Problem plotting with 4 columns

Hi all, I am trying to plot this function, but getting so many errors. I first got this error: "A numeric or double convertible argument is expected" So I converted the table to array, then I got this error: "Size mismatch in Param Cell / Value Cell pair" I ran out of ideas ! Basically, I need x to be the dates (using standard formats, all days showing) y to show 3 columns: min, max and difference between them Here is my code, I have also attached the data file. Any help would be highly appreciated ! Thanks a lot!

clear
clc

Table_Q7=readtable('Test_data7.csv');
x_tbl=Table_Q7(6:end,2);
%tbl 2 array
x=table2array(x_tbl);

%ymin tbl2array
y_min_tbl=Table_Q7(6:end,3);
y_min=table2array(y_min_tbl);

%ymax tbl2array
y_max_tbl=Table_Q7(6:end,4);
y_max=table2array(y_max_tbl);

%y difference between max and min
y_diff_tbl=Table_Q7(6:end,5);
y_diff=table2array(y_diff_tbl);

%y=table2array(y_tbl)
plot(x,[y_max,y_min,y_diff])

Answer 1

[jonas]

Here's a solution using textscan instead of readtable

fid=fopen('Test_data7.csv')
formatSpec='%s%d%d%d';
out=textscan(fid,formatSpec,...
    'delimiter',',',...
    'MultipleDelimsAsOne',true,...
    'collectoutput',true,...
    'HeaderLines',6)
fclose(fid);

t=datetime(out{1});
data=out{2};
plot(t,data)

[D.J]

Perfect ! Thanks a million ...Much appreciated !!

[jonas]

No problem, happy to help!

Answer 2

[jonas]

The problem is with your data import, as the csv is a bit messy. This is the cleanest import out of many attempts. Results attached.

opts=detectImportOptions('Test_data7.csv','Delimiter',',','NumHeaderLines',5)
opts.ExtraColumnsRule='ignore'
opts.SelectedVariableNames={'Date','MinTemp','MaxTemp','DiffTemp'}
T=readtable('Test_data7.csv',opts);
TT=table2timetable(T);
plot(TT.Date,TT.Variables)

[D.J]

I am getting this error: Undefined function or variable 'detectImportOptions'

[D.J]

I am afraid still not working. Getting the same error ..

[D.J]

Is it actually working at your end?

[jonas]

What MATLAB release are you using? Can you paste the first rows of the output of readtable, assuming that you are able to use detectImportOptions? It's working fine on my end yep.

[D.J]

I am using Matlab R2015b I have never used deteImportOptions. I tried to find details about it in the documentation, but there is nothing there !

[jonas]

https://se.mathworks.com/help/matlab/ref/detectimportoptions.html

Introduced in R2016b

A few options:

• Maybe we can solve it without a clean import. Can you copy-paste the first rows of your readtable output?
• Update your MATLAB release
• We can use csvread or textscan instead.

[D.J]

This is what I am getting:

Undefined function or variable 'detectImportOptions'.
Error in plot_7_T (line 24)
opts=detectImportOptions('Test_data7.csv','Delimiter',',','NumHeaderLines',5) 
>>

[jonas]

Well, I mean in your original code. Output of this:

Table_Q7=readtable('Test_data7.csv');

Only copy first 2-3 rows, or this comment chain becomes hard to read.

[D.J]

Is this what you need? if you can't read it, I attached a snapshot of it:

'ttt'  ''  ''  ''  ''  NaN  NaN  NaN  NaN  NaN
'ttt'  ''  ''  ''  ''  NaN  NaN  NaN  NaN  NaN
'ttt'  ''  ''  ''  ''  NaN  NaN  NaN  NaN  NaN
''  ''  ''  ''  ''  NaN  NaN  NaN  NaN  NaN
''  'Date'  'MinTemp'  'MaxTemp'  'DiffTemp'  NaN  NaN  NaN  NaN  NaN
''  '1/07/2017'  '2.2'  '19.7'  '17.5'  NaN  NaN  NaN  NaN  NaN
''  '2/07/2017'  '2'  '21'  '19'  NaN  NaN  NaN  NaN  NaN
''  '3/07/2017'  '4.9'  '21.4'  '16.5'  NaN  NaN  NaN  NaN  NaN
''  '4/07/2017'  '9.5'  '25.3'  '15.8'  NaN  NaN  NaN  NaN  NaN
''  '5/07/2017'  '8.6'  '25'  '16.4'  NaN  NaN  NaN  NaN  NaN
''  '6/07/2017'  '5.5'  '21.8'  '16.3'  NaN  NaN  NaN  NaN  NaN
''  '7/07/2017'  '9.5'  '18.9'  '9.4'  NaN  NaN  NaN  NaN  NaN

[D.J]

I don't want to take the risk of updating my matlab. I am worried the software might be stuffed up completely. It is the student version from the university, and if I get an technical problems due to the update, I won't be able to get any help during the weekend.

[jonas]

Thanks. That output is not very useful. I'll come back with another solution shortly.

[jonas]

Posted a separate answer using textscan. I understand your concern. I used release 2013a for 3-4 years until I was finally forced to update as I needed to use the latest image processing functions. I saved the old release just-in-case, but I have never had to use it :)

Answer 3

[D.J]

Thanks a lot Jonas. I really appreciate your help !

[jonas]

If any one of the answers solved your problem please accept it ;)