Unable to plot column of data that is not numerical ("Input arguments must be numeric, datetime or duration.")

I've been using this car evaluation dataset and I am wanting to create a bar graph of only ONE column.

I've been able to successfully sort the data into tables by renaming the 'car.data' file to 'car.data'txt' and using 'readtables' to import the data.

I've also isolated each column into their own variables so I can try and create graphs with them.

However I keep getting the "Input arguments must be numeric, datetime or duration." error.

steps:

 x = readtable('car.data.txt');
 x.Properties.VariableNames = {'buying_price' 'maintanence_price' 'doors' 'persons' 'boot_size' 'safety_level' 'acceptability'}

 buying = x(:,1)

 bar(buying);
 Error using bar (line 98)
 Input arguments must be numeric, datetime or duration.

Where have I gone wrong?

Thanks

Answer 1

[Peter Perkins]

It looks like that variable is categorical, but has been read in as text. You probably want to convert to a categorical variable and use histogram.

Answer 2

[Walter Roberson]

buying = x.buying_price;

or

buying = x{:,1};

[mustard26]

I'm still getting the same error

"Input arguments must be numeric"

[Walter Roberson]

Please show

class(x.buying_price)

[mustard26]

ans =

 cell

[Walter Roberson]

I suspect that your first column has some text in part of it and was read in as characters