How to read text header data from a csv file along with numerical data

My test.csv file is as follows:test.csv. I would like to read header for each column and numerical data as well.

My MATLAB program is

fid='BLM\test.csv'; delimiterIn = ',';% ',' seperated data
headerlinesIn = 1;%  Ignore 1st header line 
A = importdata(fid,delimiterIn,headerlinesIn);
t=A.data(:,2);a=A.data(:,4);
figure; plot(t,a) 

How to read the header test and use it later as title to my plot?

Answer 1

[Cris LaPierre]

Use readtable with VariableNamingRule set to true. Then extract the data you need from the table.

T = readtable('test.csv',"VariableNamingRule","preserve")

T = 7×7 table
    point     time      B:IRMCHG     B:IRML01     B:IRMS01     B:IRML02     B:IRMS02 
    _____    _______    _________    _________    _________    _________    _________

      1            0      -10.212     0.014042     0.015095     0.015813     0.018463
      2        8e-05    -0.024943     0.012861     0.013613     0.014188     0.016395
      3      0.00016    -0.019955     0.011599     0.012088     0.012405     0.014114
      4      0.00024    -0.019955     0.010515     0.010846     0.011015     0.012214
      5      0.00032    -0.019955     0.009731    0.0099341    0.0099856      0.01079
      6       0.0004    -0.024943    0.0091936     0.009289     0.009289    0.0098321
      7      0.00048    -0.019955    0.0088214    0.0088671    0.0088214    0.0092412

hdrs = T.Properties.VariableNames

hdrs = 1×7 cell array
    {'point'}    {'time'}    {'B:IRMCHG'}    {'B:IRML01'}    {'B:IRMS01'}    {'B:IRML02'}    {'B:IRMS02'}

plot(T.time,T.('B:IRMCHG'))
title(hdrs{3})

Answer 2

[FB]

Thanks a lot! Cris's answer did not resolve my problem fully. However, a variation of his approach solved the problem. The Matlab program below works for me for a multi-column csv file with first row header for each column and the rest being numerical data:

clc; clear all; close
fid='BLM\cbhat_blmdata_67678.csv'
fid='BLM\test.csv'
%Import the options of the csv file
opts=detectImportOptions(fid);
%Defines the row location of channel variable name
opts.VariableNamesLine = 1;
%Specifies that the data is comma seperated
opts.Delimiter =','; %Specifies that the data is comma seperated
%Read the table
T = readtable(fid,opts, 'ReadVariableNames', true);
% figure; plot(T.time,T.B_IRMCHG)
hdrs = T.Properties.VariableNames;
figure; plot(T.(hdrs{2}),T.(hdrs{3}))
title(hdrs{3})

[Rik]

A few remarks:

• clear all is equivalent to restarting Matlab. You probably don't need that. Using clear or clearvars instead is generally enough
• if you don't dump everything to the command window by skipping the ; symbols, you can make deliberate choices about which variables to print. That would also remove the need for clc.
• your use of fid as a variable name is confusing. Generally people use that for the file identifier, which is a handle to a file and is generated with fopen.
• you also didn't format your code as code. https://www.mathworks.com/matlabcentral/answers/help/rtc#rtc_summary

[Walter Roberson]

figure; plot(T.(hdrs{2}),T.(hdrs{3}))

could be

figure; plot(T{:,2},T{:,3})