Why is ReadTable Deleting Data with NaN?

Question

Alan Lee 2022-8-12

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评论： Alan Lee 2022-8-12

I'm trying to automate the reading of several hundred excel files with identical layouts using a for loop and readtable.

Does anyone know why readtable is removing data in only SOME of my columns and replacing them with NaN? I'm a bit of an amateur, so I would appreciate any help.

Excel Spreadsheet

Matlab Line

teeth = readtable(file,'Sheet','Teeth Form Sheet','Range',''); %This reads the excel file and a particular sheet and should import all the data

Table Output

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Cris LaPierre 2022-8-12

Please attach your file using the paperclip icon.

Alan Lee 2022-8-12

Sorry to waste your time Cris.

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Answer 1

Alan Lee 2022-8-12

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I figured it out. The issue was that not all my data points were the same Data type and that Readtable was getting confused. Once I converted all the data to Characters there were no more issues,

opts = detectImportOptions(file,'Sheet','Teeth Form Sheet','Range','');

opts = setvartype(opts,'char');

teeth = readtable(file,opts);

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Answer 2

Cris LaPierre 2022-8-12

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The columns of a table must all be of the same datatype. readtable has set the datatype for each column based on the datatype in the first row. When the datatype is set to numeric and non-numeric information is encountered, it is replaced with NaN, meaning "not a number".

It looks to me like the data you want to read in is actually in rows 2-4 and 7-9. You can use the import tool to interactive create your import, or the options field of readtable.