Is there such a table units identification approach?

Imagine I have a table T1. We know its units will be

Units = T1.Properties.VariableUnits;

Similarly, its header will be

Headers = T1.Properties.VariableNames;

If I know the location of the VariableName, I can find its units easily. For example, if I know Header #35 is "dissolved_oxygen", I can find its unit easily as Units{35}. The thing is that sometimes I may not know the location of the VariableName. The only thing I know is its variableName Is there a similar approach like the Table values?

Column = T1.dissolved_oxygen;

I tried the below and it did not work:

Unit = Units.dissolved_oxygen;

Many thanks!

Answer 1

[Steven Lord]

Let's make a sample table and give it some units:

>> load patients
>> patients = table(LastName,Gender,Age);
>> patients.Properties.VariableUnits{1} = 'person';
>> patients.Properties.VariableUnits{2} = 'N/A';
>> patients.Properties.VariableUnits{3} = 'years';

Extract the variable names and units from the table:

>> names = patients.Properties.VariableNames;
>> units = patients.Properties.VariableUnits;

Get the units associated with the variable named Age:

>> units(names == "Age")

If you have multiple variable names, use ismember with two outputs to determine which element of the names array corresponds to the variable names you seek.

[Leon]

Many thanks!

This is what I'm looking for. I find curly parenthesis works even better.

units{names == "Age"}

Answer 2

[drummer]

Try this:

opts = detectImportOptions('yourXLfile.xlsx')
opts.selectedVariableNames = {'dissolved_oxygen'};
T1 = readtable('yourXLfile.xlsx', opts);
summary(T1)

Cheers.

[Leon]

Many thanks! I can find its index number from a search of the Units string array as well, but I really hope there is an easier way to do this, because I have a lot of variables and I need to be able to call its units easily.

[drummer]

Can you share a sample of your table where you can get 'dissolved_oxygen' and Unit{35}?

[drummer]

I made a different approach from Stephen's, using the same example.

His approach is more dynamic, though. I walked through all the headers.

T = readtable('patients.dat');
headers = T.Properties.VariableNames

for i = 1 : numel(headers)
    if strcmp(headers(i), 'Gender') == 1 % if the header is your variable of interest
    i % you could replace here by your Unit{i}, for example.
    end
end

[Leon]

Many thanks for sharing!