open large csv file

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asad ali 2019-8-29

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评论： Nicolas B. 2019-8-29

i have a csv file with 93 coloums and 150000 rows

number of coloums may change to 90 in some tests and all entries are text / string

i need a single code to calculate the no of rows and couloums dynamically by reading the csv file and then get the 93/90 variable data in seprate variables

i have been using uiimport in my GUI but when i compiled the code into an application (.exe) using matlab application compiler uiimport function gives following error

"Error using uiimport>showLargeFileWindow (line 1126)

Java exception occurred:

java.lang.NullPointerException

at com.mathworks.mlwidgets.importtool.TextImportClient.showWaitProgressWindow(TextImportClient.java:253)"

Now i am using

fid=fopen('1.csv');

>> data = textscan(fid,'%s','HeaderLines',0,'Delimiter',',','CollectOutput',1);

now i am getting all the data in i single variable data

can any body help me for opening this csv file in standalone application with each variable having its values stored

First row are the variable names

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Answer 1

Nicolas B. 2019-8-29

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在 MATLAB Online 中打开

Hi Asad,

have you considered using readcell or readtable depending of what you need for data type? You can configure it to define the delimiters. For example:

T = readtable(filename, 'Delimiter',';');

Regards

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asad ali 2019-8-29

i am receiving this error while using readtable

Tbl = readtable('1.csv', 'delimiter', ';', 'headerlines', 0, 'readvariablenames', true);

Error using table/readTextFile (line 237)

Cannot interpret data in the file '1.csv'. Found 92 variable names but 93 data columns. You

may need to specify a different format string, delimiter, or number of header lines.

Error in table.readFromFile (line 33)

t = table.readTextFile(filename,otherArgs);

Error in readtable (line 118)

t = table.readFromFile(filename,varargin);

Nicolas B. 2019-8-29

I would say that you have 1 header missing. Try to open your csv-file in libreoffice or excel and check whether there are headers to each column. If you cannot correct that, read the file without headers.

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