How to extract coordinate from the header files?

Hi everyone.

I have 6 headerlines and then data. I want to extract the only the coordinate numbers in the first headerline.

Example data as below and also as attached

Lat: 6.4931, Lon: 99.6067, Parameter: z(m)

Depth (m): 22.45

Constituents included: m2 s2 k1 o1

Time start: 00:00, 1. 1.1993

Time step (min): 60.00

Time Series length (hours):236664

01-Jan-1993 00:00:00 -0.0946

01-Jan-1993 01:00:00 -0.3369

01-Jan-1993 02:00:00 -0.5110

01-Jan-1993 03:00:00 -0.5776

Please see the script below:

clc;clear all; close all;

delim = ' '; % space delimited
% delim = '\t'; % tab delimited
% delim = ','; % comma delimited

%Input File
fid=fopen('aa__file002.txt');
% A = textscan(fid,'%s %n','Delimiter',delim); % read file;
A = textscan(fid,'%s %s %f','HeaderLines',6); % read file;
Headerlin1 = textscan(fid,'%s     %f%s %s    %f%s %s %s',1,'Delimiter','delim');
fclose(fid); % close file

Any help regarding the problem are really appreciated.

Answer 1

[Cris LaPierre]

Think of fid as a pointer that tells textscan where to read from. It moves its way byte by byte through the file until it reaches the end. When you call textscan for Headerlin1, it's at the end of the file. Your option, then, is to either read in Headerlin1 first, and then continue with reading in the rest of the file, or use frewind to bring fid back to the beginning of the file before reading in the first line.

You can get textscan to skip the text before a number by placing that text right before the format spec: Lat:%f

Option 1

fid=fopen('aa__file002.txt');
Headerlin1 = textscan(fid,'Lat:%f Lon:%f %*[^\n]','Delimiter',','); % extra bit reads to the end of the line
A = textscan(fid,'%s %s %f','HeaderLines',5); % read file;
fclose(fid);

Option 2

fid=fopen('aa__file002.txt');
A = textscan(fid,'%s %s %f','HeaderLines',6); % read file;
frewind(fid);
Headerlin1 = textscan(fid,'Lat:%f Lon:%f','Delimiter',',');
fclose(fid);

[Cris LaPierre]

For easier handling of dates and time, consider reading in the date as a datetime, and the time as a duration.

A = textscan(fid,'%{dd-MMM-yyyy}D %{hh:mm:ss}T %f','HeaderLines',5); % read file;

Read more about these datatypes here.

[hanif hamden]

Thank you very much and also thanks for sharing the information