# All Questions

6 views

### Generating multiple tables dependent on random variable in loop

I have the following code: ...
14 views

### Solving a chemical system using NDSolve

I have to solve a set of coupled differential equations and am not sure how to proceed. It is a model of a chemical process where I'm interested to find the species concentration as $r$ varies. For a ...
22 views

### using FindRoot to solve 3 simultaneous equations

I'm trying to solve 3 simultaneous equations derived from an electrical circuit of a common source amplifier. ...
21 views

### Solve PDE with DiracDelta function

This question is related to Solve wave equation using DSolve?. I think it is more appropriate to open another question on this topic. In the question, the compatibility conditions can be introduce ...
13 views

### How to change the atom size of LatticeData

Using the "Image" property of LatticeData, I can generate representation of lattice structures (like the first basic example did). But it seems that the atom size is a constant, can I enlarge it? ...
39 views

### Speed up derivative evaluation

I'm trying to calculate the normal vectors and the tangent vectors at the discrete points of a suface. For example: ...
27 views

### Interval Arithmetic with Symbolic Intervals

I've run into a problem with IntervalUnion and IntervalIntersection when dealing with symbolic intervals. The following code ...
55 views

### How do I partition a matrix?

I have a data file with fields x y z. When I import it to "data", I get a matrix if the form: ...
9 views

### Is this Factored out fully? (Exponents) [on hold]

2x² + 32 ----> 2[(x + 4)²] Is this correct?
44 views

### Center Graphics elements relative to one another, rather than to the full figure

Suppose I wish to generate the following figure in Mathematica: My thought was to build it in parts. First, I make the plot: p = Plot[Sin[2 Pi x], {x, 0, 3}] ...
26 views

### How can I improve the solution of my PDE?

I want to improve the last code to find a better solution for umi. For now I'm using only MaxStepFraction. Also, when I put no ...
36 views

### Plotting function $f(t)=\sum _{N=1}^{\infty } \frac{e^{-N^2 t}}{N^2}$

A function is defined as: $$f(t)=\sum _{N=1}^{\infty } \frac{e^{-N^2 t}}{N^2}$$ I wanted to plot its graph (it should be a nice contiguous function for $t\ge 0$) I hoped that Mathematica will find ...
61 views

### Does Mathematica take advantage of hyper-threading (if it is available)?

I do not know much about computer architecture, but some Intel processors have hyper-threading technology, which can apparently improve parallelization for applications that take advantage of it. In ...
30 views

### Continuation of a Problem with Manipulate

For the beginning of this discussion, see: A problem with Manipulate. Now, the final use of the Initialization command doesn't protect the Global workspace. What I am discussing is not a single ...
32 views

### Axis alignment identical to matlab plots

Mathematica uses in my opinion a weird concept of camera alignment. I would like to align the axes in Mathematica in the same way how Matlab does. For example, in the following picture you see a ...
46 views

### A question about calculus and Programming

I am a very new user and I would like to know how to calculate the following operations in Mathematica. Honestly this is not a homework. I am an french architect and I would like to be back in Math ...
31 views

### Can Mathematica poll the dimensions of the individual monitors of its host computer?

The command SystemInformation["Devices", "ScreenInformation"] returns the screen area in the monitors connected to its host computer: ...
31 views

Given that: ...
47 views

### How to force evaluation on the right of an @ operator?

Is there a way to force evaluation on the right before the Prefix operator (@) without using parentheses? I came across this question when I was working with the ...
19 views

### How can I decouple the updating of a LocatorPane's background from changes in its point variables?

I am building a Dynamic application and I'm having some trouble understanding exactly how Refresh should be implemented. The ...
32 views

### Continuous background color of adjacent cells

I'm trying to make continuous blocks of cells so that their background colors are the same, but without breaks of white space between them. E.g. After some recent digging, I found the option "Show ...
34 views

### Problem with the output of a function I program

(This is the function that I programmed) Zm2[Z_, nk_] := (zm2 = 0; For[i = 0, i < Length[Z], i++, zm2 += nk[[i]] *Z[[i]]* Z[[i]];]; Return[zm2];); ...
43 views

### Solving a system of equations using NSolve

I am trying to solve the following system of equations using NSolve, but am running into some problems. Any suggestions ? CASE1 - Facing Problem in Solving the ...
27 views

### Why does pressing up arrow key give me two spaces instead of going up?

My other three arrow keys work as they should, navigating the correct directions. The up arrow does not go up but inputs two spaces instead. How do I fix this? I am using Mathematica Home Edition ...
45 views

### Want to add a legend to 3D plot made by combining three plots with Show

I have this code: ...
65 views

### Where is f2mma.zip, Fortran to Mathematica converter?

I want to convert the SOFA libraries to Mathematica, and found out about f2mma, a Fortran to Mathematica converter. Google points to many papers about f2mma, but the only link to the software ...
41 views

### Setting up two ordinary differential equations [on hold]

Just having a total blank at the moment, I realise that maybe this question would best be suited for a math forum but i assume Mathematica is needed in order to solve these equations. So the question ...
217 views

### Why does having many Print statements slow down my code?

I have a code that I need to debug. I have put a Print[] into it that should give about 10^4 prints for table entries. I know that 10^4 is large, and this exposes ...
47 views

### Sign of a symbolic expression as a function of parameter values

I need to know the sign of the following expression for p[t] = z/(1-a), as a function of the parameters {a, b, c, z}: ...
51 views

### Extract peaks from image

EDIT: I've managed to solve the problem by using "Get Coordinates" on a couple of points and then figuring out the affine mapping by using the values they're supposed to be at, and applying that ...
128 views

### How to further accelerate arithmetic with Fermat Pseudoprime and Fibonacci number

I've been working on this all night, and I have made this go pretty fast, compared to my first iteration of the program, but now I'm out of ideas. I'm trying to write a program to test (by good ...
60 views

### How can I customize the tooltips on a ContourPlot?

I have a contour plot and I would like to have finer control over the tooltips that are displayed. For the sake of argument, suppose that I have the following plot, ...
39 views

### RandomGraph with specific constraints

I need to generate random connected simple graphs (no loops) with the constraint that exactly two vertices must only have a single edge. I can create many connected graphs (but very few will have the ...
36 views

### Estimating a quantity

I am trying to estimate fs, sadly, I ran into some problems. Any suggestions ...
33 views

### Series of square root of exponential

my problem concerns the Series command applied to Sqrt of an exponential, and it can be presented in a simplified version as ...
33 views

### How to cut imported audio?

How to cut an audio clip imported by the Import function? E.g. I'm interested in the content starting from the 100th sample up to the 200th. I'd like to avoid ...
22 views

### Want to display a animation necklace when updating a list of suggestions from an inputfield search

I have an InputField search that provides search suggestions, but I want an animation necklace to be displayed while the search is 'busy'. I would also like this to be done using Dynamic rather than ...
98 views

### How can I make Plot show the plot while it's computing it?

Normally, Plot acts like a black box and only gives you the requested plot once it has finished computing it. However it can be useful, other than interesting, to ...
53 views

### Gaussian Elimination with full pivoting

I have some problems with an implementation of the Gaussian elimination with full pivoting. It seems to me that I've programmed it correctly, but nevertheless it throws errors and I can't find my ...
40 views

### Swing of the pendulum - question update

I would like to visualize a swing of the pendulum. I want to write a function springmass[z, nzigzag], which will draw the spring (line) and the swinging weight ...
82 views

### Sow only if different than zero

I am trying to collect elements with Reap and Sow, where I am interested only in non-zero elements, that is I am trying something like that ...
36 views

### ImageAssemble and Export gif takes too much memory

Errr.... First Let's create some gifs: ...
52 views

### Hill function (equation) vs a gene

So im trying to make one equation equal another to solve for all physically realistic values of $X$. Hill function is: $$F(X)=\frac{1}{1+(\frac{X}{K})^n}$$ and Gene Z equation is:  Z(X) = ...
52 views

### Graphing a function with specified input domains

My goal is to plot the function $f(x)=x^2-2$ where $x$ is a positive rational. It seems Mathematica assumes one always wants to plot a function for real inputs (and correspondent restrictions on the ...
49 views

### What kind of algorithm can be used to map image coordinates to cylinder coordinates

I plan to flatten an images on curved surface(eg: jar or door knob) and I found a pretty good post which helps me a lot :)(link below). However, I still confuse on how to map image coordinate to ...
61 views

### Taylor series/expansion [on hold]

I want to make a second-order Taylor series expansion around point (x,y) = (1, Pi) of the function f(x,y)=x^2*Sin(xy/2) Plot inclusive
74 views

I have: ...
322 views

### Why should we make sure the calculated MD5 is of length 32?

I see when people write code on calculating MD5, (even in the documentation), they write like this: IntegerString[Hash[something, "MD5"], 16, 32] But I think ...