Use Python Pandas DataFrames in MATLAB - MATLAB & Simulink - MathWorks 日本 (2024)

• You can convert a pandas DataFrame to a MATLAB table using the table function. You can also convert a pandas DataFrame to a MATLAB timetable using the timetable function.

• You can convert a MATLAB table or timetable to a pandas DataFrame using the py.pandas.DataFrame function. You can also pass MATLAB tables or timetables directly to Python functions without converting them to pandas DataFrames first.

Convert Pandas DataFrame to MATLAB Table

Convert a pandas DataFrame to a MATLAB table using the table function.

For example, create a pandas DataFrame and convert it to a MATLAB table. In this case, MATLAB converts the pandas Series to MATLAB strings and converts the Python integer values to MATLAB integer values.

last_names = py.pandas.Series({"Sanchez","Johnson","Zhang","Diaz","Brown"},dtype="object");age = py.numpy.random.randint(18,high=85,size=py.len(last_names));height = py.numpy.random.randint(60,high=78,size=py.len(last_names));pd = py.pandas.DataFrame(struct("LastName",last_names,"Age",age,"Height",height));md = table(pd)

md=5×3 table LastName Age Height _________ ___ ______ "Sanchez" 61 65 "Johnson" 46 62 "Zhang" 68 61 "Diaz" 34 72 "Brown" 80 65 

Convert Pandas DataFrame to MATLAB Timetable

If you have a pandas DataFrame that contains timestamped values, you can convert it to a MATLAB timetable using the timetable function:

For example, create a pandas DataFrame and convert it to a MATLAB timetable. In this case, MATLAB converts the Python datetime values to MATLAB datetime values.

date_today = py.datetime.datetime.now();mtimes = py.pandas.date_range(date_today,periods=3,freq='S');temp = py.list({double(37.3),double(39.1),double(42.3)});pressure = py.list({int32(30.10),int32(30.56),int32(28.90)});wspeed = py.list({single(13.4),single(6.5),single(7.3)});ptt = py.pandas.DataFrame(struct("MeasurementTime",mtimes, ... "Temp",temp,"Pressure",pressure,"WindSpeed",wspeed));mtt = timetable(ptt)

mtt=3×3 timetable MeasurementTime Temp Pressure WindSpeed ____________________ ____ ________ _________ 01-Feb-2024 13:51:50 37.3 30 13.4 01-Feb-2024 13:51:51 39.1 31 6.5 01-Feb-2024 13:51:52 42.3 29 7.3 

Convert MATLAB Table to Pandas DataFrame

MATLAB implicitly converts any MATLAB table passed to a Python function into a pandas DataFrame. However, if you have a MATLAB table, you can explicitly convert it to a pandas DataFrame using py.pandas.DataFrame.

For example, create a MATLAB table and convert it to a pandas DataFrame.

dish_name = ["omelette";"soup";"salad";"fries";"cookie"];price = [8.50;5.00;7.25;1.50;2.00];sold_out = [true;false;true;false;true];md = table(dish_name,price,sold_out);pd = py.pandas.DataFrame(md);py.print(pd)

 dish_name price sold_out0 omelette 8.50 True1 soup 5.00 False2 salad 7.25 True3 fries 1.50 False4 cookie 2.00 True

You can also pass MATLAB tables directly to Python functions without converting them to pandas DataFrames first. For example, find the length of md using py.len.

l = py.len(md)

l = Python int with properties: denominator: [1×1 py.int] imag: [1×1 py.int] numerator: [1×1 py.int] real: [1×1 py.int] 5

Convert MATLAB Timetable to Pandas DataFrame

You can convert MATLAB timetables to pandas DataFrames using py.pandas.DataFrame.

For example, create a MATLAB timetable and convert it to a pandas DataFrame.

mtt = timetable(datetime(["2023-12-18";"2023-12-19";"2023-12-20"]), ... [37.3;39.1;42.3],[30.1;30.03;29.9],[13.4;6.5;7.3]);mtt.Properties.VariableNames = ["Temp","Pressure","WindSpeed"];ptt = py.pandas.DataFrame(mtt);py.print(ptt)

 Temp Pressure WindSpeedTime 2023-12-18 37.3 30.10 13.42023-12-19 39.1 30.03 6.52023-12-20 42.3 29.90 7.3

Data Type Conversion from Pandas DataFrames to MATLAB Tables or Timetables

When you convert a pandas DataFrame to a MATLAB table or timetable, MATLAB automatically converts these pandas data types to MATLAB types. In this table, py. refers to built-in Python data types, np. refers to NumPy, and pd. refers to pandas.

Data Type Conversion from MATLAB Tables or Timetables to Pandas DataFrame

When you call a Python function with a MATLAB table or you explicitly convert a MATLAB table or timetable to a pandas DataFrame, MATLAB automatically converts the table data into types that best represent the data in the pandas language. In this table, py. refers to built-in Python data types, np. refers to NumPy, and pd. refers to pandas.

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