Method pointToBytes

JSAT/src/jsat/io/CSV.java:789–839

(DataPoint dp, double label, ByteArrayOutputStream byteOut)

            }
            
            @Override
            protected void pointToBytes(DataPoint dp, double label, ByteArrayOutputStream byteOut)
            {
                PrintWriter writer = new PrintWriter(byteOut);
                boolean nothingWrittenYet = true;
            
                //target feature always goes at the front
                if(type == DataWriter.DataSetType.CLASSIFICATION)
                {
                    int targetClass = (int) label;
                    writer.write(classNames[targetClass]);
                    nothingWrittenYet = false;
                }
                else if(type == DataWriter.DataSetType.REGRESSION)
                {
                    double targetVal = label;
                    writer.write(Double.toString(targetVal));
                    nothingWrittenYet = false;
                }

                Vec v =dp.getNumericalValues();
                int[] c = dp.getCategoricalValues();


                //write out numeric features first
                for(int j = 0; j < v.length(); j++)
                {
                    if(!nothingWrittenYet)
                        writer.write(delimiter);

                    //bellow handles NaN correctly, rint will just return NaN and then toString prints "NaN"
                    double val = v.get(j);
                    if(Math.rint(val) == val)//cast to long before writting to save space
                        writer.write(Long.toString((long) val));
                    else
                        writer.write(Double.toString(val));
                    nothingWrittenYet = false;
                }
                //then categorical features, useing the safe names we constructed earlier
                for(int j = 0; j < c.length; j++)
                {
                    if(!nothingWrittenYet)
                        writer.write(delimiter);
                    if(c[j] >= 0)
                        writer.write(catNamesToUse[j][c[j]]);
                    //else, its negative - which is missing, so not writing anything out should result in the correct behavior
                    nothingWrittenYet = false;
                }
                writer.write("\n");
                writer.flush();
            }
        };
        return dw;
    }