how to read a really large lines of data(ascii file format) to a table

i have a really large ascii file that contains about 23,46,503 number of lines. i need to read them to a table with data types of each column as only text and number. i tried to import them using import data tool but it is taking forever to scan and parse the data (im using matlab 2019a). can anyone suggest me a faster approach to read the file to a table please. i even tried codes such as readtable(), dlmread(), fopen, fscanf etc. nothing works and it is throwing error.

it would be of great help if anyone helps

[KSSV]

Did you try textscan?

[Padmamalini T H]

my data contains a mixture of text and numeric values.

here is the sample of my data

0.2120 1 CF00203x Rx d 8 00 00 00 FF FF 00 00 FF

0.2170 1 18FF2303x Rx d 8 66 01 05 00 FF FF FF FF

0.3020 1 CF00203x Rx d 8 00 00 00 FF FF 00 00 FF

0.3070 1 18FF0803x Rx d 8 83 0D FF 00 05 00 00 FF

[Mohammad Sami]

Yes with textscan, you need to specify the format spec. for the column that is mixed, import it as char.

[Padmamalini T H]

Can i have the code to read an ascii file. Because When i give .asc it is showing error, when i give .txt or .dat(since the data is in a notepad) it shows error

[Allen]

Does the start of the data in your .txt file contain any header lines or does it explicitly contain data in the format you have provided? Also, is this data tab-delimited?

[Padmamalini T H]

It has got headers. The datas are space seperated

Answer 1

[Walter Roberson]

filename = 'YourFile.txt':
[fid, msg] = fopen(filename);
if fid < 0
    error('Failed to open file "%s" because "%s"', filename, msg);
end

%0.2120 1   CF00203x  Rx   d 8 00 00 00 FF FF 00 00 FF
fmt = ['%f%f%s%s', repmat('%x', 1, 10)];

datacell = textscan(fid, fmt, 'CollectOutput', true);
fclose(fid);

numeric_vals = [datacell{1}, datacell(3})];
text_vals = datacell{2};

[Padmamalini T H]

the file is an asc file sir. when i give the filename with .txt extension it is showing error no such file or directory found. and matlab doesnt allow .asc extension too. im new to matlab and i dont know much about it

[Walter Roberson]

filename = 'YourFile.asc':

MATLAB is happy to use fopen() to open a .asc file, as long as the file exists in the named location, or somewhere along the MATLAB path, and you have permission to access the file.

If the file is not in your current directory where you run the code, then you should assign the fully qualified name to filename such as

filename = 'C:\Users\TPad\Documents\MATLAB\Project13b\MyBigFile.asc';

[Padmamalini T H]

thanks now i have called the asc file into the matlab environment. but i wanted the ascii file in a table in the workspace.

[Kavya Vuriti]

You can try using importdata function to obtain structure containing data field and then use table function to convert it into table. As the file contains 23,46,503 number of lines, it takes around 1.66 seconds for importing.

[Walter Roberson]

i wanted the ascii file in a table in the workspace.

And what format is the table to be in?

You can use

array2table(numeric_vals)

and you can add in variables from text_vals{:,1} and text_vals{:,2} if you want a table() object.