2,568 reputation
214
bio website mathani.tumblr.com
location
age
visits member for 1 year, 6 months
seen Sep 8 at 9:14

honeycomb decay

Mathematica can save time delays between frames together with animated GIF (look for "DisplayDurations" under options of GIF format). This in turn allowed me to produce exactly 28 frames for the decay of this honeycomb with 28 cells. Modelling radioactive decay, where for example time intervals between clicks on a Geiger counter are approximately exponentially distributed, I can simulate the delays (rounded and shifted to run from t1/100-th seconds with average value (t1+t0)/100-th seconds) as:

delays[{t1_, t0_}, n_] :=
 t1 + Round[
   RandomVariate[ExponentialDistribution[1/t0], n]]

I set t1=2 here. Most browser can't present a delay of 2/100-th seconds properly. Chrome can.


Sep
8
comment Solve equations within range and plot
PlotRange -> {-2, 2} for range of y on plot.
Mar
13
comment Limit of sequence
Plot[n Sin[2 Pi E Factorial[n]], {n, 0, 15}]
Mar
5
comment extract line from position data
@tintin FindCurvePath can make the ordering.
Mar
5
comment extract line from position data
Vectorize the image first to PDF for example via online.rapidresizer.com, then import that to Mma.
Oct
12
comment How can I stack plots so that they are aligned nicely?
Bad trick #2: FrameTicks -> {Automatic, {{.5, "+\[VeryThinSpace]0.5"}}}.
Oct
12
comment How can I stack plots so that they are aligned nicely?
This is hardly noticeable ... Could you put y-label on the right perhaps? FrameLabel -> {"x (Meter)", None, None, "y (Meter)"}
Jul
18
comment FindRoot equation-variable mismatch
I'm using a bisection routine now. I'd rather use FindRoot for elegance and accuracy.
Jun
11
comment How do I find the intersection of a closed 3D curve given by numerical data with a specified plane?
Why do you sample over such a broad interval? -Pi to Pi would suffice.
Jun
8
comment How to find major color in a picture?
@Guillochon Along this lines. Help notes on the function: The returned colors are ordered based on the size of the clusters they represent. The specifics of clustering I don't know, it could be something cleverer than euclidean distance.
Jun
4
comment How do I find the coordinates of points in this image?
@cormullion I agree, should distance 2 not exclude certain original dot.
Jun
4
comment How do I find the coordinates of points in this image?
PixelValuePositions[Thinning@ColorNegate@ImageCrop@Binarize@image, 1] perhaps.
Jun
4
comment How do I find the coordinates of points in this image?
Are there really two thousand points in the original image (length of pts above)?
Jun
2
comment Solving differential equations with constraints
@KamovSergey If the constraints form a pattern of some sort you can encode you might want to look how to automate equations (WhenEvent is part of equation). You can do that. See help on WhenEvent, then Applications > Bouncing Balls. Or you could MapThread over the specification matrix. It shouldn't be hard to set up the whole problem elegantly I think.
Jun
2
comment Solving differential equations with constraints
I did something for x[t], try and stretch that to x'[t].
Jun
2
comment Solving differential equations with constraints
It's doing what it's specified to my understanding. Do you want the variables to remain at boundaries until force changes direction? Do you want perhaps the force to change direction upon hitting constraints? In that case you must introduce force as additional (discrete) variable in the equations of NDSolve.
May
30
comment Solve and plot an equation that is dependent on a transcendental equation
@nielsen Hey, no problem, and sure, feel free to pose questions. You might want to join chat though (top menu), there is a chat room "Discussion between BoLe and Aky", shall we converse there? Messages are stored and notifications done.
May
29
comment How to calculate the area of a listplot
Can you show the list resoluted-down perhaps? And could you close it to form a polygon for any practical purpose? For we know how to compute the polygon area...
May
29
comment Solve and plot an equation that is dependent on a transcendental equation
@nielsen I think you should think it over again...I added few results ("chapter 3").
May
29
comment Numbering nested list according with Depth (or Level)
let us continue this discussion in chat
May
29
comment Numbering nested list according with Depth (or Level)
@Aky Sure, I can share my secrets. :) Can you make a room or where do you want to chat?