Undefined function 'log' for input arguments of type 'table'.

I'm trying to import Excel sheets into Matlab and then performing log function on them but always get "Undefined function 'log' for input arguments of type 'table'.". Its a fresh install of Matlab and I have just started working with the software.

So, I have two sheets which I just renamed to X and Price and then type the following: Ln_P=log(Price);

And I also tried with the other one Ln_X=log(X);

Still same errors.

[Adam]

Your data is in a table object. As the error says, the log function does not accept 'table' types. If your data is purely numeric then just load it into a regular array. Otherwise look at

https://uk.mathworks.com/help/matlab/tables.html

and the section on 'Applying Functions to Table Contents'

[Erik Öhrner]

Yes, the problem was that I needed the Excel data to be in Numeric format and when I changed that it worked. Thanks for answering.

Answer 1

[Eng. Fredius Magige]

Hi try: log10 it should work

[Erik Öhrner]

Thanks for answering so quick, but same outcome however.

Answer 2

[Eng. Fredius Magige]

Hi Why not try: Ln_P=log10(Price);

Ln_X=log10(X);

Answer 3

[Steven Lord]

Tables can contain data of any type. Operate on just the variable(s) that contain numeric data. There are several ways to do this:

% Sample table
T = table(categorical({'M';'F';'M'}),[45;32;34],...
    {'NY';'CA';'MA'},logical([1;0;0]),...
    'VariableNames',{'Gender' 'Age' 'State' 'Vote'})

% Extract the variable by name
meanAge = mean(T.Age);

% Extract the variable by variable number
didAllVote = all(T{:, 4}) % the Vote variable

% Extract the variable by type
oldest = max(T{:, vartype('double')})

For more techniques you can use to work with data in a table, see the "Access Data in a Table" and "Calculations on Tables" section of the documentation for table.

Personally, where possibly I try to use the syntax involving the name of the variable -- that's independent of the order of the variables in the table and usually the most self-documenting option. When you see meanAge = mean(T.Age); in a block of code, you can understand the purpose of that code pretty quickly.