Documentation of 'jsat.io.CSV' Java class
CSV
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jsat.io

Class CSV


  • public class CSV
extends java.lang.Object
    Provides a reader and writer for CSV style datasets. This CSV reader supports comments in CSVs (must begin with a single character) and categorical features (columns must be specified when calling). Any number of newlines will be treated as a single newline separating two rows.

    When reading and writing a CSV, if the delimiter or comment markers are not specified - the defaults will be used DEFAULT_DELIMITER and DEFAULT_COMMENT respectively.

    The CSV loader will treat empty columns as missing values for both numeric and categorical features. A value of "NaN" in a numeric column will also be treated as a missing value. Once loaded, missing values for numeric features are encoded as Double.NaN and as -1 for categorical features.

    • Method Summary

      All Methods Static Methods Concrete Methods 
      Modifier and Type Method and Description
      static DataWriter getWriter(java.io.OutputStream out, CategoricalData[] catInfo, int dim, CategoricalData predicting, DataWriter.DataSetType type)
      Returns a DataWriter object which can be used to stream a set of arbitrary datapoints into the given output stream.
      static DataWriter getWriter(java.io.OutputStream out, CategoricalData[] catInfo, int dim, CategoricalData predicting, DataWriter.DataSetType type, char delimiter)
      Returns a DataWriter object which can be used to stream a set of arbitrary datapoints into the given output stream.
      static SimpleDataSet read(java.nio.file.Path path, char delimiter, int lines_to_skip, char comment, java.util.Set<java.lang.Integer> cat_cols)
      Reads in the given CSV dataset as a simple CSV file
      static SimpleDataSet read(java.nio.file.Path path, int lines_to_skip, java.util.Set<java.lang.Integer> cat_cols)
      Reads in the given CSV dataset as a simple CSV file
      static SimpleDataSet read(java.io.Reader reader, char delimiter, int lines_to_skip, char comment, java.util.Set<java.lang.Integer> cat_cols)
      Reads in the given CSV dataset as a simple CSV file
      static SimpleDataSet read(java.io.Reader reader, int lines_to_skip, java.util.Set<java.lang.Integer> cat_cols)
      Reads in the given CSV dataset as a simple CSV file
      static ClassificationDataSet readC(int classification_target, java.nio.file.Path path, char delimiter, int lines_to_skip, char comment, java.util.Set<java.lang.Integer> cat_cols)
      Reads in a CSV dataset as a classification dataset.
      static ClassificationDataSet readC(int classification_target, java.nio.file.Path path, int lines_to_skip, java.util.Set<java.lang.Integer> cat_cols)
      Reads in a CSV dataset as a classification dataset.
      static ClassificationDataSet readC(int classification_target, java.io.Reader reader, char delimiter, int lines_to_skip, char comment, java.util.Set<java.lang.Integer> cat_cols)
      Reads in a CSV dataset as a classification dataset.
      static ClassificationDataSet readC(int classification_target, java.io.Reader reader, int lines_to_skip, java.util.Set<java.lang.Integer> cat_cols)
      Reads in a CSV dataset as a classification dataset.
      static RegressionDataSet readR(int numeric_target_column, java.nio.file.Path path, char delimiter, int lines_to_skip, char comment, java.util.Set<java.lang.Integer> cat_cols)
      Reads in a CSV dataset as a regression dataset.
      static RegressionDataSet readR(int numeric_target_column, java.nio.file.Path path, int lines_to_skip, java.util.Set<java.lang.Integer> cat_cols)
      Reads in a CSV dataset as a regression dataset.
      static RegressionDataSet readR(int numeric_target_column, java.io.Reader reader, char delimiter, int lines_to_skip, char comment, java.util.Set<java.lang.Integer> cat_cols)
      Reads in a CSV dataset as a regression dataset.
      static RegressionDataSet readR(int numeric_target_column, java.io.Reader reader, int lines_to_skip, java.util.Set<java.lang.Integer> cat_cols)
      Reads in a CSV dataset as a regression dataset.
      static void write(DataSet<?> data, java.nio.file.Path path)
      Writes out the given dataset as a CSV file.
      static void write(DataSet<?> data, java.nio.file.Path path, char delimiter)
      Writes out the given dataset as a CSV file.
      static void write(DataSet<?> data, java.io.Writer writer)
      Writes out the given dataset as a CSV file.
      static void write(DataSet<?> data, java.io.Writer writer, char delimiter)
      Writes out the given dataset as a CSV file.

      • Methods inherited from class java.lang.Object

        equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

    • Method Detail

      • readR

        public static RegressionDataSet readR(int numeric_target_column,
                                      java.nio.file.Path path,
                                      int lines_to_skip,
                                      java.util.Set<java.lang.Integer> cat_cols)
                               throws java.io.IOException
        Reads in a CSV dataset as a regression dataset.
        Parameters:
        numeric_target_column - the column index (starting from zero) of the feature that will be the target regression value
        path - the reader for the CSV content
        lines_to_skip - the number of lines to skip when reading in the CSV (used to skip header information)
        cat_cols - a set of the indices to treat as categorical features.
        Returns:
        the regression dataset from the given CSV file
        Throws:
        java.io.IOException

      • readR

        public static RegressionDataSet readR(int numeric_target_column,
                                      java.io.Reader reader,
                                      int lines_to_skip,
                                      java.util.Set<java.lang.Integer> cat_cols)
                               throws java.io.IOException
        Reads in a CSV dataset as a regression dataset.
        Parameters:
        numeric_target_column - the column index (starting from zero) of the feature that will be the target regression value
        reader - the reader for the CSV content
        lines_to_skip - the number of lines to skip when reading in the CSV (used to skip header information)
        cat_cols - a set of the indices to treat as categorical features.
        Returns:
        the regression dataset from the given CSV file
        Throws:
        java.io.IOException

      • readR

        public static RegressionDataSet readR(int numeric_target_column,
                                      java.nio.file.Path path,
                                      char delimiter,
                                      int lines_to_skip,
                                      char comment,
                                      java.util.Set<java.lang.Integer> cat_cols)
                               throws java.io.IOException
        Reads in a CSV dataset as a regression dataset.
        Parameters:
        numeric_target_column - the column index (starting from zero) of the feature that will be the target regression value
        path - the CSV file to read
        delimiter - the delimiter to separate columns, usually a comma
        lines_to_skip - the number of lines to skip when reading in the CSV (used to skip header information)
        comment - the character used to indicate the start of a comment. Once this character is reached, anything at and after the character will be ignored.
        cat_cols - a set of the indices to treat as categorical features.
        Returns:
        the regression dataset from the given CSV file
        Throws:
        java.io.IOException

      • readR

        public static RegressionDataSet readR(int numeric_target_column,
                                      java.io.Reader reader,
                                      char delimiter,
                                      int lines_to_skip,
                                      char comment,
                                      java.util.Set<java.lang.Integer> cat_cols)
                               throws java.io.IOException
        Reads in a CSV dataset as a regression dataset.
        Parameters:
        numeric_target_column - the column index (starting from zero) of the feature that will be the target regression value
        reader - the reader for the CSV content
        delimiter - the delimiter to separate columns, usually a comma
        lines_to_skip - the number of lines to skip when reading in the CSV (used to skip header information)
        comment - the character used to indicate the start of a comment. Once this character is reached, anything at and after the character will be ignored.
        cat_cols - a set of the indices to treat as categorical features.
        Returns:
        the regression dataset from the given CSV file
        Throws:
        java.io.IOException

      • readC

        public static ClassificationDataSet readC(int classification_target,
                                          java.nio.file.Path path,
                                          int lines_to_skip,
                                          java.util.Set<java.lang.Integer> cat_cols)
                                   throws java.io.IOException
        Reads in a CSV dataset as a classification dataset. Comments assumed to start with the "#" symbol.
        Parameters:
        classification_target - the column index (starting from zero) of the feature that will be the categorical target value
        path - the CSV file to read
        lines_to_skip - the number of lines to skip when reading in the CSV (used to skip header information)
        cat_cols - a set of the indices to treat as categorical features.
        Returns:
        the classification dataset from the given CSV file
        Throws:
        java.io.IOException

      • readC

        public static ClassificationDataSet readC(int classification_target,
                                          java.io.Reader reader,
                                          int lines_to_skip,
                                          java.util.Set<java.lang.Integer> cat_cols)
                                   throws java.io.IOException
        Reads in a CSV dataset as a classification dataset. Comments assumed to start with the "#" symbol.
        Parameters:
        classification_target - the column index (starting from zero) of the feature that will be the categorical target value
        reader - the reader for the CSV content
        lines_to_skip - the number of lines to skip when reading in the CSV (used to skip header information)
        cat_cols - a set of the indices to treat as categorical features.
        Returns:
        the classification dataset from the given CSV file
        Throws:
        java.io.IOException

      • readC

        public static ClassificationDataSet readC(int classification_target,
                                          java.io.Reader reader,
                                          char delimiter,
                                          int lines_to_skip,
                                          char comment,
                                          java.util.Set<java.lang.Integer> cat_cols)
                                   throws java.io.IOException
        Reads in a CSV dataset as a classification dataset.
        Parameters:
        classification_target - the column index (starting from zero) of the feature that will be the categorical target value
        reader - the reader for the CSV content
        delimiter - the delimiter to separate columns, usually a comma
        lines_to_skip - the number of lines to skip when reading in the CSV (used to skip header information)
        comment - the character used to indicate the start of a comment. Once this character is reached, anything at and after the character will be ignored.
        cat_cols - a set of the indices to treat as categorical features.
        Returns:
        the classification dataset from the given CSV file
        Throws:
        java.io.IOException

      • readC

        public static ClassificationDataSet readC(int classification_target,
                                          java.nio.file.Path path,
                                          char delimiter,
                                          int lines_to_skip,
                                          char comment,
                                          java.util.Set<java.lang.Integer> cat_cols)
                                   throws java.io.IOException
        Reads in a CSV dataset as a classification dataset.
        Parameters:
        classification_target - the column index (starting from zero) of the feature that will be the categorical target value
        path - the CSV file
        delimiter - the delimiter to separate columns, usually a comma
        lines_to_skip - the number of lines to skip when reading in the CSV (used to skip header information)
        comment - the character used to indicate the start of a comment. Once this character is reached, anything at and after the character will be ignored.
        cat_cols - a set of the indices to treat as categorical features.
        Returns:
        the classification dataset from the given CSV file
        Throws:
        java.io.IOException

      • read

        public static SimpleDataSet read(java.nio.file.Path path,
                                 int lines_to_skip,
                                 java.util.Set<java.lang.Integer> cat_cols)
                          throws java.io.IOException
        Reads in the given CSV dataset as a simple CSV file
        Parameters:
        path - the CSV file
        lines_to_skip - the number of lines to skip when reading in the CSV (used to skip header information)
        cat_cols - a set of the indices to treat as categorical features.
        Returns:
        a simple dataset of the given CSV file
        Throws:
        java.io.IOException

      • read

        public static SimpleDataSet read(java.io.Reader reader,
                                 int lines_to_skip,
                                 java.util.Set<java.lang.Integer> cat_cols)
                          throws java.io.IOException
        Reads in the given CSV dataset as a simple CSV file
        Parameters:
        reader - the reader for the CSV content
        lines_to_skip - the number of lines to skip when reading in the CSV (used to skip header information)
        cat_cols - a set of the indices to treat as categorical features.
        Returns:
        a simple dataset of the given CSV file
        Throws:
        java.io.IOException

      • read

        public static SimpleDataSet read(java.nio.file.Path path,
                                 char delimiter,
                                 int lines_to_skip,
                                 char comment,
                                 java.util.Set<java.lang.Integer> cat_cols)
                          throws java.io.IOException
        Reads in the given CSV dataset as a simple CSV file
        Parameters:
        path - the CSV file to read
        delimiter - the delimiter to separate columns, usually a comma
        lines_to_skip - the number of lines to skip when reading in the CSV (used to skip header information)
        comment - the character used to indicate the start of a comment. Once this character is reached, anything at and after the character will be ignored.
        cat_cols - a set of the indices to treat as categorical features.
        Returns:
        a simple dataset of the given CSV file
        Throws:
        java.io.IOException

      • read

        public static SimpleDataSet read(java.io.Reader reader,
                                 char delimiter,
                                 int lines_to_skip,
                                 char comment,
                                 java.util.Set<java.lang.Integer> cat_cols)
                          throws java.io.IOException
        Reads in the given CSV dataset as a simple CSV file
        Parameters:
        reader - the reader for the CSV content
        delimiter - the delimiter to separate columns, usually a comma
        lines_to_skip - the number of lines to skip when reading in the CSV (used to skip header information)
        comment - the character used to indicate the start of a comment. Once this character is reached, anything at and after the character will be ignored.
        cat_cols - a set of the indices to treat as categorical features.
        Returns:
        a simple dataset of the given CSV file
        Throws:
        java.io.IOException

      • write

        public static void write(DataSet<?> data,
                         java.nio.file.Path path)
                  throws java.io.IOException
        Writes out the given dataset as a CSV file. If the given dataset is a regression or classification dataset, the target feature that is being predicted will always be written out as the first index in the CSV.
        After that, all numeric features will be written out in order, followed by the categorical features.
        Parameters:
        data - the dataset object to save as a CSV file
        path - the path to write the CSV to
        Throws:
        java.io.IOException

      • write

        public static void write(DataSet<?> data,
                         java.io.Writer writer)
                  throws java.io.IOException
        Writes out the given dataset as a CSV file. If the given dataset is a regression or classification dataset, the target feature that is being predicted will always be written out as the first index in the CSV.
        After that, all numeric features will be written out in order, followed by the categorical features.
        Parameters:
        data - the dataset object to save as a CSV file
        writer - the output writer to write the CSV to
        Throws:
        java.io.IOException

      • write

        public static void write(DataSet<?> data,
                         java.nio.file.Path path,
                         char delimiter)
                  throws java.io.IOException
        Writes out the given dataset as a CSV file. If the given dataset is a regression or classification dataset, the target feature that is being predicted will always be written out as the first index in the CSV.
        After that, all numeric features will be written out in order, followed by the categorical features.
        Parameters:
        data - the dataset object to save as a CSV file
        path - the path to write the CSV to
        delimiter - the delimiter between column values, normally a comma
        Throws:
        java.io.IOException

      • write

        public static void write(DataSet<?> data,
                         java.io.Writer writer,
                         char delimiter)
                  throws java.io.IOException
        Writes out the given dataset as a CSV file. If the given dataset is a regression or classification dataset, the target feature that is being predicted will always be written out as the first index in the CSV.
        After that, all numeric features will be written out in order, followed by the categorical features.
        Parameters:
        data - the dataset object to save as a CSV file
        writer - the output writer to write the CSV to
        delimiter - the delimiter between column values, normally a comma
        Throws:
        java.io.IOException

      • getWriter

        public static DataWriter getWriter(java.io.OutputStream out,
                                   CategoricalData[] catInfo,
                                   int dim,
                                   CategoricalData predicting,
                                   DataWriter.DataSetType type)
                            throws java.io.IOException
        Returns a DataWriter object which can be used to stream a set of arbitrary datapoints into the given output stream. This works in a thread safe manner. Uses the default delimiter DEFAULT_DELIMITER
        Parameters:
        out - the location to store all the data
        catInfo - information about the categorical features to be written
        dim - information on how many numeric features exist
        predicting - information on the class label, may be null if not a classification dataset
        type - what type of data set (simple, classification, regression) to be written
        Returns:
        the DataWriter that the actual points can be streamed through
        Throws:
        java.io.IOException

      • getWriter

        public static DataWriter getWriter(java.io.OutputStream out,
                                   CategoricalData[] catInfo,
                                   int dim,
                                   CategoricalData predicting,
                                   DataWriter.DataSetType type,
                                   char delimiter)
                            throws java.io.IOException
        Returns a DataWriter object which can be used to stream a set of arbitrary datapoints into the given output stream. This works in a thread safe manner.
        Parameters:
        out - the location to store all the data
        catInfo - information about the categorical features to be written
        dim - information on how many numeric features exist
        predicting - information on the class label, may be null if not a classification dataset
        type - what type of data set (simple, classification, regression) to be written
        delimiter - the character delimiter between features
        Returns:
        the DataWriter that the actual points can be streamed through
        Throws:
        java.io.IOException
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