I have 5 files text.
I merge these files into 1 file. That file contain about 60 sentences.
I want to clustering that file to 5 cluster.
I am using weka to clustering.
public static void doClustering(String pathSentences, int numberCluster) throws IOException {
Helper.deleteAllFileInFolder("results");
//so cum bang so cau trong file / so cau trung binh trong 1 file
HashMap<Integer, String> sentences = new HashMap<>();
HashMap<Integer, Integer> clustering = new HashMap<>();
try {
StringToWordVector filter = new StringToWordVector();
SimpleKMeans kmeans = new SimpleKMeans();
FastVector atts = new FastVector(5);
atts.addElement(new Attribute("text", (FastVector) null));
Instances docs = new Instances("text_files", atts, 0);
Scanner sc = new Scanner(new File(pathSentences));
int count = 0;
while (sc.hasNextLine()) {
String content = sc.nextLine();
double[] newInst = new double[1];
newInst[0] = (double) docs.attribute(0).addStringValue(content);
docs.add(new SparseInstance(1.0, newInst));
sentences.put(sentences.size(), content);
clustering.put(clustering.size(), -1);
}
NGramTokenizer tokenizer = new NGramTokenizer();
tokenizer.setNGramMinSize(10);
tokenizer.setNGramMaxSize(10);
tokenizer.setDelimiters("\\W");
filter.setTokenizer(tokenizer);
filter.setInputFormat(docs);
filter.setLowerCaseTokens(true);
filter.setWordsToKeep(1);
Instances filteredData = Filter.useFilter(docs, filter);
kmeans.setPreserveInstancesOrder(true);
kmeans.setNumClusters(numberCluster);
kmeans.buildClusterer(filteredData);
int[] assignments = kmeans.getAssignments();
int i = 0;
for (int clusterNum : assignments) {
clustering.put(i, clusterNum);
i++;
}
PrintWriter[] pw = new PrintWriter[numberCluster];
for (int j = 0; j < numberCluster; j++) {
pw[j] = new PrintWriter(new File("results/result" + j + ".txt"));
}
sentences.entrySet().stream().forEach((entry) -> {
Integer key = entry.getKey();
String value = entry.getValue();
Integer cluster = clustering.get(key);
pw[cluster].println(value);
});
for (int j = 0; j < numberCluster; j++) {
pw[j].close();
}
} catch (Exception e) {
System.out.println("Error K means " + e);
}
}
When I change the order of the input file, the clustering results also vary.
Can you help me fix it. Thanks you so much.
k-means is a randomized algorithm.
It picks some instances as initial seeds, then searches for a local optimum.
So of course it will produce different results!
If they vary a lot, this indicates it did not work well. If your data is good for k-means, then most runs will produce very similar results (except for permutation of labels).
Related
I have created a simple program that sorts integers in an input file using different algorithms. I also use filewriter to output results to another file. Unfortunately no matter how I change my code, file gets overridden. Any advice?
Been searching for answer on google and tried changing the way I input the syntax but nothing works.
important bits:
setting the writer up
try {
FileWriter fileWriter = new FileWriter ("Sorted output.txt");
//BufferedWriter bufferedWriter = new BufferedWriter (fileWriter);
PrintWriter out = new PrintWriter (new FileWriter("Sorted output.txt", true));
outputting to the file
out.println("User's own data set sorted using bubble sort.");
out.println(unsortedArray + Arrays.deepToString(FileOne));
out.println("Sorted Array looks like this:" + Arrays.toString(intArrayBubble));
out.println(timeToSort + bubbleSortIs + bubbleTime + "ms");
it works fine, however its used in a do while loop, with nested if statements, and each one overrides the other.
Rest of code in case its required - UPDATED - still not working
import java.io.*;
import java.util.*;
import java.util.concurrent.TimeUnit;
public class PDD_Sorting {
public static void main (String [] pArgs)
{
//Array for a file
String[] FileOne;
FileOne = new String[0];
int optionOne = 1,
optionTwo = 2,
optionThree = 3,
secondaryOptionOne = 1,
secondaryOptionTwo = 2,
secondaryOptionThree = 3,
userSelection,
subUserSelection;
String unsortedArray = "Unsorted array is: ",
bubbleSort = "Sorted array using bubble sort: ",
selectionSort = "Sorted array using selection sort: ",
insertionSort = "Sorted array using insertion sort: ",
timeToSort = "Time needed to sort this array using ",
bubbleSortIs = "bubble sort is ",
selectionSortIs = "selection sort is ",
insertionSortIs = "insertion sort is ",
welcomeToSorter = "Welcome to the SORTER - program that can sort your txt files containing integeres in an ascending order!",
notFiles = "Integers, not files :)",
pleaseSelect = "Please select one of the following options, by enetering a number asociated with it.",
optionOneUserInput = "1. Sort your own data set - input your own set of data (integers, separated by colons, no spaces) into the Input file.",
optionTwoPredefined = "2. Use predetermind set of data to test the algorythms.",
optionThreeExit = "3. Exit the program.",
subMenuPleaseSelect = "Please select which algorythm would you like to use to sort this file.",
optionBubble = "(1) - Bubble Sort.",
optionSelection = "(2) - Selection Sort.",
optionInsertion = "(3) - Insertion Sort.",
usersDataBubble = "User's own data set sorted using bubble sort.",
sortedArrayLooks = "Sorted Array looks like this:",
msTime = "ms",
usersDataSelection = "User's own data set sorted using selection sort.",
usersDataInsertion = "User's own data set sorted using insertion sort.",
validOption = "Please enter a valid option i.e. 1,2 or 3",
lessThanZero = "If time shown in ms is 0, that means the time needed to conduct the sort is shorter than 1ms.",
fileCreated = "File created.",
terminatingProgram = "Terminating the program.",
unableToWriteFile = "Unable to write to file";
System.out.println(welcomeToSorter);
System.out.println(notFiles);
Scanner tInput = new Scanner (System.in);
try {
FileWriter fileWriter = new FileWriter ("Sorted output.txt");
//BufferedWriter bufferedWriter = new BufferedWriter (fileWriter);
PrintWriter out = new PrintWriter (new FileWriter("Sorted output.txt", true));
do {
System.out.println(pleaseSelect);
System.out.println(optionOneUserInput);
System.out.println(optionTwoPredefined);
System.out.println(optionThreeExit);
// Scanner tInput = new Scanner (System.in);
userSelection = tInput.nextInt();
if (userSelection == optionOne) {
//System.out.println("Please enter a valid path for your file.");
String[] splitFile = null;
//String userFile = tInput.next();
FileOne = getAndPrepareFile(splitFile);
System.out.println(subMenuPleaseSelect);
System.out.println(optionBubble);
System.out.println(optionSelection);
System.out.println(optionInsertion);
subUserSelection = tInput.nextInt();
if (subUserSelection == secondaryOptionOne) {
int size = FileOne.length;
int [] intArrayBubble = new int [size];
for(int i=0; i<size; i++) {
intArrayBubble[i] = Integer.parseInt(FileOne[i]);
}
bubbleSort(intArrayBubble);
long bubbleTime = timeCount(intArrayBubble);
out.println(usersDataBubble);
out.println(unsortedArray + Arrays.deepToString(FileOne));
out.println(sortedArrayLooks + Arrays.toString(intArrayBubble));
out.println(timeToSort + bubbleSortIs + bubbleTime + msTime);
}
else if (subUserSelection == secondaryOptionTwo) {
int size2 = FileOne.length;
int [] intArraySelection = new int [size2];
for(int i=0; i<size2; i++) {
intArraySelection[i] = Integer.parseInt(FileOne[i]);
}
doSelectionSort(intArraySelection);
long selectionTime = timeCount(intArraySelection);
out.println(usersDataSelection);
out.println(unsortedArray + Arrays.deepToString(FileOne));
out.println(sortedArrayLooks + Arrays.toString(intArraySelection));
out.println(timeToSort + selectionSortIs + selectionTime + msTime);
}
else if (subUserSelection == secondaryOptionThree) {
int size3 = FileOne.length;
int [] intArrayInsertion = new int [size3];
for(int i=0; i<size3; i++) {
intArrayInsertion[i] = Integer.parseInt(FileOne[i]);
}
doInsertionSort(intArrayInsertion);
long insertionTime = timeCount(intArrayInsertion);
out.println(usersDataInsertion);
out.println(unsortedArray + Arrays.deepToString(FileOne));
out.println(sortedArrayLooks + Arrays.toString(intArrayInsertion));
out.println(timeToSort + insertionSortIs + insertionTime + msTime);
}
else {
System.out.println(validOption);
tInput.next();
}
}
else if (userSelection == optionTwo){
//file being prepared and loaded via function
String[] splitFilePredefined = null;
FileOne = getAndPrepareFilePredefined(splitFilePredefined);
//converting string array into int array so the method can sort it.
int size = FileOne.length;
int [] intArrayBubble = new int [size];
for(int i=0; i<size; i++) {
intArrayBubble[i] = Integer.parseInt(FileOne[i]);
}
int size2 = FileOne.length;
int [] intArraySelection = new int [size2];
for(int i=0; i<size2; i++) {
intArraySelection[i] = Integer.parseInt(FileOne[i]);
}
int size3 = FileOne.length;
int [] intArrayInsertion = new int [size3];
for(int i=0; i<size3; i++) {
intArrayInsertion[i] = Integer.parseInt(FileOne[i]);
}
//inserting pre-prepared int arrays into variables including a timecount method
int bubbleTime = timeCount(intArrayBubble);
int selectionTime = timeCount(intArraySelection);
int insertionTime = timeCount(intArrayInsertion);
//sorting array using various sorts
bubbleSort(intArrayBubble);
doSelectionSort(intArraySelection);
doInsertionSort(intArrayInsertion);
//out.println("Sorted arrray using insertion sort looks like this: " + Arrays.toString(intArrayInsertion));
out.println(timeToSort + bubbleSortIs + bubbleTime + "ms");
out.println(timeToSort + selectionSortIs + selectionTime + "ms");
out.println(timeToSort + insertionSortIs + insertionTime + "ms");
out.println(lessThanZero);
System.out.println(fileCreated);
}
else if (userSelection == optionThree){
System.out.println(terminatingProgram);
System.exit(0);
}
else {
System.out.println(validOption);
tInput.next();
}
out.flush();
out.close();
//tInput.close();
}while (userSelection != optionThree);
}
catch (Exception e)
{
System.out.println(unableToWriteFile);
tInput.next();
}
tInput.close();
}//end main
//method that fetches the file from predefined, hardcoded location and removes comas, esentially prepares the file for the next phase
private static String[] getAndPrepareFile (String[] splitFile)
{
Scanner fileIn = null;
try
{
fileIn = new Scanner(new FileInputStream("C:\\Users\\Greg\\Documents\\Programming\\PDD - Assignment 1\\Input.txt"));
String fileNew = fileIn.next();
splitFile = fileNew.split(",");
//System.err.println(Arrays.toString(splitFile)); //Arrays.toString needed to print the array correctly, otherwise it prints the address of the object
fileIn.close();
}
catch (IOException e)
{
System.out.println("File not found.");
//System.exit(0);
}
return splitFile;
}
//as above but works for predefined file, that can be generated using randomNumber.java program
private static String[] getAndPrepareFilePredefined (String[] splitFilePredefined)
{
Scanner fileIn = null;
try
{
fileIn = new Scanner(new FileInputStream("C:\\Users\\Greg\\Documents\\Programming\\PDD - Assignment 1\\Generated input.txt"));
String fileNew = fileIn.next();
splitFilePredefined = fileNew.split(",");
//System.err.println(Arrays.toString(splitFile)); //Arrays.toString needed to print the array correctly, otherwise it prints the address of the object
fileIn.close();
}
catch (IOException e)
{
System.out.println("File not found.");
//System.exit(0);
}
return splitFilePredefined;
}
//method used to sort a file using bubble sort
private static void bubbleSort(int[] arr) {
int n = arr.length;
int temp = 0;
for(int i=0; i < n; i++){
for(int j=1; j < (n-i); j++){
if(arr[j-1] > arr[j]){
//swap elements
temp = arr[j-1];
arr[j-1] = arr[j];
arr[j] = temp;
}
}
}
}
//method used to sort a file using selection sort
private static int[] doSelectionSort(int[] arr){
for (int i = 0; i < arr.length - 1; i++)
{
int index = i;
for (int j = i + 1; j < arr.length; j++)
if (arr[j] < arr[index])
index = j;
int smallerNumber = arr[index];
arr[index] = arr[i];
arr[i] = smallerNumber;
}
return arr;
}
//method used to sort a file using sinsertion sort
private static int[] doInsertionSort(int[] input){
int temp;
for (int i = 1; i < input.length; i++) {
for(int j = i ; j > 0 ; j--){
if(input[j] < input[j-1]){
temp = input[j];
input[j] = input[j-1];
input[j-1] = temp;
}
}
}
return input;
}
//method used to calculate how much time has lapsed while using any of the given sort methods, outputs in ms, if less than 1 ms, outputs 0ms
private static int timeCount (int[] anArray)
{
long start = System.nanoTime();
Arrays.sort(anArray);
long end = System.nanoTime();
long timeInMillis = TimeUnit.MILLISECONDS.convert(end - start, TimeUnit.NANOSECONDS);
//System.out.println("Time spend in ms: " + timeInMillis);
return (int) timeInMillis;
}
}//end class
File gets constantly overridden, how do i stop this and make it add to file instead?
You don't need the first FileWriter fileWriter = new FileWriter("Sorted output.txt");; this is actually creating/overwriting the file, after which your PrintWriter opens it again for appending.
So, just change
// ... omitting beginning
try {
FileWriter fileWriter = new FileWriter ("Sorted output.txt");
//BufferedWriter bufferedWriter = new BufferedWriter (fileWriter);
PrintWriter out = new PrintWriter (new FileWriter("Sorted output.txt", true));
do {
// ... omitting rest
to
// ... omitting beginning
try {
//BufferedWriter bufferedWriter = new BufferedWriter (fileWriter);
PrintWriter out = new PrintWriter (new FileWriter("Sorted output.txt", true));
do {
// ... omitting rest
Move out.close() outside the loop
else {
System.out.println("Please enter a valid option i.e. 1,2 or 3");
tInput.next();
}
out.flush();
/* THIS -> out.close(); <- THIS */
//tInput.close();
}while (userSelection != optionThree);
out.close();
}
I tried your code and your problem is not that the file is being overwritten, but that you are closing the outputstream in the first iteration.
I'm writing a Java LWJGL 3D game-engine. I decided to rewrite my mesh class and the .obj loader. The mesh class works fine when putting in data manually, but wehn loading from an .obj-file it gives some strange results: (it's supposed to be a dragon but lokks like a 2D ... something)
public static Mesh loadMesh(String fileName) throws IOException
{
String splitArray[] = fileName.split("\\.");
String ext = splitArray[splitArray.length-1];
if(!ext.equals("obj"))
System.err.println("Error: Engine can only load .obj files, try converting the file: " + fileName);
ArrayList<Vector3f> vertices = new ArrayList<Vector3f>();
ArrayList<Integer> vindices = new ArrayList<Integer>();
ArrayList<Integer> tindices = new ArrayList<Integer>();
ArrayList<Integer> nindices = new ArrayList<Integer>();
ArrayList<Vector3f> normals = new ArrayList<Vector3f>();
ArrayList<Vector2f> texCoords = new ArrayList<Vector2f>();
BufferedReader reader = new BufferedReader(new FileReader("./res/models/"+fileName));
String line = "";
while((line=reader.readLine())!=null)
{
String[] p = line.split(" ");
if(line.startsWith("v"))
{
vertices.add(new Vector3f(Float.valueOf(p[1]),
Float.valueOf(p[2]),
Float.valueOf(p[3])));
}
if(line.startsWith("vn"))
{
normals.add(new Vector3f(Float.valueOf(p[1]),
Float.valueOf(p[2]),
Float.valueOf(p[3])));
}
if(line.startsWith("vt"))
{
texCoords.add(new Vector2f(Float.valueOf(p[1]),
Float.valueOf(p[2])));
}
if(line.startsWith("f"))
{
String[] arg1 = p[1].split("/");
String[] arg2 = p[2].split("/");
String[] arg3 = p[3].split("/");
vindices.add(Integer.parseInt(arg1[0]));
if(arg1.length>1)
tindices.add(Integer.parseInt(arg1[1]));
if(arg1.length>2)
nindices.add(Integer.parseInt(arg1[3]));
vindices.add(Integer.parseInt(arg2[0]));
if(arg1.length>1)
tindices.add(Integer.parseInt(arg2[1]));
if(arg2.length>2)
nindices.add(Integer.parseInt(arg2[3]));
vindices.add(Integer.parseInt(arg3[0]));
if(arg1.length>1)
tindices.add(Integer.parseInt(arg3[1]));
if(arg3.length>2)
nindices.add(Integer.parseInt(arg3[3]));
}
}
float[] vdata = new float[vertices.size() * 3];
float[] tdata = new float[texCoords.size() * 2];
float[] ndata = new float[normals.size() * 3];
for(int i = 0; i < vdata.length; i++)
{
vdata[i] = vertices.get(Integer.valueOf(vindices.get(i))).getX();
vdata[i++] = vertices.get(Integer.valueOf(vindices.get(i))).getY();
vdata[i++] = vertices.get(Integer.valueOf(vindices.get(i))).getZ();
}
for(int i = 0; i < ndata.length; i++)
{
ndata[i] = normals.get(Integer.valueOf(nindices.get(i))).getX();
ndata[i++] = normals.get(Integer.valueOf(nindices.get(i))).getY();
ndata[i++] = normals.get(Integer.valueOf(nindices.get(i))).getZ();
}
for(int i = 0; i < tdata.length; i++)
{
tdata[i] = texCoords.get(Integer.valueOf(tindices.get(i))).getX();
tdata[i++] = texCoords.get(Integer.valueOf(tindices.get(i))).getY();
}
return new Mesh(vdata, tdata, ndata);
}
thats my .obj-file loader. Can't see what is wrong...
Upon closer inspection there are some nice bugs:
vindices.add(Integer.parseInt(arg1[0]));
if(arg1.length>1)
tindices.add(Integer.parseInt(arg1[1]));
if(arg1.length>2)
nindices.add(Integer.parseInt(arg1[3])); // this should be 2 for the normals
and
for(int i = 0; i < vdata.length; i++)
{
vdata[i] = vertices.get(Integer.valueOf(vindices.get(i))).getX(); //i=0
vdata[i++] = vertices.get(Integer.valueOf(vindices.get(i))).getY(); //i=0 and counted up afterwards
vdata[i++] = vertices.get(Integer.valueOf(vindices.get(i))).getZ();//i=1 and counted up afterwards
}
This is what makes the mesh two-dimensional.
I would suggest using eigther ++i or
for(int i = 0; i < vdata.length; i+=3)
{
vdata[i] = vertices.get(Integer.valueOf(vindices.get(i))).getX();
vdata[i+1] = vertices.get(Integer.valueOf(vindices.get(i))).getY();
vdata[i+2] = vertices.get(Integer.valueOf(vindices.get(i))).getZ();
}
In my Java Project, i want to read values from txt file to List method.Values seems like;
1 kjhjhhkj 788
4 klkkld3 732
89 jksdsdsd 23
Number of row changable. I have tried this codes and getting same values in all indexes.
What can i do?
String[] dizi = new String[3];
List<String[]> listOfLists = new ArrayList<String[]>();
File f = new File("input.txt");
try {
Scanner s = new Scanner(f);
while (s.hasNextLine()) {
int i = 0;
while (s.hasNext() && i < 3) {
dizi[i] = s.next();
i++;
}
listOfLists.add(dizi);
}
} catch (FileNotFoundException e) {
System.out.println("Dosyaya ba?lanmaya çal???l?rken hata olu?tu");
}
int q = listOfLists.size();
for (int z = 0; z < q; z++) {
for (int k = 0; k < 3; k++) {
System.out.print(listOfLists.get(z)[k] + " ");
}
}
String [] dizi = new String [3];
dizi is a global variable getting overridden eveytime in the loop. Thats why you are getting same values at all indexes
Make a new instance everytime before adding to the list.
You put the same reference to the list, create a new array in while loop.
while (s.hasNextLine()){
String[] dizi = new String[3]; //new array
int i = 0;
while (s.hasNext() && i < 3)
{
dizi[i] = s.next();
i++;
}
listOfLists.add(dizi);
}
So I have a text file with items like look like this:
350279 1 11:54 107.15
350280 3 11:55 81.27
350281 2 11:57 82.11
350282 0 11:58 92.43
350283 3 11:59 86.11
I'm trying to create arrays from those values, in which the first values of each line are in an array, the second values of each line are in an array, and so on.
This is all the code I have right now, and I can't seem to figure out how to do it.
package sales;
import java.io.File;
import java.io.FileNotFoundException;
import java.util.Scanner;
public class Sales {
public static void main (String[] args) throws FileNotFoundException {
Scanner reader = new Scanner(new File("sales.txt"));
int[] transID = new int[reader.nextInt()];
int[] transCode = new int[reader.nextInt()];
String[] time = new String[reader.next()];
double[] trasAmount = new double[reader.hasNextDouble()];
}
}
It's difficult to build an array this way, because Arrays have fixed size... you need to know how many elements they have. If you use a List instead, you don't have to worry about knowing the number of elements in advance. Try this (note: there is no error checking here!):
public static void main (String[] args) throws FileNotFoundException {
Scanner reader = new Scanner(new File("sales.txt"));
List<Integer> ids = new LinkedList<>();
List<Integer> codes = new LinkedList<>();
List<String> times = new LinkedList<>();
List<Double> amounts = new LinkedList<>();
// Load elements into Lists. Note: you can just use the lists if you want
while(reader.hasNext()) {
ids.add(reader.nextInt());
codes.add(reader.nextInt());
times.add(reader.next());
amounts.add(reader.nextDouble());
}
// Create arrays
int[] idArray = new int[ids.size()];
int[] codesArray = new int[codes.size()];
String[] timesArray = new String[times.size()];
double[] amountsArray = new double[amounts.size()];
// Load elements into arrays
int index = 0;
for(Integer i : ids) {
idArray[index++] = i;
}
index = 0;
for(Integer i : codes) {
codesArray[index++] = i;
}
index = 0;
for(String i : times) {
timesArray[index++] = i;
}
index = 0;
for(Double i : ids) {
amountsArray[index++] = i;
}
}
Use Array list because Arrays have fixed size and using Arraylist you add the elements dynamically
Scanner reader = new Scanner(new File("test.txt"));
List<Integer> transID = new ArrayList<Integer>();
List<Integer> transCode = new ArrayList<Integer>();
List<String> time= new ArrayList<String>();
List<Double> trasAmount = new ArrayList<Double>();
while(reader.hasNext() )
{
transID.add(reader.nextInt());
transCode.add(reader.nextInt());
time.add(reader.next());
trasAmount.add(reader.nextDouble());
}
System.out.println(transID.toString());
System.out.println(transCode.toString());
System.out.println(time.toString());
System.out.println(trasAmount.toString());
Output of the above code
transID [350279, 350280, 350281, 350282, 350283]
transCode [1, 3, 2, 0, 3]
time [11:54, 11:55, 11:57, 11:58, 11:59]
trasAmount [107.15, 81.27, 82.11, 92.43, 86.11]
You'll need a while loop to check for input. Since not all inputs are integers you might do something like:
while(reader.hasNextLine()){ //checks to make sure there's still a line to be read in the file
String line=reader.nextLine(); //record that next line
String[] values=line.split(" "); //split on spaces
if(values.length==4){
int val1=Integer.parseInt(values[0]); //parse values
int val2=Integer.parseInt(values[1]);
String val3=values[2];
double val4=Double.parseDouble(values[3]);
//add these values to your arrays. Might have to "count" the number of lines on a first pass and then run through a second time... I've been using the collections framework for too long to remember exactly how to work with arrays in java when you don't know the size right off the bat.
}
}
In addition to my comment here are 3 ways how you cant do it
read into single arrays
int size = 2;
// first allocate some memory for each of your arrays
int[] transID = new int[size];
int[] transCode = new int[size];
String[] time = new String[size];
double[] trasAmount = new double[size];
Scanner reader = new Scanner(new File("sales.txt"));
// keep track of how many elements you have read
int i = 0;
// start reading and continue untill there is no more left to read
while(reader.hasNext()) {
// since array size is fixed and you don't know how many line your file will have
// you have to reallocate your arrays when they have reached their maximum capacity
if(i == size) {
// increase capacity by 5
size += 5;
// reallocate temp arrays
int[] tmp1 = new int[size];
int[] tmp2 = new int[size];
String[] tmp3 = new String[size];
double[] tmp4 = new double[size];
// copy content to new allocated memory
System.arraycopy(transID, 0, tmp1, 0, transID.length);
System.arraycopy(transCode, 0, tmp2, 0, transCode.length);
System.arraycopy(time, 0, tmp3, 0, time.length);
System.arraycopy(trasAmount, 0, tmp4, 0, trasAmount.length);
// reference to the new memory by your old old arrays
transID = tmp1;
transCode = tmp2;
time = tmp3;
trasAmount = tmp4;
}
// read
transID[i] = Integer.parseInt(reader.next());
transCode[i] = Integer.parseInt(reader.next());
time[i] = reader.next();
trasAmount[i] = Double.parseDouble(reader.next());
// increment for next line
i++;
}
reader.close();
for(int j = 0; j < i; j++) {
System.out.println("" + j + ": " + transIDList.get(j) + ", " + transCodeList.get(j) + ", " + timeList.get(j) + ", " + trasAmountList.get(j));
}
as you see this is a lot of code.
Better you use lists so get rid of the overhead of reallocation and copying (at leas in your own code)
read into single lists
// instanciate your lists
List<Integer> transIDList = new ArrayList<>();
List<Integer> transCodeList = new ArrayList<>();
List<String> timeList = new ArrayList<>();
List<Double> trasAmountList = new ArrayList<>();
reader = new Scanner(new File("sales.txt"));
int i = 0;
while(reader.hasNext()) {
// read
transIDList.add(Integer.parseInt(reader.next()));
transCodeList.add(Integer.parseInt(reader.next()));
timeList.add(reader.next());
trasAmountList.add(Double.parseDouble(reader.next()));
i++;
}
reader.close();
for(int j = 0; j < i; j++) {
System.out.println("" + j + ": " + transIDList.get(j) + ", " + transCodeList.get(j) + ", " + timeList.get(j) + ", " + trasAmountList.get(j));
}
You see here how small the code went? But but it still can get better...
A line in the sales.txt file seem to constitute data elements of some entity, why not put them in an object ? for that you may write a class named Trans, some think like this:
class Trans {
public int transID;
public int transCode;
public String time;
public double trasAmount;
#Override
public String toString() {
return transID + ", " + transCode + ", " + time + ", " + trasAmount;
}
}
Then you can use this class to hold the data you read from your file and put each object of that class in a list.
reading into a list of objects
reader = new Scanner(new File("sales.txt"));
List<Trans> transList = new ArrayList<>();
int i = 0;
while(reader.hasNext()) {
Trans trans = new Trans();
trans.transID = Integer.parseInt(reader.next());
trans.transCode = Integer.parseInt(reader.next());
trans.time = reader.next();
trans.trasAmount = Double.parseDouble(reader.next());
transList.add(trans);
i++;
}
reader.close();
for(Trans trans : transList) {
System.out.println("" + i++ + ": " + trans);
}
Output of all 3 methods
0: 350279, 1, 11:54, 107.15
1: 350280, 3, 11:55, 81.27
2: 350281, 2, 11:57, 82.11
3: 350282, 0, 11:58, 92.43
4: 350283, 3, 11:59, 86.11
Here is a sample code to read the values from the file and write into an array. Sample code has logic for int array, you can replicate it for other array types as well.
package sales;
import java.io.BufferedReader;
import java.io.DataInputStream;
import java.io.FileInputStream;
import java.io.IOException;
import java.io.InputStreamReader;
public class Sales {
public static void main (String[] args) throws IOException {
FileInputStream fstream = new FileInputStream("sales.txt");
BufferedReader br = new BufferedReader(new InputStreamReader(fstream));
String strLine;
while ((strLine = br.readLine()) != null) {
String[] tokens = strLine.split(" ");
int[] transID = convertStringToIntArray(tokens[0]);
for(int i = 0 ; i < transID.length ; i++ )
System.out.print(transID[i]);
}
}
/** function to convert a string to integer array
* #param str
* #return
*/
private static int[] convertStringToIntArray(String str) {
int intArray[] = new int[str.length()];
for (int i = 0; i < str.length(); i++) {
intArray[i] = Character.digit(str.charAt(i), 10);
}
return intArray;
}
}
I have a directory in which I have 1000 txt.files in it. I want to know for every word how many times it occurs in the 1000 document. So say even the word "cow" occured 100 times in X it will still be counted as one. If it occured in a different document it is incremented by one. So the maximum is 1000 if "cow" appears in every single document. How do I do this the easy way without the use of any other external library. Here's what I have so far
private Hashtable<String, Integer> getAllWordCount()
private Hashtable<String, Integer> getAllWordCount()
{
Hashtable<String, Integer> result = new Hashtable<String, Integer>();
HashSet<String> words = new HashSet<String>();
try {
for (int j = 0; j < fileDirectory.length; j++){
File theDirectory = new File(fileDirectory[j]);
File[] children = theDirectory.listFiles();
for (int i = 0; i < children.length; i++){
Scanner scanner = new Scanner(new FileReader(children[i]));
while (scanner.hasNext()){
String text = scanner.next().replaceAll("[^A-Za-z0-9]", "");
if (words.contains(text) == false){
if (result.get(text) == null)
result.put(text, 1);
else
result.put(text, result.get(text) + 1);
words.add(text);
}
}
}
words.clear();
}
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
System.out.println(result.size());
return result;
}
You also need a HashSet<String> in which you store each unique word you've read from the current file.
Then after every word read, you should check if it's in the set, if it isn't, increment the corresponding value in the result map (or add a new entry if it was empty, like you already do) and add the word to the set.
Don't forget to reset the set when you start to read a new file though.
how about this?
private Hashtable<String, Integer> getAllWordCount()
{
Hashtable<String, Integer> result = new Hashtable<String, Integer>();
HashSet<String> words = new HashSet<String>();
try {
for (int j = 0; j < fileDirectory.length; j++){
File theDirectory = new File(fileDirectory[j]);
File[] children = theDirectory.listFiles();
for (int i = 0; i < children.length; i++){
Scanner scanner = new Scanner(new FileReader(children[i]));
while (scanner.hasNext()){
String text = scanner.next().replaceAll("[^A-Za-z0-9]", "");
words.add(text);
}
for (String word : words) {
Integer count = result.get(word)
if (result.get(word) == null) {
result.put(word, 1);
} else {
result.put(word, result.get(word) + 1);
}
}
words.clear();
}
}
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
System.out.println(result.size());
return result;
}