Is there such a table units identification approach?

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Leon 2020-10-21

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评论： Leon 2020-10-21

采纳的回答： Steven Lord

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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!

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Answer 1

Steven Lord 2020-10-21

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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.

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Leon 2020-10-21

Many thanks!

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

units{names == "Age"}

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Answer 2

drummer 2020-10-21

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Try this:

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

Cheers.

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drummer 2020-10-21

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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