Matplotlib Time Series Plot Trajectory Issue

Question

I am trying to plot time series data to tell visually if there are any points that stand out as outliers. I am still familiarizing myself with matplotlib , but I figured from my data set and setup, I would be able to plot my unit variable on the Y axis and Date on the X Axis and see trends on a daily basis. However, it appears that there is some sort of running total aggregation going on as there is almost a perfectly linear line for the plots from the first date to the last. What is off with my configuration that could be causing this?

Here is my data (I am plotting date and units ):

    month       date    units   ler sales
513   May 2019-05-28      811    94   42
514   May 2019-05-29      807    59   28
515   May 2019-05-30      768    68   24
516   May 2019-05-31      675    60   27

Here is my code:

df_t_3_months // Data Set

plt.figure(figsize=(10,8))
plt.subplot(211)
plt.plot_date(df_t_3_months['date'],df_t_3_months['units'],xdate=True)

Here is the resulting plot:

I was expecting a horizontal pattern with peaks and valleys, as one would expect with consistent time series data

Answer 1

尝试plt.plot(df_t_3_months['date'], df_t_3_months['units'].astype(float))