# All Questions

515 views

### Volumetric analysis from topological maps

I want to calculate the volume of fill required to level an area about the size of three foodball fields. The Department of Public Works in my city can provide me with topo data for the area. Their ...
248 views

### Is there a better way to get the eight points of intersection?

I want to get the eight points of intersection from the equations 2 Abs[x] + Abs[y] == 1 and Abs[x] + 2 Abs[y] == 1. To solve ...
307 views

### I can't get Compile to work

I've got some problems with my code, and I try to make it faster. Some of you suggested me to split my problem, and I'm here... I post the same function with and without Compile. This is a support ...
551 views

### Why doesn't FullSimplify get rid of the common factor in this expression?

FullSimplify does not get rid of the z factor in the following expression: ...
289 views

### Function that evaluates in notebook does not evaluate in CDF

I am trying to access the values of a dynamic value outside function package. Within the function package, the function is defined under the Dynamic module option. There is an error with this. I ...
230 views

### How can I eliminate equivalent equations from a list?

I want to find the numbers $a$, $b$, $c$, $d$ of the plane $ax + by +cz +d = 0$ which make the distance from the point $M(1,2,3)$ to the plane equal to 2. I tried ...
203 views

### Plot in cylindrical coordinates [duplicate]

I am trying to plot a simple vortex in cylindrical coordinates give by $v_{\phi} = \frac{\Gamma}{2 \pi r}$ Is there an alternative method to plot this than, for example, using streamplot and ...
772 views

### Strange ::usage behavior in v9

Note: This is fixed in 9.0.1. Something has gone wrong with usage in Mathematica 9. Would someone tell me how to fix it? I define a function ...
1k views

### Use Mathematica as a terminal

I love how notebooks work in Mathematica. You can edit code in real time and hit Ctrl+Shift to run it. Additionally you copy and paste different cells around to organize and test ideas. Search ...
3k views

### Summing along rows or columns of a matrix

I have a list of rows in database such as {{a,b,c}, {d,e,f},{g,h,i}} I want to be able to add each row across and each column down (like a spreadsheet). In other ...
436 views

### What's the analogue of UML in Mathematica land?

What's the analogue of Unified Modeling Language (UML) in Mathematica land? Mathematica has elements of object-orientation, but most Mathematica programs or applications aren't of object-oriented ...
788 views

### Plotting series solution to the heat equation [closed]

I am trying to plot a solution to the heat equation $u(x,t) = \sum_1^\infty \frac{8(-1)^(n+1)}{\pi^2 n^2} \sin(n \pi x) \exp(-n^2 \pi^2)$ I am using the following from another answer here on ...
661 views

### Built-in unit strings recognized by Quantity?

It’s great that Quantity can utilize Wolfram Alpha to interpret unit strings that it doesn’t recognize, but I need my code to work on machines that do not have Internet access. Is there a complete ...
203 views

### Why does $\frac{\partial}{\partial x}O\left(\left(\frac{1}{x}\right)^0\right)$ equal $O\left(\left(\frac{1}{x}\right)^0\right)$ in a series expansion?

When taking the derivative of a series expansion around a finite point, the $O(x^n)$ part is differentiated as expected. $O(x^n)$ becomes $O(x^{n-1})$ except $O(x^0)$ which stays $O(x^0)$. When ...
322 views

### how to work with list as function parameter

I want to output an arrow based on input from user and I tried writing this small function to achieve this: ...
349 views

### Is there a Break[] equivalent for short-circuiting in Table?

I am running Mathematica 7. The following is admittedly a silly example, but suppose that I have a list list whose entries are either ...
2k views

### NSolve: Mathematica 9 issue

In Mathematica 8 the following expression evaluates and returns a result in terms of InverseFunction: ...
924 views

### Finding face vertices from the face adjacency graph

I have a question about face adjacency graphs. Suppose that I have an adjacency matrix ...
240 views

### Since installing mathematica 9 I can't import certain tiffs

I have a notebook written in Mathematica 8 in which I imported Tiff images and everything worked fine. Since I installed Mathematica 9, I get the error: ...
595 views

### How can I create a fountain effect?

Inspired by this (please use Chrome or Firefox), I tried to simulate it, but I couldn't do it. I'm not familiar with Dynamic. Here is my simple code: ...
269 views

My code: ...
412 views

### More than one expression in the Table[] command?

I would like to construct a Matrix using the Table[] command. The issue is that I would like to use more than one expression for it. What I need to obtain is something like this : ...
2k views

### How to convert a hex color string to RGBColor?

For example: "#FF8000". How could I convert it to RGBColor or Hue?
207 views

### How to split a file?

Is there a way to split an external file using Mathematica? (Other than importing it, dividing it internally and exporting the parts) For instance like some File Split utility do.
361 views

### Function saved in a package won't load in the deployed CDF on startup

I wrote a function and saved it in a package. I saved a copy of the package in the Autoload folder too. I deployed a CDF that contains this function. When I open the CDF later, this function (which ...
188 views

### RSolve doesn't solve this recurrence equation

RSolve[{1 == b ((c k[t - 1]^a - k[t])/(c k[t]^a - k[t + 1])) c a k[t]^(a - 1), k[1] == b, k[3] == a}, k[t], t] I tried to read the documentation in Help ...
459 views

### DSolve output - understanding how to extract result

I'm a little confused with how to use the output from DSolve. The following works ...
1k views

### Easier program for period of Fibonacci sequence modulo p

For a little project I need to calculate the period of a Fibonacci sequence modulo p, for which p is a prime number. For example, the Fibonacci sequence modulo 19 would be: 0, 1, 1, 2, 3, 5, 8, 13, ...
719 views

### Decoupling system of differential equations

Here I have one task and it is preparation for small exam. I solved it by hand for first case 1), but I need to check it in $Mathematica$ and to try to implement it for both cases 1) and 2) ...
1k views

### Adding contour lines to a 3D plot?

I am having trouble getting contour lines on a 3D plot (ListPlot3D). I have tried ListContourPlot3D, but that gives me a really weird looking graph with a ton of dfferent levels. What I would like is ...
221 views

### Slide show - how to autorun manipulate

Is there a way to automatically run a manipulate command when you move to a slide ? I am trying to create a presentation and i have a number of slides which have use manipulate and i want these to ...
414 views

### GraphPlot only working when I evaluate twice

I have some code that builds a graph and some vertex coordinates, but when I evaluate it I get a message that the list of coordinates is not valid and the graph is not valid and it shows the output as ...
760 views

Sample data: ...
580 views

### Import Excel sheet into 3D array?

I have an excel spreadsheet that I would like to plot in a 3D graph using mathematica. The X and Y values are the location of the cell, and the Z value is the number of the scale. How can I import ...
87 views

### What options control PairedHistogram axes style?

What options control axes style in PairedHistogram? Here's the online doc. I'm trying to control axes color, thickness, and probably font size on the tick marks. but the options are confusing me: ...
274 views

### Can Button[] generate output without using Print[]?

Button[] beguiles me. A simple example follows: ...
234 views

### How to define and compute various properties of a variable size matrix

I have a rather simple question, but I have not been able to figure out how to implement a solution in Mathematica. I would like to define a variable size square matrix, say an N x N matrix A, whose ...
325 views

### How do I get the solutions of a cubic equation in trigonometric form?

I know $x^3-3 x+1=0$ has three roots that can be expressed in trigonometric form: $\{2\sin(10^\circ),\,-2\cos(20^\circ),\,2\cos(40^\circ)\}$. How can I get this result with Mathematica?
257 views

### Hyperbolic numbers and their polar form

How can I implement Hyperbolic numbers in Mathematica? How could I express their polar form? How could I calculate their power?
300 views

### Selecting terms containing some expression

Imagine I have an expression like a*k + (a^2)*b*c + b*e and I would like to obtain the term containing, for example, some power of a. In that case I would ...
530 views

### Simplistic Notation example

Notation package looks poorly documented. For example, GridBoxDividers option is not documented at all. Can someone give me a simplistic example of a Notation set ...
153 views

### What is the new command for AffineMap?

AffineMap was present in Mathematica version 4. What is the equivalent command in the current version of Mathematica?
189 views

### How to enter arrows in Notation function?

It is not clear, what symbol is used in Notation function description for arrows? How to enter it in textual mode within Workbench? Here: ...
252 views

### Efficient method for factor expressions with square roots

Inspired from this, I tried factor following expressions, Mathematica takes a long time, I couldn't even wait for it to finish. Maple calculating it takes about 5 sec. Can you recommend an efficient ...
361 views

### How can I collect data for visualization of quick sort?

I know how to implement quick sort in Mathematica. But I don't know how to get the temp data for visualization, because I used recursion. I want the effect similar to this: ...
658 views

### Why is Mathematica's expansion of expressions with square roots so slow?

Mathematica expansion of expressions with symbols isn't slow, but with square roots it is very slow. In Maple or Mupad both are fast: with square roots they both take less than a second. Here is an ...
170 views

### How does DistanceFunction work with images in ClusteringComponents?

Does anyone know the syntax to DistanceFunction? I am trying to define my own function to use with ClusteringComponents; e.g., ...
127 views

### Does the operating system matter when using Encode[]?

I have a package I want to distribute. I wrote the package in Version 9 under a Mac OS X operating system. I want to Encode[] the package. The end user will ...