2-dimensional Array - Print Black Image Depending On Number Of Rows And Columns
Nov 21, 2014
I wrote this code which print a black image depends on the number of rows and columns you give it
public class BlackImg {
private Mycolor[][] colorArr; //Mycolor is a class i wrote that represents colors.
// no need for showing the class here.
// so i created here an array of type Mycolor, for example:
// { {(255,255,255), {(127,127,0)} }
[Code] .....
my problem is that my output comes good except the last line ,
Output:
(0,0,0) (0,0,0) (0,0,0) (0,0,0)
(0,0,0) (0,0,0) (0,0,0) (0,0,0)
(0,0,0) (0,0,0) (0,0,0) (0,0,0)
BlackImg@1db9742 //what is this line , why does it showing up ?
I am continuing on in trying to build up the basics of matrix algebra from scratch.
I have created an object class called Matrix
import java.util.ArrayList; public class Matrix { public int NumRows; public int NumColumns;
// This array contains the entries of our matrix. ArrayList<Double> entry = new ArrayList<Double>();
[Code] ......
Bottom line: a matrix has a number of rows and a number of columns, and for each pair of row and column, we have a number in our matrix. The DisplayMatrix method prints my matrix to the screen, and the GetEntry method returns a particular value. This all works fine and dandy as far as I can tell.
A fundamental operation done to matrices to obtain a special matrix called the RREF is the process of switching 2 rows. Here is a method I have written that switches two rows of a matrix, and outputs the result as a new matrix. Note that I want the original matrix to be unchanged.
// Switch two rows public static Matrix SwapRows(Matrix A, int r1, int r2){ if(r1<1 || r1>A.NumRows || r2<1 || r2>A.NumRows) PRINTLN("illegally switching rows"); Matrix C = A; double dummy[] = new double[A.NumColumns];
[Code] ....
How I call this, inside a public static void main(String[] args), is as follows:
// Declares that A is a 2 by 2 matrix. Matrix A = new Matrix(2,2);
// We now add values in. The top left entry of A is 4, the top right entry of A is 1, the bottom left entry of A is 2, and the bottom right entry of A is 6.
double pony[]= new double[4]; pony[0]=4; pony[1]=1; pony[2]=2; pony[3]=6; A.AddEntries(pony);
// We can display the matrix in the output, and it looks exactly as expected!
A.DisplayMatrix();
// I am now going to create a new matrix called B. It is going to be obtained by flipping the first and second rows of A.
//Note that I want A is stay as I initialized it.
//I dont want A to have it's 2 rows switched. I want B to the matrix obtained by switching two rows of A.
Matrix B=SwapRows(A,1,2); B.DisplayMatrix();
// Displaying B gives me the desired result. However, if I now display A again, it is the same as B.
A.DisplayMatrix();
Why is my matrix A being modified? Of course, I am more than capable of providing more details/comments if requested. I suspect that this is a super silly mistake.
I am trying to write a code for multidimensional array, allocate memory for variables and access the value of the arrays. I want them to be shown as rows and columns. but my code only shows one column and no rows. here is my code:
public static void main(String[] args) { int[ ][ ] aryNumbers = new int[2][2]; aryNumbers [0][0] = 1; aryNumbers [0][1] = 2; aryNumbers [1][0] = 3; aryNumbers [1][1] = 4; int rows = 2; int columns = 2;
I have a 5x5 array of which I read from an external file and I am supposed to print out the original matrix and then add up each row and column, proceeding to store them into the sixth positions in my matrix. After that I print out the new matrix.
I am confused as to how to isolate rows and print them out. I know how to add the entire matrix up but isolation is my issue.
Here is what I have including how to read the matrix and the sum of the whole thing
import java.io.*; import java.util.*; public class prog470cAddingRandC { public static void main (String [] args) { //read the file Scanner inFile=null;
I need to write a class,that will give me output like this:
* *** **** *** *
I have to use for loop,i know that i have to use nested for loops, for rows and columns. I just cant figure it out the thing with spaces,and how to turn it to count back.
I am making rows and columns in the form of a multiplication table, listed below is my code:
package assignments; public class MultTable { public static void main (String [] args) { int row, column, x, y; for(row = 0; row < 8; row++)
[Code] .....
If you see my sample run you can see that I have the multiplication table down but, I haven't completed it. I have to make the bottom left half of the whole table blank somehow. For example, I have to make it halfway through the middle of the table the bottom left half full of white space...
5 6 7 8 9 12 14 16 18 21 24 27 32 36 90
hm, it's supposed to be the other way around horizontally.
How to sort data from a .csv file. The file has a column that contains duplicate groups, and a column that has duplicate employee id's. I need to take the data and sort it into rows. The employee's id will be in the first column, then the groups the employees belong in will occupy the following columns. The groups and employees are dynamic.
groups| empId ----------------- Group A| a1234 | Group A| e3456 | Group A| w3452 | Group A| d3456 | Group A| j7689 | [Code] ....
I want to format the .csv as follows:
-------------------------- empId | group 1 | group 2 | -------------------------- a1234 | group A | group B | --------------------------- w3452 | group A | group B | ---------------------------
I have an application that displays a GUI and this GUI displays a table with several columns and rows. I have a class that extends DefaultTableModel. I wrote the code that displays the GUI. When the database table changes, how would I updated the GUI dynamically? Do you have any sample code that does that?
i'd been using Opencsv to upload all this data into my Db(Postgres) using EclipseLink with batch inserting, it wont take more than 5 secs to load 200k+ data cause all the columns are of type string so theres no format require, the problem comes when i need to give a special format to the data that is in this table (date, Integer, etc).
Right now how it works:
- Ill go row by row (when its required) verifying the format of the data and convert it with something like this Ex: Date date = Fechas.strToDate(data, Pattern) and fill the new Object with this info
what i'm planing to do
- With the function of EclipseLink OPERATOR im gonna use that to change all the rows of a column that requires a NUMBER format with OPERATOR('ToNumber',column1,'9999999999')
i cant do the same for Date cause ill get an error if the data doesn't have a Date like pattern
how to handle this Date formatting(from a query, or directly in java).
I am simply trying to print out a deck of 54 playing cards. i have organized them in to two separate arrays the first array to place all the image icons the second array to hold the 54 Jlabels. I think my problem lies in the setLayout portion of the program . I also think my image icon path may be wrong?
import javax.swing.*; import java.awt.*; public class CardIconArray extends JFrame { private static final long serialVersionUID = 1L; final public static int numberofcards=54; CardIconArray(){
The program needs to print an isosceles triangle depending on variables Height, BorderSymbol and Interior symbol, how to do that. Here is what i did so far :
{ int height = 5; int i = 0; int count = 0; String line = "";
[code]....
and the output is a blanc page nothing on the screen only spaces...
We have triangle made of blocks. The topmost row has 1 block, the next row down has 2 blocks, the next row has 3 blocks, and so on. Compute recursively (no loops or multiplication) the total number of blocks in such a triangle with the given number of rows.
My assignment is to write some code that will multiply every number in an array by 2 and print it out. This is using a site zyante which is a interactive online book kind of thing.
I have tried For (i=0; I < 8; i++) with like userVals = userVals * 2) }
And it doesn't like that so i'm guessing i am no where close to right. The chapter doesn't give me any example of doing anything close to this so i am completely lost on what i have to do.
This is the program :
import java.util.Scanner; public class NegativeToZero { public static void main(String[] args) { Scanner scnr = new Scanner(System.in); final int NUM_ELEMENTS = 8; // Number of elements
I have a 2x2 matrix and a 2 dimensional array.Let's say, my matrix is [a b] and array is [[1, 2], [3, 4], [5, 6],[23, 11]] .I need to multiply each 1 dimensional array in above array with the matrix.For instance,
[1, 2] multiply with [a b] [3, 4] multiply with [a b] [5, 6] multiply with [a b] [23, 11] multiply with [a b]
So, each 1 dimensional array in there will be multiplied with matrix [a b] (same with matrix multiplication).how to do that multiplication in java. But I confuse how to 'release' each 1 dimensional array from the first array so I can do multiplication.How to do that in java?
I have to write a program that will read a picture and then print out the number of blocks inside it.
I have to read the picture as a binary matrix of the size r - c (number of rows times number of columns). The blocks are groups of one or more adjacent elements with the value 1.
- Blocks are built exclusively of elements with value 1 - Each element with value 1 is a part of some block - Adjacent elements with value 1 belong to the same molecule.
We only take into account the horizontal and vertical adjacency but not diagonal.
INPUT:
In the first line of the input we have the integers r and c, separated with one space. Then we have the r lines, where each contains s 0's and 1's. The numbers inside the individual lines are NOT separated by spaces.
The OUTPUT only print the number of blocks in the picture.
import java.util.Scanner; class Blocks{ public static void main(String[] args){ Scanner sc=new Scanner(System.in); char ch[][]; int rowNum=sc.nextInt(); int columnNum=sc.nextInt();
I am working through a text and I am supposed to complete the following tasks.
Your ReadFiles.java class requires the following methods:
Method: check to see if the file exists
Method: find number of rows in csv file
Method: Converts the csv file to a mutli-dimensional array
Method: PrintArray
Method: Return array using a get method
Create a file DataAnalyzer.java. This file will be used to call the methods in ReadFiles.java. Be sure to demonstrate that all of your methods work through DataAnalyzer.java.
The problem is that it does not really provide any information on how to go about reading a file into an array. I am stuck at the third task of converting the file to an array and I have tried several ways to do this unsuccessfully. I thought that I would at least try to get things to print out (line 87) to see if I could get that to work, but all that prints in null over and over again.
Java Code:
public class DataAnalyzer { public static void main (String[] args) { ReadFiles aReadFiles = new ReadFiles(); aReadFiles.fileCheck(); aReadFiles.findRows(); aReadFiles.convertFile();
I have to organize the rows from the lower to the higher number, the problem is, what I have only organizes the first 3 rows even If I insert 3,4,5...or 10 rows.
for (int i = arg[0].length - 1; i >= 0; i--) { for (int j = 0; j < i ; j++) { for (int k = 0; k < i ; k++) { if (arg[k][j] > arg[k][j + 1]) { int temp = arg[k][j];
I am very new to Java Swing. I have to create a TreeTable in Java Swing with a Parent Row having say 6 columns and its all child row having just 4 columns. like shown below
public static void displayOutputs (int[][] anArray) { System.out.println("Here is your 2Dim array:"); for (int i = 0; i < anArray.length; i++) { System.out.println(Arrays.deepToString(anArray)); } }
This is my code and I get this as a result when I input 10,20,30,...,90 into array[0][0], array[0][1], ..., array[2][2] (3rows, 3columns array)
[[10, 20, 30], [40, 50, 60], [70, 80, 90]]
[[10, 20, 30], [40, 50, 60], [70, 80, 90]]
[[10, 20, 30], [40, 50, 60], [70, 80, 90]]
While I expect to get only
[10, 20, 30]
[40, 50, 60]
[70, 80, 90]
I get no errors at least when I have the same # of rows and # of columns. However, when I have more columns than rows, a compiler stops running when it runs columnSum method.Here's an error message.
Exception in thread "main" java.lang.ArrayIndexOutOfBoundsException: 2 at lab10.Array2DMethods.columnSum(Arrays2DDemo.java:70) at lab10.Arrays2DDemo.main(Arrays2DDemo.java:111) Java Result: 1
And here's my code
public static void columnSum (int[][] anArray) { int sum =0; for (int col=0; col < anArray.length; col++) { sum=0; for (int r = 0; r < anArray[col].length; r++ ){ sum += anArray[r][col]; } System.out.println("Sum of column " + col + " = " + sum); } }
why my code doesn't work when I have more columns.
How can I find the overall averages of the columns in this array?when i run my code it gives me an output that looks like this (showing me wrong averages): 0 1 2 3 overall grade
