Cut radio signal by hours

Hi

I have an excel file

I get in the file a date, hours and amplitude by frequency

How can I "cut" the hours as I wish

For example I want to get a new matrix but only between the hours of 00:00 and 12:00

Answer 1

[Walter Roberson]

https://www.mathworks.com/matlabcentral/answers/644295-how-do-to-get-a-specific-time-from-datetime-format-in-matlab#answer_541175

I26 = readtable(YourFileName);
mask = I26.time < hours(12);
selected_I26 = I26(mask,:);

This would extract only the entries before noon. <= if you want to include noon.

[Shahar ben ezra]

It works when I do this:

%%
clc, clear
my_date = readmatrix('matlab ex');
mask = (my_date(:,3) >= hours(19) | my_date(:,3) <= hours(07))
selected_I26 = my_date(mask,:)

Another question

When date and time are together, how do you split them into 2 different vectors?

Or alternatively filter them by time?

For column 2

[Walter Roberson]

In another Question, Steven pointed out timeofday()

[Shahar ben ezra]

First of all thank you so much for the help!

There is a possibility that you will write me an example because it does not work for me to divide the vector by hours and vector by date

[Walter Roberson]

t = YourTable{:,2};
t_since_midnight = timeofday(t);
t_date = t - t_since_midnight;

[Shahar ben ezra]

You are a king!

Thanks!!!!!

[Shahar ben ezra]

Sorry for all the questions

I'm just getting a little confused with this because it's new to me

How do I make a matrix with a duration array

And a connector with a table-type array

Then I have to do the filtering

Do I have to move to numeric numbers?

the code:

clc, clear

my_date = readtable('matlab ex');
date_and_time = my_date{:,2};
vec_hours_only = timeofday(date_and_time);
vec_date_only = date_and_time - vec_hours_only;
Data=my_date(:,4:end);
my_new_matrix = (vec_hours_only,Data)  % problem ,not work

mask = (my_new_matrix(:,1) >= hours(00) | my_new_matrix(:,1) <= hours(12));

The_information_I_need = my_new_matrix(mask,:);

[Walter Roberson]

my_new_matrix = [table(vec_hours_only), Data];

mask = my_new_matrix{:,1} <= hours(12);

There is no point in testing >= hours(00) because you are using a time of day and times of day cannot be negative (not even when leap seconds are added or deleted!)

[Shahar ben ezra]

Really thank you so much!

[Peter Perkins]

Walter's solution(s) are correct, but I recommend that for your first spreadsheet, you combine the date and time, and in the second you don't split them apart. Then turn your table into a timetable.

Recent versions of MATLAB have made importing durations more automatic, so you may or may not get durations automatically.

t = readtable("yourFile.xlsx")
t.data = t.data + t.time; % or t.data + duration(t.time)
tt = table2timetable(t(:,[1 4:end],'RowTimes',t.data);

ttMorning = tt(tt.Time.Hour <= 12,:);

[Shahar ben ezra]

Tnx Peter Perkins :)

I will try that too