I have to write sorting algorithm for numbers given on standard input(console) with following requirements:
The application must remember the distinction between double and integer numbers. This must be evident in the sorted output. Double type numbers are written using a period (.) to separate the fraction from the whole part.
The problem is I don't know how to efficiently distinct whether something is an int or double on standard input, to save them into 2 different arrays.
Only idea I've come to so far is to read each number as String and check if it has '.' character, to figure out if it's double and than convert it into right type and add it to correct array.
Also thought that maybe this would be achieveable using Pattern but how to do that?
I am using jdk 6 ... I came to know that how we can read strings from user input ... and how we can convert a string to int .. but i dont fount how to read a character by character from user ..
The following program should read in a file on my desktop (I have the path set in Netbeans to that location) and produce a Histogram. Instead I am receiving this error.
Exception in thread "main" javax.imageio.IIOException: Can't read input file! at javax.imageio.ImageIO.read(ImageIO.java:1301) at Histogram.main(Histogram.java:9) Java Result: 1 BUILD SUCCESSFUL (total time: 0 seconds)
Here is the code for the Histogram:
import java.awt.image.BufferedImage; import java.io.File; import javax.imageio.ImageIO; public class Histogram { public static void main(String[] args) throws Exception { int[][][] ch = new int[4][4][4];
I am having trouble taking user input and passing it to another class as a variable. If I assign the value explicitly (see line 59), it works just fine. What I want to do though, is assign the input from inputField to the variable inputVariable. I tried using:
inputVariable = inputField.getText();
This does not work. Regardless of what is typed into inputField, the output I get is just:
public void savePlants(ArrayList flowerPack) throws IOException { Scanner input = new Scanner(System.in); String name;
[Code].....
When I open the saved file the information I need seems to be saved, but when I try to load and search it the data is not there. This is homework that was due about 2 days ago. I just want to get it right in my head for next time.
I am required to read user input to create two matrices which will eventually be added together. I am unsure as to how I can read the input from the user as an int and not a String. The input is from size 0-10 for both column and row size. Also, can you have a new button created in the actionPerformed method of a previous button?
import javax.swing.*; import java.awt.*; import java.awt.event.*; import java.util.*; public class Matrices implements ActionListener { private JFrame win1, win2, win3, win4;
The project is a program that allows the user to enter students and enter grades for each student. One of the requirements is that if there is already a grade stored for the student that it will display the previous grade. IF the user then enters a new grade the new grade will be stored. IF the user simply presses enter (enters an empty string) nothing is done. I have everything working except for the requirement of doing nothing if the user enters an empty string. If I just press enter at this point I get a NumberFormatException.
The below code is a method "setTestGrades" from the student class. This method iterates through each student object stored in an array list and then checks if there is a previous grade (Requirement# unset grades have to default to -1) before allowing the user to set a new grade.
public void setTestGrades(int testNumber) { //Sets the grade for the specified test number for each student in the arraylist. testNumber -= 1; Scanner input = new Scanner(System.in); for (int i = 0; i < studentList.size(); i++) { System.out.println("Please enter the grade for Test #" + (testNumber + 1) + " For Student " + studentList.get(i).getStudentName());
The basic gist is it's "A program that reads in a text file that uses a specific input format and uses it to produce a formatted report for output."
Specifically :"For this lab you will write a Java program that produces a simple formatted report. The program will prompt the user to enter a file name. This file must contain information in a specific format (detailed below). Each "block" of the file contains information for one player in a competition -- the name of the player followed by a number of different scores that that player achieved. The program should find each player's average score, median score and best and worst scores and display them in a line on the final summary report. The program should also determine which player has the highest average score and which player has the lowest average score."
I get the following errors when I try and compile it:
Enter an input file name: Project11.txt Exception in thread "main" java.lang.ArrayIndexOutOfBoundsException... -1 at java.util.ArrayList.elementData(Unknown Source) at java.util.ArrayList.get(Unknown Source) at Project11.getMedian(Project11.java:68) at Project11.main(Project11.java:27)
I get that the error(s) reside in lines 68 and 27, among problem other areas, but I'm not exactly sure how I can fix them.
Here's my code:
import java.io.*; import java.util.*; public class Project11 { public static void main(String[] args) throws IOException{ Scanner in = new Scanner(System.in); System.out.print("Enter an input file name: "); String input = in.nextLine();
for standard deviation my output is not rounded to the 10's place, how can I make it round to the 10's place. Here is my code.
import java.util.*; public class chapter7 { public static final int Max_Number_Scores = 100; public static int fillArray(double[] scores) { System.out.print("You entered "); for (int i = 0; i < scores.length; i++) { System.out.print(scores[i] + " ");
I was wondering how Java knows where to Import classes from when we don't specify the whole directory path.
For example: import java.util.* Does It automatically search In both your current directory and the directory created during Installation that contains the standard library (wherever It may have been Installed) ?
It may be (it is highly likely) possible that I have royally stuffed this up. I am attempting to write a program that asks a user for a file name, gets the number of entries and if there is more than one entry calculate the mean, variance and standard deviation. This is my code so far:
/* Calculate contains methods that determines the number of data entries in a file, and calculates the mean, variance and standard deviation of this set * ************************************************************************/ import java.util.Scanner; import java.io.*; public class Calculate { public static void main(String[] args) throws IOException { // Create a Scanner object for keyboard input. Scanner keyboard = new Scanner(System.in);
[Code] ....
The errors I am getting are:
Calculate.java:67: error: ';' expected mean += mean/String filename; ^ Calculate.java:67: error: not a statement mean += mean/String filename;
I am facing NoClassDefFoundError with one of the java standard platform class (java.text.DigitList$1)
java.text.DigitList class is part of rt.jar so it should not create any issue as such.
I am using Java 1.6.0_06
StackTrace: Unhandled exception java.lang.NoClassDefFoundError: java/text/DigitList$1 at java.text.DigitList.shouldRoundUp(DigitList.java:4 11) at java.text.DigitList.round(DigitList.java:363) at java.text.DigitList.set(DigitList.java:351) at java.text.DigitList.set(DigitList.java:272) at java.text.DecimalFormat.format(DecimalFormat.java: 584) at java.text.DecimalFormat.format(DecimalFormat.java: 507) at java.text.NumberFormat.format(NumberFormat.java:26 9)
Code: package button; import javax.swing.*; import java.awt.event.*; public class Actions extends JFrame implements ActionListener { JPanel pnl = new JPanel();
[Code] ....
Errors: Exception in thread "main" java.lang.Error: Unresolved compilation problems: The type Actions must implement the inherited abstract method ActionListener.actionPerformed(ActionEvent) event cannot be resolved event cannot be resolved at button.Actions.<init>(Actions.java:4) at button.Actions.main(Actions.java:9)
I'm using netbeans to develop an application to send and receive data via RS 232 standard. I can send data but I can't read it.what can I do? I have this message in the console: Underlying input stream returned zero bytes. (I must use also threads to have application in real time but I don't understand very well....
Basically I'm trying to compute the standard deviation for a set of numbers and I'm using previously know data to compute this. The data I'm working with is here (note all of this is fake as its for an assignment):
Next this is the code that I know is producing the error:
/** * Pass in original data from files, and pass in computed grades as arraylist. this returns all of the standard deviations to be printed */ public static ArrayList calcStandDev(String data1[], ArrayList<Double> grades, ArrayList<Integer> averages) { double standDev = 0; int j = 0; //gets rid of first element in string array, makes processing MUCH easier String[] data = Arrays.copyOfRange(data1, 1, data1.length);
[Code] ....
Look for the line with all the ***'s, it is producing the "java.lang.ClassCastException: java.lang.Double cannot be cast to java.lang.Integer".
The reason I dont undersand why its producing this error is because temp.get(i) should be a integer - averages.get(i) (is type double), I do believe automatic up casting is present here making them both a double then I multiply it by itself producing a double? I dont understand where the casing is occurring. And just incase you want the formula I'm using for standard deviation here it is:
I am trying to create a method that calculates the standard deviation of array. What I want to be able to do is something like this
package standardDevaitionAndMean; public class StandardDeviationTest { public static void main (String[] args) { int [] array = {12,12,12,12,12,12,12}; standardDev = array.StandardDevation(); System.out.print(standardDev); } }
With something like this
package standardDevaitionAndMean; public class StandardDeviation {double mean1; double standDev; public double Mean(double ... array) { for(int i=0; i<array.length;i++)
[Code]...
So basically I want to be able to make an array in a class and be able to calculate its standard deviation with my method in my other class. I know the code I wrote is terrible but I just wanted to show what I am trying to do. I am kind of shaky on how arrays operate
The purpose of this program is to import via keyboard Numbers.txt and calculate the mean and standard deviation to Results.txt.I am able to get the mean calculate but when I open the Results.txt the standard deviation is 0. I don't know what is wrong with my code, but I believe it has something to do with the scanner being close. Here is the error message i receive after inputting Numbers.txt.
java.lang.IllegalStateException: Scanner closed at java.util.Scanner.ensureOpen(Unknown Source) at java.util.Scanner.hasNext(Unknown Source) at StatsDemo.main(StatsDemo.java:48) at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source) at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source) at java.lang.reflect.Method.invoke(Unknown Source) at edu.rice.cs.drjava.model.compiler.JavacCompiler.runCommand(JavacCompiler.java:272)
Java Code:
import java.text.DecimalFormat; //for number formatting import java.util.Scanner; //for keyboard input import java.io.*; //for using files public class StatsDemo { public static void main(String [] args) throws IOException
I have two classes. time_runner is used for testing my code.
This is what I'm using to test my code:
class time_runner { public static void main(String str[]) throws IOException { Time time1 = new Time(14, 56); System.out.println("time1: " + time1); System.out.println("convert time1 to standard time: " + time1.convert()); System.out.println("time1: " + time1); System.out.print("increment time1 five times: "); time1.increment();
[code]....
The two constructors are "Time()", which is the default constructor that sets the time to 1200, and "Time(int h, int m)" Which says If h is between 1 and 23 inclusive, set the hour to h. Otherwise, set the hour to 0. If m is between 0 and 59 inclusive, set the minutes to m. Otherwise, set the minutes to 0. Those are my two constructors that I pretty much have down. The three methods however I'm having trouble with. The "String toString()" Returns the time as a String of length 4. The "String convert()" Returns the time as a String converted from military time to standard time. The "void increment()" Advances the time by one minute.
public class Time { private int hour; private int minute; public Time(int h, int m) { if(h > 1 && h < 23) hour = h;
I am trying to write a program that will generate a QR Code from an input text and also display some information about the input/output bits. So far I have created the frame and what to do next. And I'm not sure if I am on the right track since my level of programming is not that great. By the way, I am using zxing libraries from GitHub. I know, there are plenty of generators online for the QR Code, but that is not what I am looking for. As you can see on the attached image, I am more interested in the efficiency of encoding 2D data. Also, I noticed that almost all the online projects regarding 2D codes are for Android. Which is not very useful.
So I was going to try to create a program that prompts input and creates a file (That didn't exist before) with that input as name.Then, the program prompts inputs after stating questions such as 1 + 1, then if the user inputs an answer, put "Question # = Correct "or" Wrong.Code SO Far:
Java Code:
import java.io.BufferedReader; import java.io.File; import java.io.InputStreamReader; public class File_Read { public File_Read() {//File_Read is the Interactive object
[code]....
So that it puts the Correct or Wrong into the file.
class Client{ public static void main(String []args){ Bike R1=new Bike(5.0, 60.0,30.0);//create bike object with params Bike R2=new Bike();//without params System.out.println(R1.increaseSpeed());//calling methods System.out.println(R1.maxDistance()); System.out.println(R2.increaseSpeed()); System.out.println(R2.maxDistance()); } }
