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0
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53
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The plots appear weird after 200+ timesteps
I am trying to simulate grain boundary properties in a ferroelectric bicrystal using FiPy.
I have basically three variables to solve namely, degree of crystalinity (eta), polarization magnitude in the ...
-1
votes
1
answer
667
views
How do I force solve_ivp to take a smaller time step from within the function it calls
I have a function call of the form
ans = scipy.integrate.solve_ivp(dfdz, zbounds, f0, method='RK45', args=argslist, t_eval = zspan, vectorized=True)
If the solver takes a timestep that's too big, ...
1
vote
1
answer
364
views
Fix Your Timestep: Why not just plug in the remaining dt?
Gaffer suggests doing linear interpolation between the previous state and the current state for rendering. The current state is 1 full fixed timestep apart from the previous state. But why not just ...
1
vote
3
answers
585
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How to calculate the frame timestep/deltatime in an MTKView?
I want to get the time since the last frame (known as the timestep or deltatime) in the draw method of MTKView. I expect to see values of approximately 0.017 assuming 60 frames per second consistently....
-1
votes
1
answer
85
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Timestep multiple items dataframe
I have such dataframe:
product1
product2
product3
product4
product5
time
straws
orange
melon
chair
bread
1
melon
milk
book
coffee
cake
2
bread
bananas
juice
chair
book
3
straws
coffee
cake
milk
orange
...
-1
votes
1
answer
163
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How to speed up the world in LibGDX without altering delta time
This is not a duplicate of this question because I need a way to speed up my world without changing deltaTime and have everything happen faster. Why can't I use deltaTime or change it? I'm using the ...
-1
votes
1
answer
429
views
Transform hourly data in minute timestep data
I have an Excel file with hourly data, that is 8760 values on one year.
I need to have data at the minute-step.
I need to take the hourly value, and copy it to the 60 cells over and over again, until ...
1
vote
1
answer
325
views
step doubling Runge Kutta implementation stuck shrinking stepsize to machine precision
I need to integrate a system of ODES using an adaptive RK4 method with stepsize control via step doubling techniques.
The problem is that the program continues forever shrinking the stepsize down to ...
1
vote
1
answer
766
views
NCO: is there any one-line command to change the index of time dimension as a whole array (not by for-loop)?
I have a netCDF file FORCING.nc containing dimension "time" with values like: [ 841512., 841513., 841514., ..., 1051893., 1051894.,1051895.]. But I want to change the time stamps from the ...
0
votes
1
answer
147
views
Influx at specific time with changing time step in DeSolve
I am making a population distribution model with ODEs and DDEs in DeSolve with the method lsoda.
In this model I want to have an influx of the population at a specific time (a specific day).
A very ...
0
votes
1
answer
399
views
Python Gravity Simulator only plots straight lines
I'm trying to make a basic gravity sim using py but for some reason it plots all the lines as straight, I looked at a couple of examples when I got stuck but they all use similar equations / ways of ...
2
votes
1
answer
385
views
Is it possible to update funcion variables every time it's been called?
I'm trying to solve an ODE system with solve_ivp and i want to change the local variables of the function every time it's been called by the solver.
In particular I wand to update the lagrange ...
2
votes
2
answers
2k
views
Is there an NCO command to change the time stamp of a variable in a netcdf?
I have a netcdf file containing maximum daily air temperature, time, lat and lon. I successfully got maximum temperature from a netcdf of 6 hourly temperatures using the nco command:
ncra -y max --mro ...
1
vote
1
answer
764
views
Python3.7 function to plot datetime from timestep of netCDF4
I need to plot bg variable from netcdf file, however the time is expressed as time-step.
I read the netcdf file:
data =netCDF4.Dataset (r'D:\Users\NOAA\\CT2019B.molefrac_components_glb3x2_2014-2018.nc'...
0
votes
1
answer
200
views
maximum time step of IDA solver in Open Modelica
In Open Modelica, in the settings of IDA solver, we can define the initial and maximum time step as well. In a simulation, I have set these parameters, but after simulation and checking the solutions ...