How can I subtract the times without considering the date in question?

조회 수: 11(최근 30일)
Newbie
Newbie 2021년 8월 11일
댓글: Scott MacKenzie 2021년 8월 12일
I have a vector of time which are linked to dates but I only want to subtract the times from each other without considering the dates too. For example, I want to do 4:30 - 3:30 is equal to 1 hour and then 3:30 - 2:50 is equal to 40 minutes (0.6666667) and etc. I dont want Matlab to consider the date period basically.
I have this code for the time from 25-Apr to 01-May but it does take into account the date too:
out1m=24-(seconds(diff(datetime([T_Smooth{2,4};T_Smooth{3,4}])))/3600);
Can anyone help please? Thank you.
  댓글 수: 2

댓글을 달려면 로그인하십시오.

채택된 답변

Cris LaPierre
Cris LaPierre 2021년 8월 11일
편집: Cris LaPierre 2021년 8월 11일
Use the timeofday function.
% create vector of datetimes
date = datetime(2019,[4;4;5;5],[24;25;1;2],[4;3;2;4],[30;30;50;30],0)
date = 4×1 datetime array
24-Apr-2019 04:30:00 25-Apr-2019 03:30:00 01-May-2019 02:50:00 02-May-2019 04:30:00
% Take difference of the times.
dt = diff(timeofday(date))
dt = 3×1 duration array
-01:00:00 -00:40:00 01:40:00
Use the hours function to turn hh:mm:ss into decimal hours if you want.
hours(dt)
ans = 3×1
-1.0000 -0.6667 1.6667

추가 답변(1개)

Scott MacKenzie
Scott MacKenzie 2021년 8월 11일
편집: Scott MacKenzie 2021년 8월 11일
Here's one way to do this:
% test data (one month in 30-min increments)
dt = datetime(2021,4,1):minutes(30):datetime(2021,5,1);
% indices of datetime elements to compute hour difference between
n1 = 154;
n2 = 255;
x = datenum(dt(n2) - dt(n1));
hrs = rem(x,1) * 24
hrs = 2.5000
  댓글 수: 5
Scott MacKenzie
Scott MacKenzie 2021년 8월 12일
Oops, yes, I used datenum as well. Thanks for pointing that out. The language to discourage use of this function could be a tad stronger, however. Below is what appears for xlsread, as an example.

댓글을 달려면 로그인하십시오.

Community Treasure Hunt

Find the treasures in MATLAB Central and discover how the community can help you!

Start Hunting!

Translated by