plot csv with column names used automatically as x and y label

This is the data.

DateTime,Number

2024-11-18 03:37:01,0

2024-11-18 03:38:01,0

2024-11-18 03:39:01,200

2024-11-18 03:40:01,400

2024-11-18 03:41:01,600

2024-11-18 03:42:01,600

2024-11-18 03:43:01,800

2024-11-18 03:44:01,1000

2024-11-18 03:45:01,1200

This is the script.

data = readtable("results.csv","TextType","string");

plot(data.DateTime, data.Number);

I want to use DateTime for xlabel and Number for ylabel automatically.

Answer 1

[Walter Roberson]

data = readtable("results.csv","TextType","string");
plot(data, data.Properties.VariableNames(1), data.Properties.VariableNames(2));

[Igenyar]

Thanks, below is the error.

>> data.Properties.VariableNames(2)

ans =

1×1 cell array

{'Number'}

>> data.Properties.VariableNames(1)

ans =

1×1 cell array

{'DateTime'}

>> plot(data,data.Properties.VariableNames(1), data.Properties.VariableNames(2));

Error using tabular/plot

Too many input arguments.

[Walter Roberson]

data = readtable("results.csv","TextType","string");
plot(data, data.Properties.VariableNames{1}, data.Properties.VariableNames{2});

[Igenyar]

Sorry, I still see the same error.

>> data = readtable("results.csv","TextType","string");

plot(data, data.Properties.VariableNames{1}, data.Properties.VariableNames{2});

Error using tabular/plot

Too many input arguments.

>> data

data =

1439×2 table

DateTime Number

___________________ ______

2024-11-19 00:01:18 0

2024-11-19 00:02:18 133

2024-11-19 00:03:18 383

2024-11-19 00:04:18 511

2024-11-19 00:05:18 600

...

>> version

ans =

'9.7.0.1190202 (R2019b)'

[Walter Roberson]

Sigh, you should have mentioned earlier that you were using an old release.

data = readtable("results.csv","TextType","string");
plot(data{:,1}, data{:,2});
xlabel(data.Properties.VariableNames{1});
ylabel(data.Properties.VariableNames{2});

Answer 2

[Rahul]

Hi Igenyar,

I believe you want to plot the two columns ‘DateTime’ and ‘Number’ of the given csv file ‘results.csv’, while using ‘DateTime’ for ‘xlabel’ and ‘Number’ for ‘ylabel’ respectively in a plot.

Based on the sample data provided, I am able to reproduce this issue on MATLAB R2024b, and the given script provides the expected plots.

I used the given sample table for creating a local csv file, in order to verify the provided script. The axes labels have been specified as variables names in data file ‘results.csv’. Here’s how the output looks like:

• Generating sample csv file:

% Define the data 
DateTime = {'2024-11-18 03:37:01'; '2024-11-18 03:38:01'; '2024-11-18 03:39:01'; 
            '2024-11-18 03:40:01'; '2024-11-18 03:41:01'; '2024-11-18 03:42:01'; 
            '2024-11-18 03:43:01'; '2024-11-18 03:44:01'; '2024-11-18 03:45:01'}; 
Number = [0; 0; 200; 400; 600; 600; 800; 1000; 1200]; 
 
% Convert DateTime strings to datetime objects 
DateTime = datetime(DateTime, 'InputFormat', 'yyyy-MM-dd HH:mm:ss'); 
 
% Create the table 
dataTable = table(DateTime, Number); 
 
% Write the table to a CSV file 
writetable(dataTable, 'data.csv');

• Plotting column data on appropriate axes:

data = readtable("data.csv","TextType","string"); 
plot(data.DateTime, data.Number); 
xlabel(data.Properties.VariableNames{2}); 
ylabel(data.Properties.VariableNames{1}); 

To know more about the usage of ‘plot’ function, you can use the following command in MATLAB:

>> doc plot

Regards!