matlab-import-export-data

Use readtable with detectImportOptions to control delimiters, encodings, and variable types. Set TextType to "string" and TreatAsMissing at read time to handle text and missing values correctly without post-import cleanup.

European CSVs use semicolons as delimiters because commas serve as decimal separators. Set Delimiter to ";", DecimalSeparator to ",", and Encoding to "UTF-8" in detectImportOptions before calling readtable.

Excel writes Inf and -Inf as 65535, and complex numbers become NaN because Excel cannot store them. Check imported columns for exactly 65535 or entirely NaN values to detect this silent corruption.

parquetread promotes integer columns containing nulls to double, which silently loses precision for int64 and uint64 values above 2^53. Use parquetDatastore with ReadSize set to "file" and readall to preserve integer types.

Pass the URL directly to readtable and specify FileType explicitly since MATLAB cannot infer the format from API endpoints. For authenticated endpoints, configure weboptions with header fields and pass them via detectImportOptions.

Avoid readtable for files too large for memory, where tall arrays or datastores fit better, and for database access via ODBC/JDBC. It also does not cover vehicle log formats, medical imaging formats, or streaming data acquisition.