How to extract strings from a table?
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Alex Gimeno
il 2 Ott 2019
Commentato: Simon Schmidt
il 29 Apr 2021
Hi all,
I know this is likely a very basic question, but I can't seem to figure it out. I want to extract strings from a table and put them in their own array. My code is here:
IDs=1718; %Define how many IDS there are in the total table; this was determined from the Excel sheet
masterCountSheet = readtable('Tasks_Count_060118 (streamlined).xlsx'); %Create table containing master count sheet data
IDDataArray=zeros(1,IDs)
for i=1:IDs
IDDataArray(i)=masterCountSheet(i,1)
end
However, whenever I reference a specific cell in the table, I get a cell array returned, not a string. Any ideas as to why and how to fix this?
2 Commenti
David K.
il 2 Ott 2019
If IDDaraArray at the end is a cell array of strings then you should be able to just do
output = string(IDDataArray)
Risposta accettata
Guillaume
il 2 Ott 2019
Modificato: Guillaume
il 2 Ott 2019
Why is the size of the array hardcoded (which means the code will break if something change with the file) instead of just asking matlab for it?
In any case, the loop is completely unnecessary:
IDDataArray = masterCountSheet.(1);
%or
IDDataArray = masterCountSheet{:, 1};
%or
IDDataArray = masterCountSheet.NameOf1stVariableInTable;
Note that
masterCountSheet(i,1)
returns a table (not a cell array) which consist of just the ith row and first variable of masterCountSheet. To access the content of a table you use {} indexing or . indexing, not ().
Also note that if that first variable indeed contain strings, then initialising the array with zeros is an error. zeros creates a numerical array, not a string array.
Più risposte (1)
Anthony Dave
il 27 Nov 2020
Modificato: Anthony Dave
il 27 Nov 2020
@David K and @Walter Roberson's answers enlightened me. You can use the following code in this example.
IDDataArray = string(masterCountSheet{1:IDs,1});
If you just want to read data in all rows, try:
IDDataArray = string(masterCountSheet{:,1});
1 Commento
Simon Schmidt
il 29 Apr 2021
Hi! What if only want the first 3 characters (instead of the whole string) of every row?
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