How do I plot timeseries, including event like earthquake?

Hello

I have two files and their sizes are not same. Files consist of two columns such as date and value.

Date format is ISO 8601 such as 2019-12-30T01:15:14

Value format is float-number.

How do I plot time series to see details?

Regards...

Answer 1

[Sulaymon Eshkabilov]

Hi,

In this case, use one of these data import options:

(1) data import using uiimport('DATA_file_name.txt') that creates a table variable containing two column of data, viz date and values

(2) data import using importdata('DATA_file_name.txt') that creates structure type of data containing dates and data values.

(3) data import: textscan() ==> FID= fopen('DATA_file_name.txt'); DATA = textscan(FID, '%s %f'); fclose(FID);

The dates can be read with the command datenum(), e.g.,: DD = datenum('2019-12-30T01:15:14', 'yyyy-mm-ddTHH:MM:SSZ')

To plot the imported dates and data values: plot(DD, Values)

xlabels of dates can be displayed with datetick()

Good luck.

[Umay Ana]

Thank you for your guide. I try to apply the steps but I cannot read text file using textscan.

fileID = fopen('filename.txt');
C = textscan(fileID, '%{yyyy-MM-ddTHH:mm:ss}D %f', 'Delimiter', ' ');
fcloseID;

Answer 2

[Sulaymon Eshkabilov]

Here is corrected code:

fileID = fopen('filename.txt', 'r');

C = textscan(fileID, '%s %f'); % Presumably your file does not have headerlines (texts, etc). It contains only two columns

fclose(fileID);

[Umay Ana]

I don't understand why

% {...}D

doesn't work.

Why did you suggest using datenum? I don't want to see x-axes such as serial date number.

fileID = fopen('filename.txt', 'r');
C = textscan(fileID, '%s %f');  
fclose(fileID);
formatIn= 'yyyy-mm-ddTHH:MM:SS';
date = datenum(C{1,1},formatIn);
value = C{1,2};
% Class of date and value are double now.
plot(date,value)

y-axes is normal, not x-axes. Which date, month, day, hour, minute etc.?