File:SineMapOrbitDiag InitNearZero.png

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Summary

Description
English: Made by the following code, adapted from Wikipedia article on Logistic function:
import numpy as np
import math
import matplotlib.pyplot as plt

preset = 5

markerSize = 0.001
saveFigure = True
markerStyle = "," # . - point; , - pixel
if preset == 1: # Diagram with positive c values in [0, 1]
  presetNote = "Initialize to 0\n; limit c to [0, 1] despite interesting patterns existing outside of it"
  presetNote = ""
  cInterval = (0, 1)
  cResolution = 0.0001
  mapIterationCount = 1000
  lastMapIterationCountToPlot = 1000
  startingIterationValue = 0.5
  fileName = "SineMapOrbitDiag.png"
  yLim = (0, 1)
if preset == 2: # Diagram with positive and negative c values
  presetNote = "Initialize to 0\n"
  cInterval = (-4, 4)
  cResolution = 0.001
  mapIterationCount = 500
  lastMapIterationCountToPlot = 500
  startingIterationValue = 0.5
  fileName = "SineMapOrbitDiag_BroadCRange.png"
  yLim = (-4, 4)
if preset == 3: # Diagram with positive and negative c values, larger interval
  presetNote = "Initialize to 0\n"
  cInterval = (-10, 10)
  cResolution = 0.002
  mapIterationCount = 500
  lastMapIterationCountToPlot = 500
  startingIterationValue = 0.5
  fileName = "SineMapOrbitDiag_BroadCRange2.png"
  yLim = (-10, 10)
if preset == 4: # Zoom on the bifurcation period doubling region
  presetNote = "Initialize to 0; zoom on the bifurcation period doubling region\n"
  cInterval = (0.84, 0.8657)
  cResolution = 0.000005
  mapIterationCount = 200
  lastMapIterationCountToPlot = 200
  startingIterationValue = 0.5
  fileName = "SineMapOrbitDiag_BifurcZoom.png"
  yLim = (0.3, 0.9)
if preset == 5: # Diagram with positive c values in [0, 1], init near zero
  presetNote = "Initialize to 1E-10 = near zero\n"
  cInterval = (0, 1)
  cResolution = 0.0001
  mapIterationCount = 500
  lastMapIterationCountToPlot = 500
  startingIterationValue = 1E-10
  fileName = "SineMapOrbitDiag_InitNearZero.png"
  yLim = (0, 1)
  
lims = np.zeros(mapIterationCount)

fig, biax = plt.subplots()
fig.set_size_inches(16, 9)

itemCount = 0
for c in np.arange(cInterval[0], cInterval[1], cResolution):
  itemCount += 1
  lims[0] = startingIterationValue
  for i in xrange(mapIterationCount - 1):
    lims[i + 1] = c * math.sin(math.pi * lims[i])
  if itemCount % 1000 == 0:
    print("Parameter values processed:", itemCount)

  biax.plot([c] * lastMapIterationCountToPlot,
            lims[(mapIterationCount - lastMapIterationCountToPlot):], "b.",
            markersize=markerSize,
            marker=markerStyle)

biax.set(xlabel="c", ylabel="x",
         title="Sine map - c * sin(pi * x) - bifurcation diagram/orbit diagram" + "\n" +
                presetNote +
               "c resolution: " + str(cResolution) +
               ", iteration count: " + str(mapIterationCount) +
               ", last values to plot count: " + str(lastMapIterationCountToPlot))

biax.set_ylim(yLim[0], yLim[1])
if saveFigure:
  plt.savefig(fileName, dpi=600)
else:
  plt.show()
Date
Source Own work
Author Dan Polansky

Licensing

I, the copyright holder of this work, hereby publish it under the following license:
w:en:Creative Commons
attribution
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You are free:
  • to share – to copy, distribute and transmit the work
  • to remix – to adapt the work
Under the following conditions:
  • attribution – You must give appropriate credit, provide a link to the license, and indicate if changes were made. You may do so in any reasonable manner, but not in any way that suggests the licensor endorses you or your use.

Captions

An orbit diagram for the sine map, with the initial value near 0 rather than 0.5

Items portrayed in this file

depicts

8 February 2024

File history

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Date/TimeThumbnailDimensionsUserComment
current13:45, 8 February 2024Thumbnail for version as of 13:45, 8 February 20249,600 × 5,400 (1.58 MB)Dan PolanskyUploaded own work with UploadWizard

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