Curve Fitting to a time series in the format ‘datetime’?

by

Instead of plotting datenums, use the associated datetimes.

import numpy as np
import matplotlib.pyplot as plt
import matplotlib.dates as mdates
import datetime as DT
import time

dates = [DT.datetime(1978, 7, 7),
     DT.datetime(1980, 9, 26),
     DT.datetime(1983, 8, 1),
     DT.datetime(1985, 8, 8)]

y = [0.00134328779552718,
     0.00155187668863844,
     0.0039431374327427,
     0.00780037563783297]


yerr = [0.0000137547160254577,
        0.0000225670232594083,
        0.000105623642510075,
        0.00011343121508]

x = mdates.date2num(dates)

z4 = np.polyfit(x, y, 3)
p4 = np.poly1d(z4)

fig, cx = plt.subplots()

xx = np.linspace(x.min(), x.max(), 100)
dd = mdates.num2date(xx)

cx.plot(dd, p4(xx), '-g')
cx.plot(dates, y, '+', color="b", label="blub")
cx.errorbar(dates, y,
             yerr,
             marker=".",
             color="k",
             ecolor="b",
             markerfacecolor="b",
             label="series 1",
             capsize=0,
             linestyle="")

cx.grid()
cx.set_ylim(0, 0.03)
plt.show()

yields

enter image description here

Note in your code, x represented a list of datetimes, and d represented numbers. I’ve decided to reverse that: I use dates for a list of datetimes, and x to represent numbers.

More Related Contents:

  1. Converting datetime.date to UTC timestamp in Python
  2. Format timedelta to string
  3. How to convert local time string to UTC?
  4. Filtering Pandas DataFrames on dates
  5. How to print pandas DataFrame without index
  6. Converting string with UTC offset to a datetime object [duplicate]
  7. How do I convert a datetime to date?
  8. Trying to mock datetime.date.today(), but not working
  9. Most recent previous business day in Python
  10. Convert string date to timestamp in Python
  11. Getting today’s date in YYYY-MM-DD in Python?
  12. type object ‘datetime.datetime’ has no attribute ‘datetime’
  13. How to change the datetime tick label frequency for matplotlib plots
  14. python – datetime with timezone to epoch
  15. Python speed testing – Time Difference – milliseconds
  16. How to get UTC time in Python?
  17. fitting data with numpy
  18. Fit a gaussian function
  19. Parameter unsupported when inserting int
  20. In Pandas how do I convert a string of date strings to datetime objects and put them in a DataFrame?
  21. Python – Convert string representation of date to ISO 8601
  22. time data does not match format
  23. pd.to_datetime is getting half my dates with flipped day / months
  24. Pyspark changing type of column from date to string
  25. Show decimal places and scientific notation on the axis
  26. Get day name from datetime
  27. Creating graph with date and time in ticklabels with matplotlib
  28. How do I convert timestamp to datetime.date in pandas dataframe?
  29. Rotate axis tick labels
  30. Pandas: select all dates with specific month and day

Leave a Comment