All Questions
26 questions
1
vote
2
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115
views
Numerical Stiffness Issue in NDSolve for Stiff ODE System: How to Avoid Extrapolation Errors?
I am trying to solve a stiff system of ode differential equations (ODEs) using NDSolve in Wolfram Mathematica. The problem is related to modeling the dynamics of proteins over time, with parameters ...
-2
votes
1
answer
86
views
Novice Mathematica User: Plots are very small despite changing image size option
I'm currently writing a paper about marine chemistry and I'm trying to include a reactive transport model that was written in mathematica by a collaborator. I have a lot of experience in SAS, but I ...
- 1
5
votes
3
answers
307
views
Plotting Incidence function of the SIR Model
I am working on the SIR model and I am trying to plot the incidence function on a specific time interval.
...
4
votes
2
answers
125
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ParametricPlot for phase field error (case: Predator-Prey Model) [closed]
so I have a task that need to draw a phase field of predator-prey model, but first I tried my lecturer's coding:
...
- 41
0
votes
0
answers
279
views
How to plot elements from an array?
Im trying to solve a differential equation for a range of parameters (1->4). I then want to automatically plot a graph for each of those parameters.
...
- 1
1
vote
0
answers
118
views
Non linear differential equation plot [closed]
Consider the following paper:
https://reader.elsevier.com/reader/sd/pii/S0096300306007715?token=2B98E3B12F1E623C99A0787996469AF36E8EF230F6ED5289EAFB60B64CE79A6ACCF74B946A34F3370C65D4FC99018648&...
- 407
3
votes
0
answers
135
views
Graph embedding constrained to a surface?
Have been contemplating it for a while, but did not dare to post as I felt like this must be a major undertaking to implement. Then saw the excellent answers to a recent question RegionPlot3D KnotData ...
- 2,182
0
votes
1
answer
115
views
Equation Plotting
I'm using the mean field theory approximation and the Ising Model for magnetization to come up with the following equation:
m(T) = tanh(m(T)/T)
where T is an ...
- 1
2
votes
3
answers
224
views
2
votes
1
answer
422
views
How to Make a Bifurcation plot of a non linear system of ODEs
I am modelling bacterial growth. I have a quite difficult non linear systems of ODE's. I have 2 bacteria that i'm modelling with competition, as wel as transfer to a different place. so there are 2 ...
- 21
0
votes
0
answers
101
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Error in Monte Carlo simulation. Now Random walk (dotted curve) doesn't fit to the analytical curve (dashed curve)
I've been trying to code a kinetic monte carlo simulation for a system of consecutive chemical reactions using a fixed (repaired) code that the user flinty gives me in the last questions I post:
...
- 13
1
vote
1
answer
98
views
Strange error not found in a monte carlo code, Infinite expression 1/0 encountered
I've been trying to code a kinetic monte carlo simulation for a dimerization reaction, 2M ---> D. However I have a kinetic Monte Carlo code for a first order decomposition reaction of AIBN (that's ...
- 13
4
votes
1
answer
96
views
Trying to recreate a plot which tracks the age of individuals inside a compartment model
I am using a compartment model from this paper.
I am trying to recreate Figure 6. I will be honest, I have no clue how to approach this. The paper doesn't give information on how to achieve the ...
- 57
1
vote
1
answer
123
views
How can I get a plot of "surface area coverage" of a parametric plot?
I have a parametric function defined by the x and y functions:
...
user72418
-4
votes
1
answer
235
views
3D Plotting and optimising on the surface area of a spherical gyroid [closed]
*this is an equation of a shperical gyroid emphasized texti want to plot it in mathematica and obtain the shapes like those on the picture below. sinxcosy + sinycosz + sinzcosx = 0
i also want to know ...
0
votes
0
answers
2k
views
Help with "Coordinate should be a pair of numbers, or a Scaled or Offset form."
I am plotting the pair of recurrence relations:
...
- 83
5
votes
1
answer
877
views
Mathematica code for bifurcation diagram in 3D
Good day. I need help with the code in mathematica to plot the bifurcation diagram (e vs z*) or (e vs x*), for the system ...
- 99
2
votes
1
answer
211
views
Fitting data with 3 linear fits
I have a dataset that can be easily approximated by a piecewise function composing of 3 linear functions, but i am unable to get an accurate fit once the third linear function is required. The model ...
- 63
0
votes
1
answer
493
views
Model fitting for concave curve: test if asymptote or convergence exist
I am asking a double check if conceptually I set up proper model and proceeding in good direction to drive conclusions.
I have a distribution that looks like this:
I want to test if for increasing x ...
- 467
0
votes
0
answers
172
views
Help to model fitting a distribution of weights in weighted graphs : power or exponential law?
I found this post https://math.stackexchange.com/questions/164436/difference-between-power-law-distribution-and-exponential-decay
useful, but not sufficient for me to understand which law may best ...
- 467
42
votes
5
answers
15k
views
8
votes
1
answer
743
views
Computing launch parameters for hitting a point in 3D with projectile under influence of wind
The end goal of this problem is to compute functions which describe the launch parameters which are needed to hit a specified goal in 3D in the presence of wind disturbances. This is as far I have ...
- 492
4
votes
3
answers
1k
views
Plot Plane to Intersect 3D Contour Plot in Mathematica
I have a 3D model of a heart in Mathematica and I'm trying to create a plane so that the open surface (as seen in the image below) is cut off so that the heart can have a solid, level surface. How ...
- 145
7
votes
0
answers
478
views
How can I model the volatility, using a GARCH(1,1), of a time series of returns (and plot it) using Mathematica? [closed]
I know that if I use this code:
tsm = TimeSeriesModelFit[ret, {"GARCH", {1, 1}}];
I can get the parameters using this:
...
- 205
6
votes
1
answer
810
views
Plot two functions within manipulate
I just want to plot all stochastic processes and their average process.
The original code without the average is:
...
- 361
2
votes
1
answer
757
views
