0
votes
1answer
53 views

Selecting from a list [duplicate]

OK, I know this must be a simple problem, but right now I'm just stuck and need some advice with this :). I have the following list: ...
2
votes
2answers
198 views

Strange result of an infinite sum

I have the following definition: o[a_] := Sum[ x^(2 k + 1) Product[(2 i + 1)^2 - a^2, {i, 0, k - 1}]/((2 k + 1)!), {k, 0, Infinity}] Now when I evaluate <...
0
votes
1answer
311 views

NdSolve problem :NDSolve::ndode: Input is not an ordinary differential equation

I am new to Mathematica. I am working on solving the following different equations numerically written in the code as below. Not so sure about the boundary values that depends on R (M(0)=0, n(1)=0) ...
4
votes
4answers
548 views

How can I draw a square root spiral? [duplicate]

I found this picture on the net. How can I reproduce it in Mathematica?
1
vote
1answer
88 views

How to reset the “front end” to a 200% default

I wish that when Mathematica is run the "front end" this default to 200%, and perhaps other things where you can not change, as there are directly in the menu. Thank You
2
votes
1answer
552 views

(NDSolve) Non-linear 2nd order ODE, regular singular point (looking for good methods for this problem)

I am solving this set of non-linear 2nd order ODE by NDSolve, $$r^2\frac{d^2f}{dr^2} = 2f(1-f)(1-2f)+\frac{r^2}{4}h^2(f-1)$$ $$\frac{d}{dr}\left[r^2\frac{dh}{dr} \right]=2h(1-f)^2+\lambda r^2(h^2-1)h$$...
2
votes
0answers
70 views

Enforcing WorkingPrecision in NIntegrate

I have a very complicated 2D integral that I need to calculate repeatedly, and I'm trying to speed it up a bit, since at the moment it's taking a couple of days to complete. One thing I've noticed is ...
-1
votes
1answer
113 views

Visualize Space Pascal's triangle

Visualize Space Pascal's triangle I found this image on the web, I want to know how to draw with software. I try to search, found this. I have learned a mapping in the plane
-1
votes
1answer
41 views

Different output, simple question [closed]

I found a slightly different output than what was expected in a book. DefSumMod[10] G={0,1,2,3,4,5,6,7,8,9} CircleGraph[G,Add[1]] Why is the tracing directed ...
2
votes
1answer
785 views

Nullclines and equilibrium point labels

I am trying to draw the vector field, nullclines, and equilibrium points for the system $$ \begin{align*} x'&=2x-y+3(x^2-y^2)+2xy\\ y'&=x-3y-3(x^2-y^2)+3xy \end{align*} $$ I have completed ...
5
votes
3answers
281 views

Converting between AbsoluteTime and Unix time

By trial and error, I've found that the following gives the current Unix time: AbsoluteTime[] - UPOCH where UPOCH can be defined in any of the following ways: <...
18
votes
1answer
488 views

Extracting road curves from an image

I have taken several gps readings while driving around town. ...
0
votes
2answers
49 views

How do I complete this function len for the length of a line segment?

I need to have len[{{x1,y1},{x2,y2}}] is Sqrt[(x2-x1)^2+(y2-y1)^2]. The beginning of the function will be defined as ...
0
votes
1answer
61 views

return multiple properties of financialdata

Sorry, very silly newbie question.. regarding FinancialData, how to return multiple specified properties. eg. if I want Open & Close properties , or perform an operation such as Open-Close ...
1
vote
1answer
68 views

Implicit region is not “valid” in ParamatricNDSolveValue function?

I am trying to solve a geometric problem with relation to my Schrodinger equation and its boundaries. Here is my code: ...
1
vote
0answers
90 views

Better control of vertex positions in GraphPlot?

I am trying to graphically visualize a sort of a transformation network. My program generates a list of vertices and edges and I want to turn that into a visually clear graph fulfilling a few ...
-3
votes
2answers
296 views

Solving the symbolic quadratic equation ax2 + bx + c = 0 [closed]

I need to ask Mathematica to solve the symbolic quadratic equation ax2 + bx + c = 0. Does it give you the right answer?
2
votes
1answer
155 views

Surface Plot 3D of a strongly concave shape

I have a list of {x,y,z} points that all lie on the surface of an object (model output from COMSOL). I would like to generate a graphics object that reproduces the surface. Ideally, I would like ...
2
votes
1answer
213 views

Is there a bug in MatrixExp in Mathematica v10?

I'm trying to compute MatrixExp[-I t {{0, 1/2, 0, 0, 1/2}, {1/2, 0, 1/2, 0, 0}, {0, 1/2, 0, 1/2, 0}, {0, 0, 1/2, 0, 1/2}, {1/2, 0, 0, 1/2, 0}}] With ver 9 the ...
4
votes
2answers
240 views

Dynamic arrays and lists with compile (Append, Linked lists etc.)

I have a code that I need to compile. The code contains a loop in which I need to gather data into a list. The question is how to best gather data so that the code works inside Compile. The following ...
0
votes
0answers
47 views

Having trouble reading this output (pure functions) [duplicate]

I'm after decoupling some odes and trying to solve them using mathematica but my output is in terms of Functions and InverseFuntions and I'm afraid I have no idea how to translate the output into ...
2
votes
1answer
131 views

How to add a static JPEG into a Manipulate without slowing it down

I´m trying to add an image from a book into a Manipulate but it makes the Manipulate update very, very slowly. So much so that ...
2
votes
2answers
123 views

Problem with the BarChart3D function

I have a list of values {x,y,z} and I would like to create a 3D bar chart with axis x,y,z . ...
1
vote
1answer
83 views

The relative motion of the points about the common center of mass

There are 2 points with masses m1 and m2, their common center of mass   rC,r1 and r2 their radius vectors, r=Abs[r1-r2]. I built a trajectory of both material points, as well as their common center of ...
-1
votes
1answer
544 views

How do I get axes labels in a DensityPlot? [duplicate]

I am trying ...
1
vote
1answer
120 views

FunctionDomain doesn't work with If

When I call FunctionDomain for function defined by a formula with If, for example ...
3
votes
1answer
170 views

How to accelerate my code?

Given a 2D $M \times N$ matrix with non-negative values, I would like to find a path going from top to bottom such that the sum of the path is minimum. My function is defined as follow: ...
3
votes
1answer
429 views

Weierstrass function

I am trying to create plot of the Weierstrass function in Mathematica. I wonder if it's possible, when I define this function as ...
5
votes
1answer
186 views

How to use DSolve with vectors without decomposing into vector components?

Given a basic, two-dimensional ballistic trajectory problem, I can solve the equations of motion using DSolve (or NDSolve) by ...
0
votes
0answers
75 views

Are there any instruction(Mathematica-native) to draw an Arc in 3D? [duplicate]

I want to draw an arc in 3D. I viewed circles,ellipses and arcs in 2D with Circle[...] but when I want to draw and arc in 3D I can´t find any instruction for taht purpose. The question is: Are there ...
7
votes
2answers
313 views

How to make a binary function associative? (Or define an n-ary function?)

Suppose I have a simple function that I assign to an operator f[a_, b_] := a + b CirclePlus = f Then I want to write ...
3
votes
1answer
192 views

Is there a plot style for PolarPlot to look like matlab polar()?

The plot style of Matlab's polar function appears to be pretty conventional for antenna radiation patterns in the references I'm looking at (sometimes with tick markings that count +- from the ...
-1
votes
2answers
151 views

Projectile motion with air friction

I need to find the x and y components of a projectile's position, its velocity at any evaluation point, time of flight, range, and maximum height. I have already made the code for a projectile ...
-1
votes
1answer
232 views
2
votes
1answer
368 views

Row echelon form question

I am wondering if there is a Mathematica command that will put a matrix in row echelon form. That is, put $$ \begin{bmatrix} 1 & 2 & 3\\ 2 & 3 & 4\\ -1 & 0 & 2 \end{bmatrix} $$...
1
vote
0answers
77 views

How to simplify an expression with a radical sign nesting in a radical sign

Is there a function can simplify an expression with a radical sign nesting in a radical sign in Mathematica? I use V9. RatDenmon is a function that can ...
1
vote
2answers
126 views

Random walk using Module [closed]

I want to create a random walk using Module. The walk start at {0, 0}. At every step, x ...
0
votes
1answer
38 views

Getting nicer values for eigensystems [closed]

I want to find the eigensystem of the matrix {{0.9, 0.5}, {0.1, 0.5}}. I tried Eigensystem[{{0.9, 0.5}, {0.1, 0.5}}] The ...
2
votes
2answers
132 views

How can I create a shortcut for a command in Mathematica?

I am using mathematica to write my physics homework, one thing that trouble me is that I need to enter lots of vectors. I usually type the name of the vector, "A" for example, and then hit "[Ctrl] 7" ...
0
votes
2answers
128 views

Block anti-diagonalize a square matrix?

In Mathematica there is a very convenient function called JordanDecomposition[]. It takes a square matrix A as an argument and ...
1
vote
1answer
113 views

Draw two curves and a surface

I'm trying to draw two curves and a surface, where one of the curves is to appear on the surface. Unfortunately the curves are drawn with very few points and appear extremely unclear. Is there a way ...
3
votes
1answer
61 views

Sort Unicode characters

Sorting ASCII phrases works fine: Sort[{"albatrob", "abo", "dict", "star", "mangel", "m"}] (*{"abo", "albatrob", "dict", "m", "mangel", "star"}*) But unless I'm ...
0
votes
2answers
520 views

Projectile motion in Mathematica using Euler's method [duplicate]

I need to write the equations of a ball in projectile motion (ignoring air friction) with an initial velocity of 40 m/s at an angle of 40° with respect to the horizontal. Specifically, I need to write:...
6
votes
2answers
213 views

Is there a way to detach/reattach the Frontend from a running Mathematica Kernel?

I perform long calculations on a fast remote machine running the Mathematica kernel, where I followed the very useful guide Remote Kernel Strategies to establish the connection. I wonder, however, if ...
0
votes
1answer
44 views

Writing a math formula to order results in a certain way [closed]

I am not very well educated in math and I have a math puzzle that I'm trying to solve. I have the following list and each object has 3 numbers. The first 2 numbers are better when they are as high as ...
6
votes
6answers
541 views

Find (longest) overlapping elements between two lists

I am trying to write a function f that returns the overlapped sublist where A ends with this sublist while ...
8
votes
0answers
122 views

TimeConstrained[Delete[Range[1],1]] causes kernel crash

Run these two samples of code here (AFTER SAVING YOUR CURRENT WORK): Do[ TimeConstrained[ While[True, Delete[{1}, 1]; ];, 0.1];, {100}] ...
2
votes
1answer
206 views

Polar color coding for complex function plots?

Having browsed this Q on plotting complex functions and the Zeta page, I don't see anything as nice as this plot from Matilde Marcolli's slides "Geometry and physics of numbers". Looks like ...
0
votes
1answer
88 views

Weird subscript name in output [duplicate]

One of my first times using mathematica, I'm getting a weird Subscript(1,0) output when I try to solve a derivative. What is going on and how can I fix this?

15 30 50 per page