海面水温の長期変化傾向（全球平均）

code:p.py

import pandas as pd

import matplotlib.pyplot as plt

dataset = pd.read_csv('temperature.csv')

plt.plot(dataset.YEAR, dataset.ANOMALY)

plt.show()

code:temperature.csv

YEAR,ANOMALY

1891,-0.58

1892,-0.68

1893,-0.72

1894,-0.71

1895,-0.59

1896,-0.46

1897,-0.48

1898,-0.64

1899,-0.57

1900,-0.49

1901,-0.58

1902,-0.64

1903,-0.73

1904,-0.77

1905,-0.63

1906,-0.60

1907,-0.70

1908,-0.79

1909,-0.78

1910,-0.79

1911,-0.77

1912,-0.62

1913,-0.69

1914,-0.56

1915,-0.48

1916,-0.67

1917,-0.67

1918,-0.59

1919,-0.55

1920,-0.55

1921,-0.56

1922,-0.60

1923,-0.59

1924,-0.57

1925,-0.51

1926,-0.42

1927,-0.51

1928,-0.55

1929,-0.55

1930,-0.43

1931,-0.40

1932,-0.49

1933,-0.53

1934,-0.49

1935,-0.47

1936,-0.41

1937,-0.32

1938,-0.40

1939,-0.42

1940,-0.31

1941,-0.22

1942,-0.29

1943,-0.31

1944,-0.17

1945,-0.22

1946,-0.41

1947,-0.41

1948,-0.37

1949,-0.35

1950,-0.41

1951,-0.30

1952,-0.28

1953,-0.29

1954,-0.45

1955,-0.50

1956,-0.47

1957,-0.27

1958,-0.27

1959,-0.35

1960,-0.39

1961,-0.36

1962,-0.37

1963,-0.32

1964,-0.47

1965,-0.42

1966,-0.36

1967,-0.39

1968,-0.35

1969,-0.22

1970,-0.36

1971,-0.48

1972,-0.29

1973,-0.32

1974,-0.46

1975,-0.50

1976,-0.48

1977,-0.32

1978,-0.35

1979,-0.23

1980,-0.24

1981,-0.31

1982,-0.30

1983,-0.23

1984,-0.32

1985,-0.33

1986,-0.28

1987,-0.15

1988,-0.23

1989,-0.26

1990,-0.17

1991,-0.17

1992,-0.25

1993,-0.23

1994,-0.21

1995,-0.16

1996,-0.17

1997,-0.01

1998,0.02

1999,-0.17

2000,-0.14

2001,-0.03

2002,-0.01

2003,0.01

2004,0.00

2005,0.02

2006,0.01

2007,-0.06

2008,-0.06

2009,0.06

2010,0.07

2011,-0.03

2012,0.02

2013,0.07

2014,0.13

2015,0.23

2016,0.26

2017,0.19

2018,0.15

2019,0.24

2020,0.23

2021,0.14

2022,0.17

2023,0.40

2024,0.44

YEAR をdatetime型に変換し、index に用いる。

code:p.py

import pandas as pd

import matplotlib.pyplot as plt

plt.plot(dataset.ANOMALY)

plt.show()

Series型オブジェクトを plot 関数に与えると、横軸には index が用いられる。

YEAR系列を datetime 型に変換した際、欠落している月日については 01-01 で補間されている。