Measuring distance between 2 "clumps" of data that meet certain conditions

For a project, i have data in the form of wind speed (m/s) recorded with 1 minute intervals, starting from 2009 through to 2021. For the time of each recording I have created a datetime array in the form of yyyy:MM:dd_HH:mm:ss, and for the wind speed recorded at each minute i have created a double array.

The wind speed ranges from 0 through to 40+ m/s. For the project, the machnes can safely operate between wind speeds of 0-20 m/s. The machinery is damaged and can fall over when wind speeds reach 30m/s and above, Therefore, i need to measure the time taken for the wind speed to go from 20 to 30 m/s. The data is measured by 1 minute increments, from 2009 - 2020, so the data is quite messy when plotted. I have been given the following conditions that simplify measuring the time taken to go from 20 - 30 m/s.

• When speed exceeds 20 m/s, the first 2 consequtive points above the 20 m/s limit will be the 'initial point'.
• when speed exceeds 30 m/s, the first 2 consequtive points above the 30 m/s limit will be the 'final point'.

I need to record the time taken between the 'initial point' and the 'final point'. As there is a lot of data, the cases where wind speed goes from 20-30 occures several times, and ill need to record the corresponding time taken for each case.

Thanks very much :)

Answer 1

[Yukthi S]

Hi Joshua,

To record the time intervals during which wind speeds escalate from 20 m/s to 30 m/s, we need a systematic approach to filter through the data, identify relevant 'initial' and 'final' points and then calculate the duration between these points.

Step-1: Initialize the arrays

    %Let windSpeeds_arr be the data of speeds of wind and dateTime_arr is the datetime array.
    %Let initial_ts and final_ts be the vectors which store the initial value timestamps and final value timestamps 
    %initializing initial_ts and final_ts
    initial_ts= [];
    final_ts= [];

Step-2: Identify ‘initial’ and ‘final’ points.

    i=1
    while i<=length(windSpeeds_arr)-1
    %initial point condition according to question
    if windSpeeds_arr(i)>20 && winSpeeds_arr(i+1) >20
    %storing initial points timestamps in a column vector
    initial_ts=[initial_ts;dateTime_arr(i)];
    %searching for corresponding final point
    %final point condition according to question
    for j=(i+1): length(windSpeeds_arr)-1
    if windSpeeds_arr(j)>30 && winSpeeds_arr(j+1)>30
    %storing initial points timestamps in a column vector
    final_ts=[final_ts;dateTime_arr(j)];
    i=j+1;
    break;
    end 
    end
    end
    i=i+1;
    end

Step-3: Calculate time intervals

    %Calculate the time intervals between initial and final timestamps
    timeIntervals= [];
    for k=1: length(initial_ts)
    time_duration=final_ts(k)-initial_ts(k);
    timeIntervals= [ timeIntervals;minutes(time_duration)]; % Convert the duration to minutes and store
    end
    % Display the calculated time intervals
    disp(timeIntervals);

The above code snippet will give you a basic idea of how to implement the logic to record time between ‘initial’ and ‘final’ points. You might want to adjust the logic depending on specific requirements.