Sum Frequency / Duration Curve

A sum frequency plot (also known as a duration curve or Jahresdauerlinie) shows sorted values against their rank.

• reverse=False (default): lowest value at x=0 (R convention)

• reverse=True: highest value at x=0 (classic duration curve)

All plots are interactive — hover to see exact values.

import plotly.io as pio
pio.renderers.default = "notebook_connected"

import pandas as pd
from importlib import resources

data_path = resources.files("pyedautils") / "data" / "outside_temp.csv"
df = pd.read_csv(data_path, sep=";")
df.head()

	timestamp	value
0	2018-03-21 11:00:00	5.20
1	2018-03-21 12:00:00	6.70
2	2018-03-21 13:00:00	6.40
3	2018-03-21 14:00:00	6.00
4	2018-03-21 15:00:00	5.25

Daily — Ascending (R default)

from pyedautils.plots import plot_sum_frequency

fig = plot_sum_frequency(
    data=df,
    resolution="daily",
    year=2019,
    ylab="Temperature (°C)",
)
fig.show()

Hourly — Ascending

fig = plot_sum_frequency(
    data=df,
    resolution="hourly",
    year=2019,
    ylab="Temperature (°C)",
)
fig.show()

Daily — Duration Curve (reverse=True)

With reverse=True, the highest value starts at x=0. This is the classic “Jahresdauerlinie” representation.

fig = plot_sum_frequency(
    data=df,
    resolution="daily",
    year=2019,
    reverse=True,
    title="Duration Curve — Daily (2019)",
    ylab="Temperature (°C)",
)
fig.show()