0
votes
0answers
6 views
0
votes
0answers
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 ...
0
votes
1answer
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. ...
1
vote
0answers
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 ...
0
votes
0answers
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? ...
3
votes
1answer
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: ...
3
votes
0answers
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 ...
1
vote
2answers
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: ...
0
votes
0answers
9 views

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

2x² + 32 ----> 2[(x + 4)²] Is this correct?
3
votes
3answers
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}] ...
0
votes
0answers
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 ...
0
votes
0answers
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 ...
3
votes
1answer
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 ...
1
vote
1answer
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 ...
2
votes
1answer
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 ...
0
votes
1answer
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 ...
3
votes
0answers
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: ...
0
votes
0answers
31 views

Equation Simplification

Given that: ...
1
vote
2answers
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 ...
1
vote
1answer
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 ...
1
vote
0answers
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 ...
1
vote
3answers
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];); ...
0
votes
0answers
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 ...
0
votes
0answers
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 ...
1
vote
1answer
45 views
5
votes
0answers
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 ...
0
votes
2answers
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 ...
4
votes
2answers
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 ...
-1
votes
1answer
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}: ...
1
vote
0answers
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 ...
2
votes
1answer
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 ...
3
votes
3answers
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, ...
4
votes
1answer
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 ...
0
votes
0answers
36 views

Estimating a quantity

I am trying to estimate fs, sadly, I ran into some problems. Any suggestions ...
0
votes
0answers
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 ...
1
vote
1answer
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 ...
0
votes
0answers
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 ...
6
votes
1answer
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 ...
0
votes
0answers
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 ...
-1
votes
0answers
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 ...
1
vote
1answer
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 ...
1
vote
0answers
36 views

ImageAssemble and Export gif takes too much memory

Errr.... First Let's create some gifs: ...
0
votes
1answer
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) = ...
0
votes
1answer
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 ...
0
votes
1answer
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 ...
0
votes
1answer
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
2
votes
2answers
74 views

A problem with Manipulate

I have: ...
4
votes
1answer
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 ...
1
vote
2answers
87 views

How to write absolute value and square root in one equation?(runge kutta) [on hold]

I got some problem when I run my program. It hangs when I run it. This is my coding for runge kutta Geometric mean(RKGM). ...

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