Data Import and Export#

General data loading#

Note

loadd and saved are recommended for most cases when working with the following file types:

GAUSS, SAS, Stata and SPSS datasets.
CSV and Excel files with variable names in the first row.

getHeaders	Returns the variable names from a dataset as a string array.
loadd	Loads data into a GAUSS dataframe. The supported dataset types are CSV, Excel (XLS, XLSX), HDF5, GAUSS Matrix (FMT), GAUSS Dataset (DAT), Stata (DTA) and SAS (SAS7BDAT, SAS7BCAT).
saved	Writes a matrix or dataframe in memory to a dataset in a specified format.

CSV and delimited text files#

csvReadM	Reads numeric data from a CSV file into a GAUSS matrix.
csvReadSA	Reads data from a CSV file into a GAUSS string array.
csvWriteM	Write the contents of a GAUSS matrix to a CSV file.

Spreadsheets (Excel files)#

xlsGetSheetCount	Returns the number of sheets in an Excel® spreadsheet.
xlsGetSheetSize	Returns the size (rows and columns) of a specified sheet in an Excel® spreadsheet.
xlsGetSheetTypes	Gets the cell format types of a row in an Excel® spreadsheet.
xlsMakeRange	Builds an Excel® range string from a row/column pair.
xlsReadM	Reads from an Excel® spreadsheet into a GAUSS matrix.
xlsReadSA	Reads from an Excel® spreadsheet into a GAUSS string array.
xlsWrite	Writes a GAUSS matrix, string, or string array to an Excel® spreadsheet.

HDF 5 files#

h5create	Create a HDF5 dataset (.h5).
h5open	Open a HDF5 file.
h5read	Reads data from a HDF5 file (.h5) into a GAUSS matrix.
h5readAttribute	Read attributes from a HDF5 file into GAUSS.
h5write	Writes a GAUSS matrix to a HDF5 file.

GAUSS Data Sets#

These are the main functions to use for loading and saving GAUSS datasets.

loadd	Loads a data set into a GAUSS dataframe.
saved	Saves matrices or dataframes to a variety of dataset types.

The following functions use file handles which enable reading and writing partial chunks of a dataset.

close	Closes an open data set (.dat file).
closeall	Closes all open data sets.
datacreate	Creates a file handle to a new, empty GAUSS data set.
dataopen	Opens a file handle to a GAUSS data set.
eof	Tests for end of file.
getnr	Computes number of rows to read per iteration for a program that reads data from a disk file in a loop.
getnrmt	Computes number of rows to read per iteration for a program that reads data from a disk file in a loop.
readr	Reads rows from open data set.
seekr	Moves pointer to specified location in open data set.
tempname	Creates a temporary file with a unique name.
typef	Returns the element size (2, 4 or 8 bytes) of data in open data set.
writer	Writes matrix to a GAUSS dataset using open file handle.

Databases#

Database Setup#

dbAddDatabase	Adds a database to the list of database connections using the driver type or a connection URL.
dbGetDrivers	Returns a list of available database drivers.
dbIsDriverAvailable	Returns 1 if a specified database driver is available.
dbRemoveDatabase	Removes a database connection from the list of open database connections. Frees all related resources.

Database Properties#

dbGetConnectOptions	Returns the connection options string used for a database connection.
dbGetDatabaseName	Returns the name of the database.
dbGetDriverName	Returns the name of the connection’s database driver.
dbGetHostName	Returns the database connection’s host name.
dbGetPassword	Returns a connection’s password.
dbGetNumericalPrecPolicy	Returns the default numerical precision policy for a specified database connection.
dbGetPort	Returns the database connection’s port number if it has been set.
dbIsOpen	Reports whether a specified database connection is open.
dbIsValid	Reports whether a specified database connection has a valid driver.
dbSetConnectOptions	Sets database-specific options.
dbSetDatabaseName	Sets the connection’s database name to name.
dbSetHostName	Sets the specified database connection’s host name.
dbSetNumericalPrecPolicy	Sets the default numerical precision policy used by queries created on this database connection.
dbSetPassword	Sets the database connection’s password.
dbSetPort	Sets the specified database connection’s port number.

Database Information#

dbGetPrimaryIndex	Returns the primary index for the specified table.
dbGetTableHeaders	Returns a string array populated with the names of all the fields in a specified table (or view).
dbGetTables	Returns the database’s tables, system tables and views.
dbHasFeature	Returns a 1 if the database supports the specified feature.

Database Errors#

dbGetLastErrorNum	Returns numerical information about the last error that occurred on the database.
dbGetLastErrorText	Returns text information about the last error that occurred on the database.
dbIsOpenError	Reports whether an error occurred while attempting to open the database connection.
dbQueryGetLastErrorNum	Returns numerical error information about the last error that occurred (if any) with the last executed query.
dbQueryGetLastErrorText	Returns text error information about the last error that occurred (if any) with the last executed query.

Database Connect#

dbClose	Closes a database connection and destroys any remaining queries.
dbOpen	Opens a specified database connection using the current connection values.

Database Transaction#

dbCommit	Commits a transaction to the database if the driver supports transactions and a dbTransaction() has been started.
dbCreateQuery	Process an SQL statement and prepare a query.
dbExecQuery	Executes an SQL statement and creates a query.
dbExecQueries	Executes an SQL statement and creates a query for multiple rows of data in one function call.
dbRollback	Rolls back a transaction on the database.
dbTransaction	Begins a transaction on the database.

Query Building#

dbQueryBindValue	Set the placeholder placeholder to be bound to value val in the prepared statement.
dbQueryGetBoundValue	Returns the value for a placeholder in a query.
dbQueryGetBoundValues	Returns an Nx2 string array containing the placeholders and their corresponding values in a query.
dbQueryExecPrepared	Executes a previously created and prepared query.
dbQueryPrepare	Prepares a SQL query for execution.

Query Manipulation#

dbQueryClear	Clears the result set and releases any resources held by the query. Sets the query state to inactive.
dbQueryFinish	Instructs the database driver that no more data will be fetched from this query until it is re-executed.

Query Information#

dbQueryCols	Returns the number of fields in the record.
dbQueryGetLastInsertID	Returns the object ID of the most recent inserted row if supported by the database.
dbQueryGetLastQuery	Returns the text of the current query being used.
dbQueryGetNumRowsAffected	Reports the number of rows affected by the result’s SQL statement.
dbQueryIsActive	Returns 1 if the query is active.
dbQueryIsForwardOnly	Reports whether you can only scroll forward through a result set.
dbQueryIsNull	Reports whether the current field pointed at by an active query positioned on a valid record is NULL.
dbQueryIsSelect	Reports whether the specified query is a SELECT statement.
dbQueryIsValid	Reports whether the specified query is positioned on a valid record.
dbQueryRows	Returns the size of the result (number of rows returned), or -1 if the size cannot be determined or if the database does not support reporting information about query sizes.
dbQuerySetForwardOnly	Sets forward only mode to forward. If forward is true, only ../dbQuerySeekNext and ../dbQuerySeek with positive values, are allowed for navigating the results.

Query Iteration#

dbQueryGetPosition	Returns the current internal position of the query.
dbQuerySeek	Retrieves the record at a specified position, if available, and positions the query on the retrieved record.
dbQuerySeekFirst	Retrieves the first record in the result, if available, and positions the query on the retrieved record.
dbQuerySeekLast	Retrieves the last record in the result, if available, and positions the query on the retrieved record.
dbQuerySeekNext	Retrieves the next record in the result, if available, and positions the query on the retrieved record.
dbQuerySeekPrevious	Retrieves the previous record in the result, if available, and positions the query on the retrieved record.

Query Data Retrieval#

dbQueryFetchAllM	Returns the result set for the current query as a matrix.
dbQueryFetchAllSA	Returns the result set for the current query as a string array.
dbQueryFetchOneM	Returns a single row as an Nx1 matrix where N is the column count of the SELECT statement.
dbQueryFetchOneSA	Returns a single row as a string vector containing the field information for the current query.
dbQueryGetField	Returns the value of a specified field in the current record.

General text file manipulation#

To read and write data from CSV and delimited text files, see the earlier section.

fcheckerr	Gets the error status of a file.
fclearerr	Gets the error status of a file, then clears it.
fflush	Flushes a file’s output buffer.
fgets	Reads a line of text from a file.
fgetsa	Reads lines of text from a file into a string array.
fgetsat	Reads lines of text from a file into a string array without retaining newlines.
fgetst	Reads a line of text from a file without retaining the newline.
fopen	Opens a file.
fputs	Writes strings to a file.
fputst	Writes strings followed by a newline to a file.
fseek	Positions the file pointer in a file.
fstrerror	Returns an error message explaining the cause of the most recent file I/O error.
ftell	Gets the position of the file pointer in a file.
getf	Loads an ASCII or binary file into a string.
putf	Writes the contents of a string to a file.