MATLAB Practice questions solution
116 visualizaciones (últimos 30 días)
Mostrar comentarios más antiguos
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:
Problem(link: https://www.mathworks.com/services/training/certification/ml-professional-exam/practice-test.html)
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
fileID1 = fopen('readings.txt');
dates = textscan(fileID1, '%s %s %s %s %s %s %s %s');
fclose(fileID1);
whos dates;
celldisp(dates)
fileID2=fopen('readings.txt')
C=textscan(fileID2, '%q %q %q %q %q %q %*q %q');
fclose(fileID2);
whos C;
celldisp(C)
fileID3=fopen('readings.txt');
D=textscan(fileID3,'%*q %*q %*q %*q %*q %*q %*q %q');
fclose(fileID3);
whos D;
celldisp(D)
1 comentario
Respuestas (3)
Image Analyst
el 3 de En. de 2021
Perhaps datenum()?
>> d=datenum(now)
d =
738159.473416505
7 comentarios
Image Analyst
el 10 de En. de 2021
Then just use the first 3 lines and skip the rest of the lines that have to do with plotting.
Kazem Gheysari
el 24 de Ag. de 2021
Editada: Kazem Gheysari
el 24 de Ag. de 2021
clear
fileID = fopen('readings.txt');
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)
readings = C{1,7};
1 comentario
Image Analyst
el 24 de Ag. de 2021
What is matlab1.com? (I did not click your link because there is no explanation)
Abhiram Rayidi
el 27 de Jun. de 2022
syms y(t);
dsolve(diff(y)==y, y(0)==1, 'Expansion Point', 0)
1 comentario
Walter Roberson
el 16 de Jun. de 2023
syms y(t);
dsolve(diff(y)==y, y(0)==1, 'ExpansionPoint', 0)
Ver también
Categorías
Más información sobre Platform and License en Help Center y File Exchange.
Community Treasure Hunt
Find the treasures in MATLAB Central and discover how the community can help you!
Start Hunting!