for $0\leq t\leq 5$ ...
684 views

### How to make a dynamic stopwatch?

For some experiments I need some basic timer function. I tried various methods, and neither of them are fully satisfactory. What I need is a button, that starts/stops a timer, resets timer with each ...
155 views

### Why does the order of arguments in Show influence the result?

I am wondering why there is a difference in the results from evaluating the two expressions, which differ only in the order of the arguments given to Show. When I ...
241 views

### Understanding Villegas-Gayley

Temporary message: I have written another question about the behaviour the code by Oleksandr R. . Sadly I clicked "discard" and that was lost. I am a bit demotivated now and in order to not let the ...
273 views

### How to combine elements of two matrices?

Given two matrices m1 and m2, e.g.: m1 = {{a1, b1}, {c1, d1}} m2 = {{a2, b2}, {c2, d2}} How can one obtain the following? ...
655 views

### How to speed up the plot of NIntegrate?

Here is a toy example: f[t_] := NIntegrate[Sin[x], {x, 0, t}]; Plot[f[t], {t, 0, 10}] // Timing Even such a simple example will take 2.8 seconds on my computer. ...
654 views

### Defining a function that completes the square given a quadratic polynomial expression

How can I write a function that would complete the square in a quadratic polynomial expression such that, for example, CompleteTheSquare[5 x^2 + 27 x - 5, x] ...
310 views

### Variant of the cutting-stock problem in Mathematica

I'm pretty new to Mathematica and am trying to learn to solve problems in a functional way. The problem I was solving was to list the ways in which I could sum elements from a list (with repetitions), ...
565 views

### Why does Plot leave gaps in the graph of a continuous function? [duplicate]

I have plotted the overlapping area of the UnitBox and the triangle function as: ...
251 views

### Manipulate flickering and consuming lots of CPU

I am new to Mathematica and was experimenting with a simply problem of plotting a tangent to a curve and being able to move the point at which the tangent is drawn using ...
334 views

### Label both sides in BarChart

I have labeled the name(A,B,C) of each row on the left and value of each item , is there any way to put the total number(6,7,5) of each row on the right side without changing other labels? ...
268 views

### How do I get the equivalent of the $\LaTeX$ \tag{} in Mathematica?

How do I get the equivalent of the $\LaTeX$ \tag{} in Mathematica? $a+b=x \tag{1}$ I'm not necessarily asking how to use the $\LaTeX$ \tag{} itself in ...
165 views

The following doesn't appear to work: DynamicModule[{}, Button["Press Me", ChoiceDialog["OK or Cancel?"]]] When I press the button labelled "Press Me", a dialog ...
643 views

### Failed to connect remote Mathematica kernel using J/Link

I'm trying to connect to a remote Mathematica 8 kernel (on a Windows machine) using J/Link. On the client machine, I put the JLinkNativeLibrary.dll file in ...
960 views

### Combine multiple PDF files into one document

I have multiple single page PDFs I'd like to join together into a single file. (Obviously I mean the file format and not the probability distributions here!) I'm aware of free online services such as ...
204 views

### Scope within Context

To define some package-wide functions/variables, what approach is recommended? I tried to use contexts with the Begin function, but this failed: ...
352 views

### Cropped pdf file after export

I have plot generated by Plot[] function that I want to export to pdf file. The problem is that Export[] function somehow cuts a ...
222 views

### HoldFirst and inserting additional options into a Grid of Graphics

This is related to my earlier question, but is specific to an issue I have encountered with the use of the HoldFirst First, let's create some fake data for ...
3k views

### How to get rid of warnings when using Solve on an equation with inexact coefficients?

When I solve this equation in Mathematica 8, I can get the right answer, but with some uncomfortable warnings. Equation: ...

15 30 50 per page