7
votes
2answers
175 views

Clicking phase plane with mouse

Here is what I have thus far: ...
1
vote
1answer
136 views

How to get output in a specified format

In Fortran, we can easily get the stardard and easy output format. Now, we only focus on the Integer output. See here How to realize this kind of output as formatted text file using Mathematica ? ...
11
votes
2answers
226 views

How to find out where an error occurs?

I got this error when using Mathematica: ...
1
vote
2answers
168 views

Solving for the limits of an integral

I am trying to get Mathematica to solve for the symmetric limits of an integral of a Square Wave. ...
2
votes
2answers
122 views

Only one root at specific interval

I need a help to find k here: $f(x)=-k^x + x^2$ It is not too simple. I have interest to find the single value of "k" where, inside interval {x,2,3}, the function have only one value to x when f(x) ...
2
votes
1answer
78 views

QuantityVariable usage

When I try to run the following code, Mathematica gives me an error message: "Solve was unable to determine the units of quantities that appear in the input." ...
3
votes
1answer
160 views

Export collection of plots to A4 pdf

Sometimes I want to Export a collection of plots or other Graphics to a pdf in A4 format. Right now I'm using a GraphicsGrid inside a panel which is an inset in a Graphics object. Here is an example: ...
1
vote
4answers
82 views

Delete data were y = “NS” in a list with elements {x, y} [duplicate]

I have a list of data {x, y}and not all of them have actual values. They show as {x, "NS"} or ...
9
votes
1answer
419 views

Mathematica doesn't read .mat file

Bug introduced in 6.0 and fixed in 10.2 (July 29, 2015) To be honest, I don't know if the problem is with Mathematica, or with the file; it's been generated by PicoScope, a PC-based oscilloscope ...
10
votes
6answers
637 views

Flatten nested lists

I have a list as follows lis= {a, {{{b}, {c,d,e}}, {{f}, {g,h,i}}}} which I would like to flatten to ...
0
votes
2answers
105 views

Plot Bivariate Data with Marginals

I would like to plot bivariate data along with the marginal distributions. I've arranged the plots in a GraphicsGrid as below but the marginals are centered away from the bivariate plot and I wonder ...
1
vote
1answer
94 views

Misunderstanding the difference between Map Apply (@@@) and Map (/@) [duplicate]

Here's a minimal working example of a problem I'm having: ...
3
votes
3answers
205 views

Delete rows based on specific periods

I have data (.xlsx format): two columns - data in first column imported as DateObject (dates with specific time), data in second column are numbers (113388.28, 865165.98 etc.). I want to delete the ...
-3
votes
2answers
116 views

Catch and Throw command [duplicate]

I am trying to find the time and maximum height of a projectile motion with air friction however Mathematica is "running" for a really long time and not giving an answer. Is there something wrong with ...
2
votes
0answers
91 views

Simplify large fractions

Hi i'm quite new with Mathematica and i'm experiencing some problems with Simplify and FullSimplify. I'm dealing with a sistem ...
0
votes
2answers
54 views

How do I simplify an algebraic equation with respect to a specific variable? [closed]

I have the following equation -- which is all in terms of d: ...
3
votes
1answer
83 views

NDSolve with known tolerance function

I would like to solve the differential equation: y'[x]=F[y[x],x] with y[0.5]=y0 and x ...
8
votes
2answers
314 views

Palette button with progress bar

Let's say you have a palette with a button that has to do some time-consuming task when clicked: ...
0
votes
1answer
91 views

ContourPlot color problems

I tried to use contourplot to a 2D fucntion with rescaled color, the code is given below ...
6
votes
2answers
290 views

Random walk with fixed initial and final coordinates and the length

Looking at the problem of a random walk in 2D or 3D, I would like to generate several trajectories that start all in some starting point, say, (0,0) in 2D and (0,0,0) in 3D and end up all in a ...
0
votes
1answer
63 views

NSolve taking too long to solve system of polynomial equations

I am trying to solve a system of polynomial equations (10 variables and 10 equations) using NSolve in an attempt to find all solutions. ...
0
votes
0answers
85 views

How could I add the WorldMap skin to this parametricPlot3d?

How could I stamp the worldmap inthis sphere of variable radius? I´m interested in the meridian of greenwich (longitude=length=0 Degree) is in the position of the longitude=length=0ºDegree of the ...
0
votes
2answers
205 views

Multidimensional Numeric Integration

I can't manage to calculate numerically the following multidimensional integral: ...
0
votes
1answer
46 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
192 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
257 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
412 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
78 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
438 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 ...
2
votes
0answers
63 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
106 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
455 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
231 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: ...
17
votes
1answer
430 views

Extracting road curves from an image

I have taken several gps readings while driving around town. ...
0
votes
2answers
44 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
56 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
63 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: ...
0
votes
0answers
18 views

Collecting and simplifying polynomials [duplicate]

I want simplify some expressions but also using an ordered form for a polynomial. Collect[..., Q, Simplify] should do the job, but sometimes the results does not ...
1
vote
0answers
75 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
257 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
127 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
193 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 ...
3
votes
2answers
210 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
125 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
92 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
77 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
330 views

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

I am trying ...

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