how to make datetime data readable and convert to julian date?

28 Dec 2022
1 Answer
Answer Accepted
Updated 28 Dec 2022
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greeting sir, I want to convert date time with YYYY/MM/DD HH:MM:SS format in my file to julian date. When I load my data, the datenumber changed to NaN
This is what I've tried
clc;clear; close all;
% Specify the folder where the files live.
myFolder = 'C:\ZTD\CSV';
% Check to make sure that folder actually exists. Warn user if it doesn't.
if ~isfolder(myFolder)
errorMessage = sprintf('Error: The following folder does not exist:\n%s\nPlease specify a new folder.', myFolder);
uiwait(warndlg(errorMessage));
myFolder = uigetdir(); % Ask for a new one.
if myFolder == 0
% User clicked Cancel
return;
end
end
Allfile = fullfile(myFolder, '*.txt'); % Change to whatever pattern you need.
List = dir(Allfile);
for k = 1 : length(List)
sites = List(k).name;
num = readmatrix(sites,"NumHeaderLines",1);
num(:,end)=[];
time = num(1:end,1);
% % julian date corresponding to 2000-01-01 00:00:00.0
mjd20000 = 51544;
How to make my date time data readable and calculate it to julian date?

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 Accepted Answer

VBBV
VBBV on 28 Dec 2022
Ran in:

0 votes

Ran in:
use readtable instead of readmatrix
D = readtable('dd.txt') % use readtable
Warning: Column headers from the file were modified to make them valid MATLAB identifiers before creating variable names for the table. The original column headers are saved in the VariableDescriptions property.
Set 'VariableNamingRule' to 'preserve' to use the original column headers as table variable names.
D = 4259×19 table
Date_Asia_Jakarta_ Tempin__C_ Temp__C_ Chill__C_ Dewin__C_ Dew__C_ Heatin__C_ Heat__C_ Humin___ Hum___ Wspdhi_m_s_ Wspdavg_m_s_ Wdiravg___ Bar_hPa_ Rain_mm_ Et_mm_ Rainrate_mm_h_ Solarrad_W_m__ Uvi__ __________________ __________ ________ _________ _________ _______ __________ ________ ________ ______ ___________ ____________ __________ ____________ ________ ______ ______________ ______________ _____ 01/01/2022 00:00 27.3 25.3 25.3 NaN 23.3 NaN 25.3 52 89 1.5 1.1 229 {'1,010.90'} 0 NaN 0 0 0 01/01/2022 00:10 27.3 25.1 25.1 NaN 23.3 NaN 25.1 52 90 0 0 226 {'1,010.80'} 0 NaN 0 0 0 01/01/2022 00:20 27.3 25 25 NaN 23.2 NaN 25 52 90 0 0 226 {'1,010.40'} 0 NaN 0 0 0 01/01/2022 00:30 27.3 24.9 24.9 NaN 23.4 NaN 24.9 52 91 0 0 226 {'1,010.20'} 0 NaN 0 0 0 01/01/2022 00:40 27.3 24.9 24.9 NaN 23.4 NaN 24.9 52 91 0 0 226 {'1,010.30'} 0 NaN 0 0 0 01/01/2022 00:50 27.2 24.8 24.8 NaN 23.3 NaN 24.8 52 91 0.5 0.4 226 {'1,010.20'} 0 NaN 0 0 0 01/01/2022 01:00 27.1 24.8 24.8 NaN 23.3 NaN 24.8 52 91 0 0 226 {'1,010.10'} 0 NaN 0 0 0 01/01/2022 01:10 27.2 24.8 24.8 NaN 23.5 NaN 24.8 52 92 0 0 226 {'1,010.20'} 0 NaN 0 0 0 01/01/2022 01:20 27.2 24.8 24.8 NaN 23.3 NaN 24.8 52 91 0 0 226 {'1,010.10'} 0 NaN 0 0 0 01/01/2022 01:40 27.1 24.8 24.8 NaN 23.5 NaN 24.8 52 92 0 0 226 {'1,010' } 0 NaN 0 0 0 01/01/2022 01:50 27.1 24.8 24.8 NaN 23.3 NaN 24.8 52 91 0.5 0.1 226 {'1,009.80'} 0 NaN 0 0 0 01/01/2022 02:00 27.1 24.8 24.8 NaN 23.3 NaN 24.8 52 91 0 0 226 {'1,009.80'} 0 NaN 0 0 0 01/01/2022 02:10 27.1 24.8 24.8 NaN 23.3 NaN 24.8 52 91 0.5 0.5 226 {'1,009.80'} 0 NaN 0 0 0 01/01/2022 02:20 27.1 24.7 24.7 NaN 23.2 NaN 24.7 52 91 0.5 0.5 225 {'1,009.80'} 0 NaN 0 0 0 01/01/2022 02:30 27 24.7 24.7 NaN 23.2 NaN 24.7 52 91 0.5 0.2 226 {'1,009.80'} 0 NaN 0 0 0 01/01/2022 02:40 27 24.6 24.6 NaN 23.1 NaN 24.6 52 91 0 0 226 {'1,009.90'} 0 NaN 0 0 0
dt = D.Date_Asia_Jakarta_
dt = 4259×1 datetime array
01/01/2022 00:00 01/01/2022 00:10 01/01/2022 00:20 01/01/2022 00:30 01/01/2022 00:40 01/01/2022 00:50 01/01/2022 01:00 01/01/2022 01:10 01/01/2022 01:20 01/01/2022 01:40 01/01/2022 01:50 01/01/2022 02:00 01/01/2022 02:10 01/01/2022 02:20 01/01/2022 02:30 01/01/2022 02:40 01/01/2022 02:50 01/01/2022 03:00 01/01/2022 03:10 01/01/2022 03:20 01/01/2022 03:30 01/01/2022 03:40 01/01/2022 03:50 01/01/2022 04:00 01/01/2022 04:10 01/01/2022 04:20 01/01/2022 04:30 01/01/2022 04:40 01/01/2022 04:50 01/01/2022 05:00
jd = juliandate(dt)
jd = 4259×1
1.0e+06 * 2.4596 2.4596 2.4596 2.4596 2.4596 2.4596 2.4596 2.4596 2.4596 2.4596

4 Comments
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adhi dermawan
adhi dermawan on 28 Dec 2022
Hello sir, It worked on julian date but tried to convert it to modified julian date but I got this error
Error using mjuliandate (line 78)
Expected input to be one of these types:
double, single, uint8, uint16, uint32, uint64, int8, int16, int32, int64
Instead its type was datetime.
Error in csvcoba (line 28)
mjd = mjuliandate(dt);
VBBV
VBBV on 28 Dec 2022
use the below
mjd = mjuliandate(jd);
in place of
mjd = mjuliandate(dt);
adhi dermawan
adhi dermawan on 28 Dec 2022
I got another error sir
Error using mjuliandate (line 94)
Input must be an M-by-6 or M-by-3 matrix containing M full or partial date vectors, a date string and the format for the
date string, or three or six separate numeric arrays of the same size.
Error in csvcoba (line 29)
mjd = mjuliandate(jd);
adhi dermawan
adhi dermawan on 28 Dec 2022
I solved it in another way. thank you for helping me sir

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adhi dermawan
adhi dermawan
on 28 Dec 2022

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adhi dermawan
adhi dermawan
on 28 Dec 2022

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