how to import csv file in matlab

10.413 visualizaciones (últimos 30 días)
Nur Zakaria
Nur Zakaria el 18 de Abr. de 2013
Comentada: Dyuman Joshi el 29 de Dic. de 2023
Hi, I have one question. I need to import data into MATLAB from a CSV file. Unfortunately, the data has header information in 3 columns.
How do I skip the headers and get the data directly?
For example:
a= import data ('C:\s11.dat') *
Then what is the next step? I need your help.
Thank you.
  4 comentarios
Pratik
Pratik el 29 de Dic. de 2023
Movida: Dyuman Joshi el 29 de Dic. de 2023
I have .csv, in which first column is in date format. second and third columns are integer values. how to read those columns and plot ?
Dyuman Joshi
Dyuman Joshi el 29 de Dic. de 2023
Use readtimetable and specify the 1st column as the date-time data.

Iniciar sesión para comentar.

Respuesta aceptada

Mukesh Jadhav
Mukesh Jadhav el 9 de Oct. de 2016
Editada: MathWorks Support Team el 15 de Mzo. de 2021
To import data from a CSV file into MATLAB use the “readtable” function. The “readtable” function automatically detects the header and the number of lines to skip.
T = readtable('myfile.csv');
Alternatively, you can specify the number of lines to skip using:
T = readtable('myfile.csv','NumHeaderLines',3); % skips the first three rows of data
For more information, see:
  2 comentarios
francisco caldeira
francisco caldeira el 4 de Mayo de 2020
Editada: francisco caldeira el 4 de Mayo de 2020
readtable('myfile.csv'); this generates a warning -> ' 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 'PreserveVariableNames' to true to use the original column headers as table variable names. '
To solve do:
T = readtable('myfile.csv','PreserveVariableNames',true);
Yongwon Jang
Yongwon Jang el 18 de Jul. de 2023
In ver 2023a, syntex changed like below:
T = readtable('myfile.csv', 'VariableNamingRule', 'preserve');

Iniciar sesión para comentar.

Más respuestas (3)

Karen Hornsby
Karen Hornsby el 18 de Abr. de 2013
HI, You can either use the import data wizard by right clicking on the file in the current folder window. When the import wizard opens it should give you a preview of the data and in the top right is a box which asks you how many header lines there are. You can use this to create code to open files of this type repeatedly (this works well but if your new to matlab it can be a bit confusing to edit) or you can used the following code to open files
ftoread = '%file name';
fid = fopen(ftoread);
fgetl(fid) %reads line but does nothing with it
fgetl(fid)
fgetl(fid)
M = textscan(fid, '%f', 'Delimiter','\,'); % you will need to change the number of values to match your file %f for numbers and %s for strings.
fclose (fid)
You can get more help with this in the help file, just type in the command you want help with in the search box. Karen

Thomas
Thomas el 18 de Abr. de 2013
Editada: Thomas el 18 de Abr. de 2013
I think the easiest way is to use CSVIMPORT from the File Exchange:
%read data example: Import columns as column vectors
[X Y Z] = csvimport('vectors.csv', 'columns', {'X, 'Y', 'Z'});
%remove headers
X(1) = [];
Y(1) = [];
Z(1) = [];
This assumes that the first element in the array contains the header
Thomas
  1 comentario
Thomas Carter
Thomas Carter el 6 de Jun. de 2022
Editada: Thomas Carter el 6 de Jun. de 2022
I have found that with large datasets, csvimport corrupts data. Spent a full day trying to figure this one out.

Iniciar sesión para comentar.


jgd0008
jgd0008 el 2 de Dic. de 2016
Editada: per isakson el 2 de Dic. de 2016
Hi, Something like this, may work;
data = fopen('file_name.csv');
A = textscan(data,'%s','Delimiter','\n');
B = A{1,1};
fclose(fid);
C = textscan(B,'%s','Delimiter',',');
D = C{1};

Categorías

Más información sobre Large Files and Big Data en Help Center y File Exchange.

Etiquetas

Aún no se han introducido etiquetas.

Community Treasure Hunt

Find the treasures in MATLAB Central and discover how the community can help you!

Start Hunting!

Translated by