im trying to create a 3x3 matrix in c# language, i know how to create the matrix but i need help for user input numbers. I hope someone can help me thank you for that.
I will add a while loop and use double.TryParse to validate user's input. Usin BWHazel's code:
const int MATRIX_ROWS = 3;
const int MATRIX_COLUMNS = 3;
double[,] matrix = new double[MATRIX_ROWS, MATRIX_COLUMNS];
for (int i = 0; i < MATRIX_ROWS; i++)
{
for (int j = 0; j < MATRIX_COLUMNS; j++)
{
double input;
Console.Write("Enter value for ({0},{1}): ", i, j);
while (!double.TryParse(Console.ReadLine(), out input)
{
Console.Write("Enter correct value for ({0},{1}): ", i, j);
}
matrix[i,j] = input
}
}
To get the totals for all rows you can use following snippet:
for (int i = 0; i < MATRIX_ROWS; i++)
{
// The some for each row
double sum = 0.0;
for (int j = 0; j < MATRIX_COLUMNS; j++)
{
sum += matrix[i,j];
}
Console.WriteLine(string.format("The sum for row {0} is: {1}", i, sum));
}
If you are using the command-line, something like this should work:
const int MATRIX_ROWS = 3;
const int MATRIX_COLUMNS = 3;
double[,] matrix = new double[MATRIX_ROWS, MATRIX_COLUMNS];
for (int i = 0; i < MATRIX_ROWS; i++)
{
for (int j = 0; j < MATRIX_COLUMNS; j++)
{
Console.Write("Enter value for ({0},{1}): ", i, j);
matrix[i,j] = double.Parse(Console.ReadLine());
}
}
This assumes you are using double for the values. The .Parse() method is available for all .NET numeric types including int.
private void button1_Click(object sender, EventArgs e)
{
txtResult.Text=GenerateMatrix(Int32.Parse(txtRow.Text), Int32.Parse(txtColumn.Text));
}
private string GenerateMatrix(int Row,int Column)
{
string matrix = string.Empty;
string Result = string.Empty;
int nxtline=0;
for (int i = 0; i < Row; i++)
{
for (int j = 0; j < Column; j++)
{
if (nxtline==Column)
{
matrix = matrix + Environment.NewLine;
nxtline = 0;
}
matrix = matrix+"*";
nxtline = nxtline + 1;
}
}
Result = matrix;
return Result;
}
Related
Hi i am trying to calculate the sums of the submatrix of order K from a matrix of order M, but I am getting wrong result from the sums matrix. In my head the logic makes sense, I don't know what the mistake is.
static void Main(string[] args)
{
Console.WriteLine("Shkruani te madhesine e matrices dhe madhesine e submatrices: ");
int M;
int K;
int sum = 0;
M = int.Parse(Console.ReadLine());
K = int.Parse(Console.ReadLine());
int[] sums = new int[M - K + 1];
int[] matrix = new int[M];
Console.WriteLine("Shkruani vlerat e matrices: ");
foreach (int i in matrix)
{
matrix[i] = int.Parse(Console.ReadLine());
}
for (int i = 0; i <= M - K; i++)
{
for (int j = 0; j < K; j++)
{
sum += matrix[i + j];
}
sums[i] = sum;
sum = 0;
}
for (int i = 0; i < (M - K + 1); i++)
{
Console.WriteLine(sums[i]);
}
Console.ReadKey();
}
Instead of using
foreach (int i in matrix)
{
matrix[i] = int.Parse(Console.ReadLine());
}
Use this:
for (int i = 0; i < matrix.Length; i++)
{
matrix[i] = int.Parse(Console.ReadLine());
}
Explanation:
Because For-Each loop works with value (iterate through value) instead of index (May be what you want) while for loop works with index (iterate through index).
Hope this helps.
Thank you.
Here's my code
public int[,] GetBigEyeRoad(int x)
{
int[,] arrayBigEyeResult = new int[6, x];
Array.Copy(arrayBigEyeRoad, arrayBigEyeResult, arrayBigEyeRoad.GetLength(0) * arrayBigEyeRoad.GetLength(1));
return arrayBigEyeResult;
}
And calling it on my main class like this
int[,] arrayBigEyeRoad = bsb.GetBigEyeRoad(104);
string s = "";
for (int y = 0; y < arrayBigEyeRoad.GetLength(0); y++)
{
for (int x = 0; x < arrayBigEyeRoad.GetLength(1); x++)
{
s += string.Format("{0:D2}", arrayBigEyeRoad[y, x]);
s += ".";
}
s += "\n";
}
Debug.Log(s);
Here on this part
int[,] arrayBigEyeRoad = bsb.GetBigEyeRoad(104);
I only want to display 12 2D array values just like this
int[,] arrayBigEyeRoad = bsb.GetBigEyeRoad(12);
The problem is that it won't let me . Because it will give me an error saying
Destination array was not long enough. Check destIndex and length, and the array's lower bounds
Now how can I possible do it something like this
Limit the 2d display on the console
Pretty simple:
int[,] a1 = new int[100,200];
int[,] a2 = new int[10,5];
for (int i = 0; i < 10; i++)
for (int j = 0; j < 5; j++)
a2[i,j] = a1[i,j];
or
public class MyArray : int[,]
{
public override string ToString()
{
string result = "";
for (int i = 0; i < 10; i++)
for (int j = 0; j < 5; j++)
result += (a1[i,j].ToString() + ",");
return result;
}
}
Below is the code I wrote for clustering using genetic algorithm. Points are from a picturebox, generated randomly (X,Y) before calling this class. However, the result of this algorithm is much worse than k-means or lbg I'm comparing it to. Can someone take a look for any errors in the algorithm, maybe I omitted something. Thanks.
I did this using arrays, the 2 other I did using lists, but I don't think that should have any impact on result.
public class geneticAlgorithm
{
static int pom = 0;
static PictureBox pb1;
public geneticAlgorithm(PictureBox pb)
{
pb1 = pb;
}
public static void doGA(PointCollection points, int clusterCounter)
//points is a list of points,
//those point have (X,Y) coordinates generated randomly from pictureBox
//coordinates. clusterCounter is how many clusters I want to divide the points into
{
//this part converts list of points into array testtab,
//where each array field hold X,Y of a point
Point[] test = new Point[points.Count];
test = points.ToArray();
double[][] testtab = new double[test.Length][];
for (int i = 0; i < testtab.GetLength(0); i++)
{
testtab[i] = new double[2];
testtab[i][0] = test[i].X;
testtab[i][1] = test[i].Y;
}
//end of converting
int n = testtab.GetLength(0);
int k = clusterCounter;
int chromosomeCount = 500;
int dimensions = 2;
double[][] testClusters = new double[k][];
for (int i = 0; i < k; i++)
{
testClusters[i] = new double[dimensions];
}
double[][] testChromosomes = new double[chromosomeCount][];
for (int i = 0; i < chromosomeCount; i++)
{
testChromosomes[i] = new double[2 * k];
}
int[][] testChromosomesInt = new int[chromosomeCount][];
for (int i = 0; i < chromosomeCount; i++)
{
testChromosomesInt[i] = new int[2 * k];
}
double[] partner = new double[chromosomeCount];
double[][] roulette = new double[chromosomeCount][];
for (int i = 0; i < chromosomeCount; i++)
{
roulette[i] = new double[1];
}
double[][] errors = new double[chromosomeCount][];
for (int i = 0; i < chromosomeCount; i++)
{
errors[i] = new double[1];
}
double crossingPossibility = 0.01;
double mutationPossibility = 0.0001;
int maxIterations = 10000;
//here I create chromosomes and initial clusters
for (int j = 0; j < chromosomeCount; j++)
{
for (int i = 0; i < k; i++)
{
Random rnd = new Random();
int r = rnd.Next(n);
for (int q = 0; q < dimensions; q++)
{
testClusters[i][q] = testtab[r][q];
}
}
int help = 0;
for (int i = 0; i < k; i++)
for (int l = 0; l < dimensions; l++) // here is creation of chromosome
{
testChromosomes[j][help] = testClusters[i][l];
help++;
}
//end
//here I call accomodation function to see which of them are good
errors[j][0] = accomodationFunction(testClusters, testtab, n, k);
//end
//cleaning of the cluster table
testClusters = new double[k][];
for (int i = 0; i < k; i++)
{
testClusters[i] = new double[dimensions];
}
}
//end
for (int counter = 0; counter < maxIterations; counter++)
{
//start of the roulette
double s = 0.0;
for (int i = 0; i < chromosomeCount; i++)
s += errors[i][0];
for (int i = 0; i < chromosomeCount; i++)
errors[i][0] = chromosomeCount * errors[i][0] / s;
int idx = 0;
for (int i = 0; i < chromosomeCount; i++)
for (int j = 0; i < errors[i][0] && idx < chromosomeCount; j++)
{
roulette[idx++][0] = i;
}
double[][] newTab = new double[chromosomeCount][];
for (int i = 0; i < chromosomeCount; i++)
{
newTab[i] = new double[2 * k];
}
Random rnd = new Random();
for (int i = 0; i < chromosomeCount; i++)
{
int q = rnd.Next(chromosomeCount);
newTab[i] = testChromosomes[(int)roulette[q][0]];
}
testChromosomes = newTab;
//end of roulette
//start of crossing chromosomes
for (int i = 0; i < chromosomeCount; i++)
partner[i] = (rnd.NextDouble() < crossingPossibility + 1) ? rnd.Next(chromosomeCount) : -1;
for (int i = 0; i < chromosomeCount; i++)
if (partner[i] != -1)
testChromosomes[i] = crossing(testChromosomes[i], testChromosomes[(int)partner[i]], rnd.Next(2 * k), k);
//end of crossing
//converting double to int
for (int i = 0; i < chromosomeCount; i++)
for (int j = 0; j < 2 * k; j++)
testChromosomes[i][j] = (int)Math.Round(testChromosomes[i][j]);
//end of conversion
//start of mutation
for (int i = 0; i < chromosomeCount; i++)
if (rnd.NextDouble() < mutationPossibility + 1)
testChromosomesInt[i] = mutation(testChromosomesInt[i], rnd.Next(k * 2), rnd.Next(10));
//end of mutation
}
//painting of the found centre on the picture box
int centrum = max(errors, chromosomeCount);
Graphics g = pb1.CreateGraphics();
SolidBrush brush = new SolidBrush(Color.Red);
for (int i = 0; i < 2 * k - 1; i += 2)
{
g.FillRectangle(brush, testChromosomesInt[centrum][i], testChromosomesInt[centrum][i + 1], 20, 20);
}
return;
}
//end of painting
public static int max(double[][] tab, int chromosomeCount)
{
double max = 0;
int k = 0;
for (int i = 0; i < chromosomeCount; i++)
{
if (max < tab[i][0])
{
max = tab[i][0];
k = i;
}
}
return k;
}
public static int[] mutation(int[] tab, int elem, int bit)
{
int mask = 1;
mask <<= bit;
tab[elem] = tab[elem] ^ mask;
return tab;
}
public static double[] crossing(double[] tab, double[] tab2, int p, int k)
{
double[] hold = new double[2 * k];
for (int i = 0; i < p; i++)
hold[i] = tab[i];
for (int i = p; i < 2 * k; i++)
hold[i] = tab2[i];
return hold;
}
//accomodation function, checks to which centre which point belongs based on distance
private static double accomodationFunction(double[][] klastry, double[][] testtab, int n, int k)
{
double Error = 0;
for (int i = 0; i < n; i++)
{
double min = 0;
int ktory = 0;
for (int j = 0; j < k; j++)
{
double dist = distance(klastry[j], testtab[i]);
if (j == 0)
{
min = dist;
}
if (min > dist)
{
min = dist;
ktory = j;
}
}
Error += min;
}
pom++;
return 1 / Error;
}
public static double distance(double[] tab, double[] tab2)
{
double dist = 0.0;
for (int i = 0; i < tab.GetLength(0); i++)
dist += Math.Pow(tab[i] - tab2[i], 2);
return dist;
}
}
The algorithm should work like so: (excuse me if not the best english)
1. Get random points (let's say 100)
2. Check into how many clusters we want to split them (the same thing I would do using k-means for example
3. Get starting population of chromosomes
4. Throu cutting on the roulette, crossing and mutation pick the best x centres, where x is the amount of clusters we want
5. Paint them.
Here are some results, and why I think it's wrong: (it's using 100 points, 5 clusters)
k-means:
lbg:
genetic(without colors now):
I hope this clarifies a bit.
I am trying to solve Gaussian elimination in c# using parallel-processing (in this case Parallel.For). My code is sometimes running fine and sometimes not.
I used as a starting point the code shown on the link: http://www.codeproject.com/Tips/388179/Linear-Equation-Solver-Gaussian-Elimination-Csharp .
I didn't use Parallel.For for back insertion just yet because there is problem with elimination.
Elimination Class:
public static bool Gauss(double[][] M)
{
int rowCount = (M.GetLength(0));
int temp = rowCount - 1;
//elimination
Parallel.For(0, temp, sourceRow =>
//for (int sourceRow = 0; sourceRow + 1 < rowCount; sourceRow++)//diagonal
{
for (int destRow = sourceRow + 1; destRow < rowCount; destRow++)//destination row
{
double df = M[sourceRow][sourceRow];
double sf = M[destRow][sourceRow];
for (int j = 0; j < rowCount + 1; j++) // line
{
M[destRow][j] = (M[destRow][j] * df - M[sourceRow][j] * sf) / df;
}
}
});
//back-insertion
for (int row = rowCount - 1; row >= 0; row--)
{
double f = M[row][row];
if (f == 0) return false;
for (int i = 0; i < rowCount + 1; i++) M[row][i] /= f;
for (int destRow = 0; destRow < row; destRow++)
{
M[destRow][rowCount] -= M[destRow][row] * M[row][rowCount];
M[destRow][row] = 0;
}
}
return true;
}
Generate Array:
public static double[][] GenerateArray2(int n)
{
Random rnd = new Random();
double[][] M = new double[n][];
for (int i = 0; i < n; i++)
{
M[i] = new double[n + 1]; // Create inner array
for (int j = 0; j < n + 1; j++)
M[i][j] = rnd.Next(-20, 20);
}
return M;
}
Print Array
public static string Print2(double[][] M)
{
string str = "";
int rowCount = M.GetUpperBound(0) + 1;
for (int row = 0; row < rowCount; row++)
{
for (int i = 0; i <= rowCount; i++)
{
str += M[row][i];
str += "\t";
}
str += Environment.NewLine;
}
return str;
}
Results are wrong in matrix 16x17 and up. At this point I don't know how to continue, I tried to lock M in elimination, didn't help.
Thanks for any help.
I am new to programming and I want my program to run a table consisting of stars(asterisks). E.g. table 4x3 has 4x3 stars. But my initial problem is that I do not know how to implement a multidimensional array in such a way that I just need to change the initial value of rows and columns in order to create more or less stars.
So: here is my code at the moment:
using System;
namespace ConsoleApplication1
{
class Multidimensional_array
{
static void Main(string[] args)
{
int arrayRows = 4;
int arrayCols = 3;
int[,] arrayTimes;
arrayTimes = new int [arrayRows, arrayCols];
//String star = "*";
for( int i = 0; i <= arrayRows; i++) {
for( int j = 0; j <= arrayCols; j++) {
//Console.WriteLine("*");
//arrayTimes[i, j] = Convert.ToInt32(Console.ReadLine());
}
}
Console.ReadLine();
}
}
}
So I just want that if I change the int arrayRows to 5 and int arrayCols to 5 then I receive a star table of 5x5. T
I think you're very close, you're just using the wrong data type for your array, haven't assigned the * to each position in said array, and your current code would give you an ArrayIndexOutOfBounds exception. You may have 4 rows and 3 columns, but array indices are zero-based, meaning when you access positions 1, 2, 3, etc. you use an index of 0, 1, 2, etc. respectively.
So, since you want to store the text "*", you should use a char[,] or a string[,] for your multi-dimensional array. I've chosen char[,] for this:
int arrayRows = 4;
int arrayCols = 3;
char[,] arrayTimes = new char[arrayRows, arrayCols];
const char star = '*';
// Set it up
for (int i = 0; i <= arrayRows - 1; i++)
{
for (int j = 0; j <= arrayCols - 1; j++)
{
arrayTimes[i, j] = star;
}
}
// Print it out
for (int i = 0; i <= arrayRows - 1; i++)
{
for (int j = 0; j <= arrayCols - 1; j++)
{
Console.Write(arrayTimes[i, j]);
}
Console.WriteLine();
}
Working ideone sample
Simple solution
static void Main(string[] args)
{
// Get the number of rows
Console.WriteLine("Enter the number of rows:");
int arrayRows = Convert.ToInt32(Console.ReadLine());
// Get the number of columns
Console.WriteLine("Enter the number of columns:");
int arrayCols = Convert.ToInt32(Console.ReadLine());
// For each item in the row
for (int i = 0; i < arrayRows; i++)
{
// For each item in the column
for (int j = 0; j < arrayCols; j++)
{
// Show a star
Console.Write("*");
}
// End the line
Console.WriteLine("");
}
// Read the line to stop the app from closing
Console.ReadLine();
}
If you want to store the stars
static void Main(string[] args)
{
// Get the number of rows
Console.WriteLine("Enter the number of rows:");
int arrayRows = Convert.ToInt32(Console.ReadLine());
// Get the number of columns
Console.WriteLine("Enter the number of columns:");
int arrayCols = Convert.ToInt32(Console.ReadLine());
// Create an array
char[,] arrayTimes = new char[arrayRows, arrayCols];
char star = '*';
// For each item in the row
for (int i = 0; i < arrayRows; i++)
{
// For each item in the column
for (int j = 0; j < arrayCols; j++)
{
// Show a star
arrayTimes[i, j] = star;
}
}
// Read the line to stop the app from closing
Console.ReadLine();
}
This do what you want,
int arrayRows = 2;
int arrayCols = 2;
char[,] arrayTimes;
arrayTimes = new char[arrayRows, arrayCols];
//String star = "*";
for (int i = 0; i < arrayRows; i++)
{
for (int j = 0; j < arrayCols; j++)
{
arrayTimes[i, j] = '*';
Console.Write("{0}",arrayTimes[i, j]);
}
Console.WriteLine();
}
Console.ReadKey();