Call vector by key

I would like to save some weather data in a container. The data consists of forecasts and actuall values for the years 2016-2018. To acces the data I want to use the years as a key, so when I call

windSpeedForecast(2016)

it will give me a vector with all hourly windSpeedForecasts of 2016, so a 8760x1 vector.

The default containers in Matlab are only able to save scalars as values and not vectors. Is there a way to achieve this or am I missing something in the containers.Map object?

Thanks in advance.

Best regards,

Stefan

Answer 1

[Bruno Luong]

Work for me

>> M=containers.Map('KeyType','double','valueType','any')

M = 

  Map with properties:

        Count: 0
      KeyType: double
    ValueType: any

>> M(2020)=double('Covid')

M = 

  Map with properties:

        Count: 1
      KeyType: double
    ValueType: any

>> char(M(2020))

ans =

    'Covid'

>> 

[Stefan M]

Hi Bruno,

thanks for your answer. You are saving a scalar double as the value but I want to save a vector so

>> M(2020)

will give me the output

ans =

    12.3    10.2    8.7 ...

[Bruno Luong]

in my example

>> double('Covid')

ans =

    67   111   118   105   100

>> 

IS a VECTOR not a scalar. You can replace it with [12.3 10.2 8.7] is you want. try it.

[Walter Roberson]

Stefan: make sure you use 'ValueType', 'any'

[Stefan M]

Hi Bruno,

thanks for the clarification. I misread your example and did forget to pass 'ValueType', 'any'. Now it works

@Walter thank you, too

Answer 2

[Steven Lord]

Depending on what else you want to do with this data, storing it in a timetable may be useful. Using one of the examples on the documentation page for timetable:

MeasurementTime = datetime({'2015-12-18 08:03:05';'2015-12-18 10:03:17';'2015-12-18 12:03:13'});
Temp = [37.3;39.1;42.3];
Pressure = [30.1;30.03;29.9];
WindSpeed = [13.4;6.5;7.3];
TT = timetable(MeasurementTime,Temp,Pressure,WindSpeed)

Now let's retrieve all the rows with times between 9 AM and 1 PM on the date in question:

selectedTimes = timerange(datetime('2015-12-18 09:00:00'), datetime('2015-12-18 13:00:00'));
X = T(selectedTimes, :) 

This particular example does not include any non-scalar data, but it is possible to store such data in a timetable variable.