How can I clear an entire table column without deleting the variable?

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s.h.m_89 2018년 5월 23일
댓글: s.h.m_89 2018년 6월 13일
I have the following table and want to clear the variable P without deleting the variable. Is there a way how I can do that or should I just delete the variable by using removevars and add new data by 'new' variable P.
P Type Date
0,43008 'Feeder' '21.05.2018'
0,03786 'Feeder' '21.05.2018'
0,37238 'Loader' '21.05.2018'
(288x4 table)
Thanks in advance!
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Stephen23 2018년 5월 23일
@s.h.m_89: what do "cleared" numeric values look like? What value/s would they have?

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채택된 답변

Peter Perkins
Peter Perkins 2018년 6월 4일
The short answer is to just overwrite the entire variable:
t.P = NaN(size(T.P))
You could also overwrite every element
t.P(:) = NaN
but there's not much advantage. In recent versions of MATLAB, you can assign missing:
t.P(:) = missing
but if you know the var is numeric, NaN is just as good. But missing works on other data types too, like categorical, datetime, ... . If you need to clear out variables of different types, using missing avoids a switch on the type.
By the way, you should consider making Type a categorical, and making Date a datetime. You may have already done that.

추가 답변(1개)

sloppydisk 2018년 5월 23일
You can simply overwrite the values by indexing with curly braces if that is what you want
t = table(rand(6, 1), rand(6, 1), rand(6, 1))
t{:, 1} = (1:6)';
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Walter Roberson
Walter Roberson 2018년 5월 28일
NaN is the indicator of Missing for numeric entries for the purposes of tables.

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