# MATLAB Practice questions solution

211 views (last 30 days)
Ali Awada on 3 Jan 2021
Answered: Abhiram Rayidi on 27 Jun 2022
Hello all,
I am new to MATLAB and I am still trying to learn it by myself. I was trying to solve the questions posted by MATLAB. I know I didn't use the double function as suggested so please enlighten me with your ideas and let me know if i was at least close to what the problem is asking for:
The provided text file (readings.txt) contains a timestamp broken up into year, month, day, hour, minute, second, and timezone components, as well as a reading from a sensor. Write a script that reads the data from the file using the textscan function.
The script must:
• Convert the timestamps into single numeric serial date numbers stored in a variable named dates
• Ignore the timezone component of the timestamp by not reading it into the workspace
• Place numeric values for the readings in a single array of type double with a variable name of readings
clc
clear all
dates = textscan(fileID1, '%s %s %s %s %s %s %s %s');
fclose(fileID1);
whos dates;
celldisp(dates)
C=textscan(fileID2, '%q %q %q %q %q %q %*q %q');
fclose(fileID2);
whos C;
celldisp(C)
D=textscan(fileID3,'%*q %*q %*q %*q %*q %*q %*q %q');
fclose(fileID3);
whos D;
celldisp(D)

Image Analyst on 3 Jan 2021
Perhaps datenum()?
>> d=datenum(now)
d =
738159.473416505
Ali Awada on 11 Jan 2021
the problem asks us to use the function textscan

Kazem Gheysari on 24 Aug 2021
Edited: Kazem Gheysari on 24 Aug 2021
clear
C_text = textscan(fileID,'%s',8,'Delimiter',' ');
C = textscan(fileID,'%f %f %f %f %f %f EST %f','Delimiter',' ','EmptyValue',-Inf);
fclose(fileID);
Y = C{1,1};
M = C{1,2};
D = C{1,3};
H = C{1,4};
MN= C{1,5};
S = C{1,6};
dates = datenum(Y,M,D,H,MN,S)
Image Analyst on 24 Aug 2021
What is matlab1.com? (I did not click your link because there is no explanation)

Abhiram Rayidi on 27 Jun 2022
syms y(t);
dsolve(diff(y)==y, y(0)==1, 'Expansion Point', 0)

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