A reader for comma separated value (CSV) files with customizable delimiters and filters. The default delimiter is ',' and headers are included. Floating point values are stored as float32 unless double precision is enabled. More...

#include <inviwo/dataframe/io/csvreader.h>

Inheritance diagram for inviwo::CSVReader:

Public Types
enum class	EmptyField { Throw , EmptyOrZero , NanOrZero }

Public Member Functions
virtual CSVReader *	clone () const override

	CSVReader (const CSVReader &)=default

	CSVReader (CSVReader &&) noexcept=default

	CSVReader (std::string_view delimiters=defaultDelimiters, bool hasHeader=defaultFirstRowHeader, bool doublePrecision=defaultDoublePrecision)

const std::string &	getDelimiters () const

const csvfilters::Filters &	getFilters () const

EmptyField	getHandleEmptyFields () const

const std::string &	getLocale () const

size_t	getNumberOfExamplesRows () const

virtual std::any	getOption (std::string_view key) override

bool	getStripQuotes () const

const std::string &	getUnitRegexp () const

bool	hasDoublePrecision () const

bool	hasFirstColIndices () const

bool	hasFirstRowHeader () const

bool	hasUnitsInHeaders () const

CSVReader &	operator= (const CSVReader &)=default

CSVReader &	operator= (CSVReader &&) noexcept=default

virtual std::shared_ptr< DataFrame >	readData (const std::filesystem::path &fileName) override

std::shared_ptr< DataFrame >	readData (std::istream &stream) const

CSVReader &	setDelimiters (const std::string &delim)

CSVReader &	setEnableDoublePrecision (bool useDoublePrecision)

CSVReader &	setFilters (const csvfilters::Filters &filters)

CSVReader &	setFirstColIndices (bool hasIndices)

CSVReader &	setFirstRowHeader (bool hasHeader)

CSVReader &	setHandleEmptyFields (EmptyField emptyField)

CSVReader &	setLocale (std::string_view loc)

CSVReader &	setNumberOfExampleRows (size_t rows)

virtual bool	setOption (std::string_view key, std::any value) override

CSVReader &	setStripQuotes (bool stripQuotes)

CSVReader &	setUnitRegexp (std::string_view regexp)

CSVReader &	setUnitsInHeaders (bool unitInHeaders)

Public Member Functions inherited from inviwo::DataReaderType< DataFrame >
	DataReaderType (const DataReaderType &rhs)=default

	DataReaderType (DataReaderType &&rhs) noexcept=default

DataReaderType &	operator= (const DataReaderType &that)=default

DataReaderType &	operator= (DataReaderType &&that) noexcept=default

virtual std::shared_ptr< DataFrame >	readData (const std::filesystem::path &filePath, MetaDataOwner *)

Public Member Functions inherited from inviwo::DataReader
void	addExtension (FileExtension ext)

	DataReader (const DataReader &rhs)=default

	DataReader (DataReader &&rhs) noexcept=default

const std::vector< FileExtension > &	getExtensions () const

DataReader &	operator= (const DataReader &that)=default

DataReader &	operator= (DataReader &&that) noexcept=default

template<typename T >
bool	readsType () const

Static Public Attributes
static constexpr std::string_view	defaultDelimiters = ","

static constexpr bool	defaultDoublePrecision = false

static constexpr EmptyField	defaultEmptyField = EmptyField::NanOrZero

static constexpr bool	defaultFirstColIndices = false

static constexpr bool	defaultFirstRowHeader = true

static constexpr std::string_view	defaultLocale = "C"

static constexpr size_t	defaultNumberOfExampleRows = 50

static constexpr bool	defaultStripQuotes = true

static constexpr bool	defaultUnitInHeaders = true

static constexpr std::string_view	defaultUnitRegexp = R"((.)\[(.)\])"

Additional Inherited Members
Protected Member Functions inherited from inviwo::DataReaderType< DataFrame >
virtual bool	canRead (const std::type_index &index) const override

Static Protected Member Functions inherited from inviwo::DataReader
static void	checkExists (const std::filesystem::path &path)

static std::filesystem::path	downloadAndCacheIfUrl (const std::filesystem::path &url)

static std::ifstream	open (const std::filesystem::path &path, std::ios_base::openmode mode=std::ios_base::in)

static std::ifstream	openAndCacheIfUrl (const std::filesystem::path &path, std::ios_base::openmode mode=std::ios_base::in)

static std::string	readFileContents (const std::filesystem::path &path)

Protected Attributes inherited from inviwo::DataReader
std::vector< FileExtension >	extensions_

Detailed Description

A reader for comma separated value (CSV) files with customizable delimiters and filters. The default delimiter is ',' and headers are included. Floating point values are stored as float32 unless double precision is enabled.

Member Enumeration Documentation

◆ EmptyField

enum class inviwo::CSVReader::EmptyField

strong

How to handle missing / empty data

Enumerator
Throw	Throw a DataReaderException.
EmptyOrZero	"" for categorical and 0 for numerical values
NanOrZero	"" for categorical, NaN for floating point, and 0 for integer values

Member Function Documentation

◆ clone()

virtual CSVReader * inviwo::CSVReader::clone ( ) const

overridevirtual

Implements inviwo::DataReaderType< DataFrame >.

◆ getOption()

virtual std::any inviwo::CSVReader::getOption ( std::string_view key )

overridevirtual

Get any of the settings supported by the reader, supported keys:

Delimiters (string)
StripQuotes (bool)
FirstRowHeader (bool)
FirstColIndices (bool)
UnitsInHeaders (bool)
UnitRegexp (sting)
DoublePrecision (bool)
NumberOfExampleRows (size_t)
Locale (string)
HandleEmptyFields (EmptyField)
Filters (csvfilters::Filters)

Reimplemented from inviwo::DataReader.

◆ readData() [1/2]

virtual std::shared_ptr< DataFrame > inviwo::CSVReader::readData ( const std::filesystem::path & fileName )

overridevirtual

read a CSV file from a file

Parameters

fileName name of the input CSV file

Returns: a DataFrame containing the CSV data

Exceptions

FileException	if the file cannot be accessed
DataReaderException	if the file contains no data, the first row should hold column headers, but they cannot be found, or if there are unmatched quotes at the end of the file

Implements inviwo::DataReaderType< DataFrame >.

◆ readData() [2/2]

std::shared_ptr< DataFrame > inviwo::CSVReader::readData ( std::istream & stream ) const

read a CSV file from a input stream, e.g. a std::ifstream. In case file streams are used, the file must have be opened prior calling this function.

Parameters

stream input stream with the CSV data

Returns: a DataFrame containing the CSV data

Exceptions

DataReaderException if the given stream is in a bad state, the stream contains no data, the first row should hold column headers, but they cannot be found, or if there are unmatched quotes at the end of the stream

◆ setDelimiters()

CSVReader & inviwo::CSVReader::setDelimiters ( const std::string & delim )

See also: CSVReader::defaultDelimiters

◆ setEnableDoublePrecision()

CSVReader & inviwo::CSVReader::setEnableDoublePrecision ( bool useDoublePrecision )

Sets the precision for columns containing floating point values. If useDoublePrecision is true, values are stored as double (64 bits), otherwise float (32 bits) is used.