Develop Reference

Read matrix elements in row wise

I am writing C# program for a matrix.when I enter matrix inputs from console, each element is coming in the separate row.But, I want to read row elements in a single line.
This is my code
Console.WriteLine("Enter the matrix");
int n= Convert.ToInt32(Console.ReadLine());
int[ , ] matrix=new int[n,n];
for(int i=0; i<n; i++){
for(int j=0; j<n; j++){
matrix[i,j]=Convert.ToInt32(Console.ReadLine());
// Console.Write("\t");
}
}
present I am getting like
1
2
3
4
But, I want like
1 2
3 4
Help me.

If you want to read one row in one line, you can ask user to enter space-separated values like 1 2, 3 4 and read like this
Console.WriteLine("Enter the matrix size");
int n = Convert.ToInt32(Console.ReadLine());
//add size and other validation if required
int[,] matrix = new int[n, n];
Console.WriteLine("Enter your values separated by space.");
for (int i = 0; i < n; i++)
{
var values = (Console.ReadLine().Split(' '));
for (int j = 0; j < n; j++)
{
matrix[i, j] = int.Parse(values[j]);
}
}
//to write
for (int i = 0; i < n; i++)
{
for (int j = 0; j < n; j++)
{
Console.Write(matrix[i, j] + " ");
}
Console.WriteLine();
}

You can enter the entire line and do the following:
for(int i=0; i<n; i++){
var input = Console.ReadLine().Split(' ').Select(t => int.Parse(t)).ToArray();
for (int j = 0 ; j < n ; j++){
matrix[i, j] = input[j];
}
}

Console.WriteLine("Enter the matrix");
int n= Convert.ToInt32(Console.ReadLine());
int[ , ] matrix=new int[n,n];
for(int i=0; i<n; i++){
string line = Console.ReadLine();
string[] elements = line.Split(' ');
for(int j=0; j<n || j < elements.Length; j++){
matrix[i,j]=Convert.ToInt32(elements[j]);
}
}

Please look same question
In your situation :
for(int i = 0; i < n; i++){
for(int j = 0; j < n; j + 2){
string input = Console.ReadLine();
string[] split = input.Split(' ');
int firstNumber = Int32.Parse(split[0]);
int secondNumber = Int32.Parse(split[1]);
matrix[i,j] = firstNumber ;
matrix[i,(j+1)] = secondNumber ;
}
}

C# program that returns morse code for numbers not working

I'm trying to make a program that: When given a 4 digit number (for example, 1001) it sums the digits of that number, for 1001 this is 1 + 0 + 0 + 1 = 2, than it finds all sequences of 6 numbers from 1 to 6 (including permutations, i.e. 1*1*1*1*1*2 is different than 2*1*1*1*1*1) whose product is that number.
The result should be printed on the console in the following format: each sequence of 6 numbers, with their Morse representation, separated with a single pipe: 1 is .---- , 2 is ..---: .----|.----|.----|.----|..---|, on a new row the next permutation: .----|.----|.----|..---|.----| and so on.
The problem is, my solution doesn't show the correct answers, not even the correct number of them.
Here's my code (and please, if possible, tell me where my mistake is, and not some one line hack solutions to the problem with LINQ and regex and God knows what):
string n = Console.ReadLine();
string[] digitsChar = new string[n.Length];
for (int i = 0; i < 4; i++)
{
digitsChar[i] = n[i].ToString();
}
int[] digits = new int[digitsChar.Length];
for (int i = 0; i < 4; i++)
{
digits[i] = Convert.ToInt32(digitsChar[i]);
}
int morseProduct = digits.Sum();
Console.WriteLine(morseProduct);
List<int> morseCodeNumbers = new List<int>();
for (int i = 1; i < 6; i++)
{
for (int j = 1; i < 6; i++)
{
for (int k = 1; i < 6; i++)
{
for (int l = 1; i < 6; i++)
{
for (int m = 1; i < 6; i++)
{
for (int o = 1; o < 6; o++)
{
int product = i * j * k * l * m * o;
if (product == morseProduct)
{
morseCodeNumbers.Add(i);
morseCodeNumbers.Add(j);
morseCodeNumbers.Add(k);
morseCodeNumbers.Add(l);
morseCodeNumbers.Add(m);
morseCodeNumbers.Add(o);
}
}
}
}
}
}
}
int numberOfNumbers = morseCodeNumbers.Count;
string[] morseCodes = new string[] { "-----", ".----", "..---", "...--", "....-", "....." };
for (int i = 0; i < numberOfNumbers; i++)
{
int counter = 0;
if (i % 5 == 0)
{
Console.WriteLine();
counter = 0;
}
if (counter < 5)
{
int index = morseCodeNumbers[i];
Console.Write(morseCodes[index] + "|");
counter++;
}

A lot of your for-loop conditions refer to i instead of j,k,l and m. The same for the increment part. For example:
for (int j = 1; i < 6; i++)
should be
for (int j = 1; j < 6; j++)
Furthermore if the range is from 1 to 6 you need to change < to <=, see:
for (int i = 1; i <= 6; i++)
You don't need to convert the string to a string array to get the int array of digits btw, so while this is correct:
for (int i = 0; i < 4; i++)
{
digitsChar[i] = n[i].ToString();
}
int[] digits = new int[digitsChar.Length];
for (int i = 0; i < 4; i++)
{
digits[i] = Convert.ToInt32(digitsChar[i]);
}
you could it do like that (sry for LINQ):
var digits = n.Select(c=>(int)char.GetNumericValue(c) ).ToArray();

How can I use hopfield network to learn more patterns?

Is there any relation between number of neurons and ability of Hopfield network to recognize patterns?
I write neural network program in C# to recognize patterns with Hopfield network. My network has 64 neurons. When I train network for 2 patterns, every things work nice and easy, but when I train network for more patterns, Hopfield can't find answer!
So, according to my code, how can I use Hopfield network to learn more patterns?
Should I make changes in this code?
There is my train() function:
public void Train(bool[,] pattern)
{
//N is number of rows in our square matrix
//Convert input pattern to bipolar
int[,] PatternBipolar = new int[N, N];
for (int i = 0; i < N; i++)
for (int j = 0; j < N; j++)
{
if (pattern[i, j] == true)
{
PatternBipolar[i, j] = 1;
}
else
{
PatternBipolar[i, j] = -1;
}
}
//convert to row matrix
int count1 = 0;
int[] RowMatrix = new int[(int)Math.Pow(N, 2)];
for (int j = 0; j < N; j++)
for (int i = 0; i < N; i++)
{
RowMatrix[count1] = PatternBipolar[i, j];
count1++;
}
//convert to column matrix
int count2 = 0;
int[] ColMatrix = new int[(int)Math.Pow(N, 2)];
for (int j = 0; j < N; j++)
for (int i = 0; i < N; i++)
{
ColMatrix[count2] = PatternBipolar[i, j];
count2++;
}
//multiplication
int[,] MultipliedMatrix = new int[(int)Math.Pow(N, 2), (int)Math.Pow(N, 2)];
for (int i = 0; i < (int)Math.Pow(N, 2); i++)
for (int j = 0; j < (int)Math.Pow(N, 2); j++)
{
MultipliedMatrix[i, j] = ColMatrix[i] * RowMatrix[j];
}
//cells in the northwest diagonal get set to zero
for (int i = 0; i < (int)Math.Pow(N, 2); i++)
MultipliedMatrix[i, i] = 0;
// WightMatrix + MultipliedMatrix
for (int i = 0; i < (int)Math.Pow(N, 2); i++)
for (int j = 0; j < (int)Math.Pow(N, 2); j++)
{
WeightMatrix[i, j] += MultipliedMatrix[i, j];
}
And there is Present() function (this function is used to return answer for a given pattern):
public void Present(bool[,] Pattern)
{
int[] output = new int[(int)(int)Math.Pow(N, 2)];
for (int j = 0; j < N; j++)
for (int i = 0; i < N; i++)
{
OutputShowMatrix[i, j] = 0;
}
//convert bool to binary
int[] PatternBinary = new int[(int)Math.Pow(N, 2)];
int count = 0;
for (int j = 0; j < N; j++)
for (int i = 0; i < N; i++)
{
if (Pattern[i, j] == true)
{
PatternBinary[count] = 1;
}
else
{
PatternBinary[count] = 0;
}
count++;
}
count = 0;
int activation = 0;
for (int j = 0; j < (int)Math.Pow(N, 2); j++)
{
for (int i = 0; i < (int)Math.Pow(N, 2); i++)
{
activation = activation + (PatternBinary[i] * WeightMatrix[i, j]);
}
if (activation > 0)
{
output[count] = 1;
}
else
{
output[count] = 0;
}
count++;
activation = 0;
}
count = 0;
for (int j = 0; j < N; j++)
for (int i = 0; i < N; i++)
{
OutputShowMatrix[i, j] = output[count++];
}
In below images I trained Hopfield for characters A and P and when input patterns are like A or P, network recognize them in true way
Then I train it for character C:
This is where every things go wrong!
Now if I enter pattern like C, this issue happen:
And if enter pattern like A, see what happen:
And if train more patterns, whole of grid become black!

I've spotted only one mistake in your code: you perform only one iteration of node value calculation, without verifying if the values have converged. I've fixed this method like this:
public bool[,] Present(bool[,] pattern)
{
bool[,] result = new bool[N, N];
int[] activation = new int[N * N];
int count = 0;
for (int i = 0; i < N; i++)
for (int j = 0; j < N; j++)
{
activation[count++] = pattern[i, j] ? 1 : 0;
}
bool convergence = false;
while (!convergence)
{
convergence = true;
var previousActivation = (int[])activation.Clone();
for (int i = 0; i < N * N; i++)
{
activation[i] = 0;
for (int j = 0; j < N * N; j++)
{
activation[i] += (previousActivation[j] * WeightMatrix[i, j]);
}
activation[i] = activation[i] > 0 ? 1 : 0;
if (activation[i] != previousActivation[i])
{
convergence = false;
}
}
}
count = 0;
for (int i = 0; i < N; i++)
for (int j = 0; j < N; j++)
{
result[i, j] = activation[count++] == 1;
}
return result;
}
This slightly improves the results, however probably should also be improved to calculate the values asynchronously to avoid cycles.
Unfortunately, this still introduces the behaviour you've described. This is results from the phenomena called spurious patterns. For the network to learn more than one pattern consider training it with a Hebb rule. You can read about the spurious patterns, stability and learning of the Hopfield network here and here.

To solve upside-down rendering?

I have written this segment of C# to help me understand how nested for loops can be used to render 2 dimensional data.
Here is what the output looks like.
████
███
██
█
I would like to make it so that the 4 blocks up top are rendered at the bottom, basically in the reverse order so that the steps ascend. However the console window only renders downward, so the conventional thinking won't be right. The following is my code.
static void Main(string[] args)
{
int i = 0;
int j = 0;
for (i = 0; i < 4; i++)
{
Console.Write('\n');
for (j = i; j < 4; j++)
{
Console.Write("█");
}
}
Console.ReadKey();
}
This is what I'd like the output to look like.
█
██
███
████

You need to reverse your loop condition from inremant to decremant..
for (i = 0; i < 4; i++)
{
Console.Write('\n');
for (j = i; j >= 0; j--)
{
Console.Write("█");
}
}
Output will be;
Here is a DEMO.
UPDATE: Since you change your mind, you need to add space every column (column number isi) 4 - 1 times.
public static void Main(string[] args)
{
int i = 0;
int j = 0;
for ( i = 0; i < 4; i++ )
{
for ( j = 0; j < 4; j++ )
{
if ( j < 3 - i )
Console.Write(" ");
else
Console.Write("█");
}
Console.Write('\n');
}
Console.ReadKey();
}
Here is a DEMO.

class Program
{
const int Dimension = 4;
static void Main(string[] args)
{
char[] blocks = new char[Dimension];
for (int j = 0; j < Dimension; j++)
blocks[j] = ' ';
for (int i = 0; i < Dimension; i++)
{
blocks[Dimension - i - 1] = '█';
for (int j = 0; j < Dimension; j++)
Console.Write(blocks[j]);
Console.WriteLine();
}
Console.ReadKey();
}
}

Should be:
for (j = 3 - i; j < 4; j++)
{
Console.Write("█");
}

The easiest way would be: just reverse your inner loop condition and decrement the counter instead of incrementing it:
for (i = 0; i < 4; i++)
{
Console.Write('\n');
for (j = i; j >= 0; j--)
{
Console.Write("█");
}
}
Console.ReadKey();
returning:
█
██
███
████
And for right-to-left version:
for (i = 0; i < 4; i++)
{
for(j = 0; j < 4; j++)
{
if(j < 3 - i)
Console.Write(" ");
else
Console.Write("█");
}
Console.Write('\n');
}
Console.ReadKey();
with a result:
█
██
███
████

Confused with realization of mathematical formula

Could you please help me with realization of mathematical formula in C#? Here it is:
R(t)=∑((x[i]-M)*(x[i+t]-M))
∑ goes from i=0 to N-t
M = const, t =[0,...,n], x is the vector with random data.
My implementation doesn't work correct and I don't know where the mistake is( I know, that I want you to do it for me, but I don't have anyone else to ask for help( Your help will be very appreciated! Thank you!
There is my code:
for (int i = 0; i < tvect.Lenght; i++)
{
sum[i] = 0;
t = tvect[i];
for (int j = 0; j < (N - t); j++)
{
sum[i] = sum[i] + (data[j] - M) * (data[j + t] - M);
}
}

float[] R(int[] t)
{
float[] sum = new float[t.length];
for (j=0;j<t.length;j++)
{
sum[j] = 0;
for (int i=0; i<N-t[j]; i++)
{
sum[j] += (x[i]-M)*(x[i+t[j]]-M);
}
}
return sum;
}

float sum = 0.0;
for(int j = 0; j < t.Length; j++) {
for(int i = 0; i < N - t[j]; i++) {
sum += (x[i]-M)*(x[i+t[j]]-M);
}
}