Ok so whats up with blogging anyway. No one reads this stuff and no one cares.
My friend has a blog (creativedevolution.com) and she draws pictures and she gets hundreds of hits a day. I wish I could draw like her.
Now I just sound like an idiot!
Archive for category Ramblings
Blah Blah Blah
Apr 5
Math Class
Oct 14
I’m taking a discrete math class. And I’m bored to tears.
Its not totally boring the first 10 mins of class are ok. That’s when I learn something new then the reset of the class is spent repeating the first 10 mins until everyone “gets it.” I can tell I’m not the only one; there are a few others as board as me.
Its not the teacher’s fault he actually makes this stuff interesting and is very good at explaining it at a level that my 10 year old could understand. Some people just don’t get it.
So here I am board with my laptop trying to look as if I’m paying attention and I get this bright idea. Make the computer do my homework for me. Yes I’ve written some code in C# that will calculate the properties of a relation of two sets. I started working on code to build the set but found out that it was already in the C# library so I scraped it.
Here is my Relation Class:
class Relation<T> : Set<Pair<T>>
{
private Set<T> _A;
private Set<T> _B;
public Relation(Set<T> A, Set<T> B)
{
_A = A;
_B = B;
}
public bool Add(T a, T b)
{
return Add(new Pair<T>(a, b));
}
new public bool Add(Pair<T> item)
{
if (_A.Contains(item.a) && _B.Contains(item.b))
{
return base.Add(item);
}
else
{
return false;
}
}
public bool IsReflexive()
{
IEnumerator<Pair<T>> ptr = GetEnumerator();
while (ptr.MoveNext())
{
Pair<T> op = ptr.Current;
if (!op.a.Equals(op.b))
{
return false;
}
}
return true;
}
public bool IsSymmetric()
{
IEnumerator<Pair<T>> ptr = GetEnumerator();
while (ptr.MoveNext())
{
Pair<T> op = ptr.Current;
if (!Contains(new Pair<T>(op.b, op.a)))
{
return false;
}
}
return true;
}
public bool IsAntisymmetric()
{
IEnumerator<Pair<T>> ptr = GetEnumerator();
while (ptr.MoveNext())
{
Pair<T> op = ptr.Current;
if (Contains(new Pair<T>(op.b, op.a)))
{
return false;
}
}
return true;
}
public bool IsTransitive()
{
IEnumerator<Pair<T>> ptr_x = GetEnumerator();
while (ptr_x.MoveNext())
{
Pair<T> x = ptr_x.Current;
IEnumerator<Pair<T>> ptr_y = GetEnumerator();
while (ptr_y.MoveNext())
{
Pair<T> y = ptr_y.Current;
if (x.b.Equals(y.a))
{
if (!Contains(new Pair<T>(x.a, y.b)))
{
return false;
}
}
}
}
return true;
}
public Set<T> SetA
{
get
{
return _A;
}
}
public Set<T> SetB
{
get
{
return _B;
}
}
public Matrix<bool> GetMatrix()
{
T[] A = _A.ToArray();
T[] B = _B.ToArray();
Matrix<bool> M = new Matrix<bool>(A.Length, B.Length);
Array.Sort(A);
Array.Sort(B);
for (int a = 0; a < A.Length; a++)
{
for (int b = 0; b < B.Length; b++)
{
if (Contains(new Pair<T>(A[a], B[b])))
{
M.Set(a, b, true);
}
else
{
M.Set(a, b, false);
}
}
}
return M;
}
}
I also created a Matrix Class
class Matrix<T> where T : struct
{
private int _rows;
private int _cols;
private T[,] _data;
public Matrix(int rows, int cols)
{
_rows = rows;
_cols = cols;
_data = new T[_rows, _cols];
}
public Matrix(T[,] data)
: this(data.GetLength(0), data.GetLength(1))
{
Set(data);
}
public void Set(T[,] data)
{
for (int r = 0; r < _rows; r++)
{
for (int c = 0; c < _cols; c++)
{
_data[r, c] = data[r, c];
}
}
}
public void Set(int row, int col, T value)
{
_data[row, col] = value;
}
public T Get(int row, int col)
{
return _data[row, col];
}
public Matrix<T> Join(Matrix<T> rhs)
{
if (!(default(T) is bool))
{
throw new Exception("join can only be used on the Boolean data type");
}
if ((_rows != rhs._rows) || (_cols != rhs._cols))
{
throw new Exception("both matrices have to be the same size");
}
Matrix<T> tmp = new Matrix<T>(rhs._rows, rhs._cols);
for (int r = 0; r < rhs._rows; r++)
{
for (int c = 0; c < rhs._cols; c++)
{
tmp.Set(r, c, (dynamic)this.Get(r, c) || (dynamic)rhs.Get(r, c));
}
}
return tmp;
}
public Matrix<T> Meet(Matrix<T> rhs)
{
if (!(default(T) is bool))
{
throw new Exception("meet can only be used on the Boolean data type");
}
Matrix<T> tmp = new Matrix<T>(rhs._rows, rhs._cols);
for (int r = 0; r < rhs._rows; r++)
{
for (int c = 0; c < rhs._cols; c++)
{
tmp.Set(r, c, (dynamic)this.Get(r, c) && (dynamic)rhs.Get(r, c));
}
}
return tmp;
}
public static Matrix<T> operator +(Matrix<T> lhs, Matrix<T> rhs)
{
if (default(T) is bool)
{
throw new Exception("join cannot be used on the Boolean data type");
}
if ((lhs._rows != rhs._rows) || (lhs._cols != rhs._cols))
{
throw new Exception("both matrices have to be the same size");
}
Matrix<T> tmp = new Matrix<T>(lhs._rows, lhs._cols);
for (int r = 0; r < lhs._rows; r++)
{
for (int c = 0; c < lhs._cols; c++)
{
tmp.Set(r, c, (dynamic)lhs.Get(r, c) + (dynamic)rhs.Get(r, c));
}
}
return tmp;
}
public static Matrix<T> operator -(Matrix<T> lhs, Matrix<T> rhs)
{
if (default(T) is bool)
{
throw new Exception("join cannot be used on the Boolean data type");
}
if ((lhs._rows != rhs._rows) || (lhs._cols != rhs._cols))
{
throw new Exception("both matrices have to be the same size");
}
Matrix<T> tmp = new Matrix<T>(lhs._rows, lhs._cols);
for (int r = 0; r < lhs._rows; r++)
{
for (int c = 0; c < lhs._cols; c++)
{
tmp.Set(r, c, (dynamic)lhs.Get(r, c) - (dynamic)rhs.Get(r, c));
}
}
return tmp;
}
public static Matrix<T> operator *(Matrix<T> lhs, Matrix<T> rhs)
{
if (lhs._cols != rhs._rows)
{
throw new Exception("matrices are not conformable; lhs columns has to equal rhs rows");
}
Matrix<T> tmp = new Matrix<T>(lhs._rows, rhs._cols);
for (int r = 0; r < lhs._rows; r++)
{
for (int c = 0; c < rhs._cols; c++)
{
dynamic value = default(T);
for (int x = 0; x < lhs._cols; x++)
{
if (value is bool)
{
value = value || ((dynamic)lhs.Get(r, x) && (dynamic)rhs.Get(x, c));
}
else
{
value = value + (dynamic)lhs.Get(r, x) * (dynamic)rhs.Get(x, c);
}
}
tmp.Set(r, c, value);
}
}
return tmp;
}
public static Matrix<T> operator *(Matrix<T> lhs, T rhs)
{
if (default(T) is bool)
{
throw new Exception("join cannot be used on the Boolean data type");
}
Matrix<T> tmp = new Matrix<T>(lhs._rows, lhs._cols);
for (int r = 0; r < lhs._rows; r++)
{
for (int c = 0; c < lhs._cols; c++)
{
tmp.Set(r, c, (dynamic)lhs.Get(r, c) * (dynamic)rhs);
}
}
return tmp;
}
public Matrix<T> Transpose()
{
Matrix<T> tmp = new Matrix<T>(this._cols, this._rows);
for (int r = 0; r < _rows; r++)
{
for (int c = 0; c < _cols; c++)
{
tmp.Set(c, r, Get(r, c));
}
}
return tmp;
}
override public String ToString()
{
String m = String.Empty;
for (int r = 0; r < _rows; r++)
{
if (r > 0)
{
m += "\n";
}
m += "[";
for (int c = 0; c < _cols; c++)
{
if (c > 0)
{
m += " ";
}
T value = Get(r, c);
if (value is bool)
{
m += (dynamic)value == true ? "1" : "0";
}
else
{
m += value.ToString();
}
}
m += "]";
}
return m;
}
}
Write?
Jul 3
If only I could write.
Words that is.
I’d have more interesting posts on this blog.
#include <iostream>
int main (int argc, char ** argv)
{
out << "Instead I'll just write some code." << std::endl;
return 0;
}
Happy 4th of July!
Double Rainbow
Apr 17
Dude it’s a double rainbow.
The Off Season
Mar 13
I love the beach this time of year. Its quiet, peaceful and there are no people. Don’t get me wrong I like people, especial the young attractive ones, but there is just something about walking on the beach with your best friend and no one else around to bug you. I also enjoy the waves crashing and the cold wind in my face. Ok maybe the cold wind is a but much but the waves are nice.
SNOW!
Feb 1
Did you know that it’s going to snow?
Snow Day, Again?
Jan 18
It’s not even February and we are already getting our second storm of the year. Last week we got over a foot of snow and I spent a good 4 hours clearing it from my driveway. Today we may get up to 6 more inches and then some freezing rain later tonight. Augggg!
iPod Touch Test
Jan 16
I bought myself an iPod touch with money I got for Christmas and my birthday. It’s pretty cool. It plays music and iPhone apps. I even downloaded an app to control my TiVo.
This is my fist blog post from my iPod. And most likely my last. I only seem to do things once. Oh well. 
First Post of 2011
Jan 15
This is going to be a short and sweet one but I’ve got to post something before January goes away.
If you have a mobile device you should try this site on it. I think you’ll like what what you see.
Christmas
Dec 25
Surprisingly we had a lot of gifts this Christmas.
Thank You Santa!
