Skip to main content

THE DIRECTION THAT DOES NOT CHANGE DIRECTION

    

ADVT: SMART DOOR LOCK FROM AMAZON

The article has some math.  But it will be fun and exciting.

   Consider the point P(2,3) in the graph.  It has x-coordinate 2 and Y-coordinate 3.  We can draw an arrow mark from the origin to the point and call it a vector and represent it by (2,3).
     Multiply the vector by this matrix.
     The product yields a vector (-3,2).  Mark it in the graph.  Note, the original vector is rotated by 90 degrees.  A matrix can rotate, shear, scale, unshape a vector, or a point in the graph.  Hence this technique is widely used in computer graphics.
    Now consider the vector (0,0) or origin and multiply it by the same matrix.
[0  -1  *  [0      =  [0
1   0]        0]         0]

     The vector is not distributed.  That is, the origin cannot be rotated.  It is common sense but an important point.  We call this vector (0,0) as "eigenvector' of matrix [0 -1],[
1   0].
                                                             
"The eigenvector is one the direction of which cannot be changed by that matrix".The eigenvector of the matrix
 [-6  3     is  [1
   4  5]         4]           
 If you matrix-multiply both, you get(6, 24).  If you simply multiply (1,4) by 6, you get again (6, 24).  It confirms that the vector is simply 'scaled six times' but its direction remains the same.  You can mark them in a graph and find it is true.

The value 6 is called 'eigenvalue'. The eigenvalue is the scaling factor.

FINDING EIGEN VECTOR:
Also verifying the above case:

     Let (x,y) be an eigenvector of our matrix (-6,3
 4,5).  6 is the eigenvalue.
The principle:
Matrix *eigen vector = Eigen value * Eigen vector

Hence, (-6 3  *(x    = 6*(x
               4 5)     y)          y)
Matrix-multiplying, we get 2 equations:
     -6x+3y =6x
      4x +5y =6y
Rearranging:
  -12x +3y =0
   4x-1y =0
Solving we get, x =1 and y =4
or the eigenvector is (1,4),  We got it! The eigenvector principle vector is widely used in google search algorithms, computer graphics, statistics, etc.
                                                               

Comments

Popular posts from this blog

Your heart -you do not know

  Size and Location: The human heart is roughly the size of a clenched fist and is located slightly to the left of the center of the chest. Despite its relatively small size, the heart plays a crucial role in pumping blood throughout the entire body. Heartbeat Variability: The heart does not beat at a constant rate. The interval between heartbeats can vary, and this variability is considered a sign of a healthy heart. Factors such as breathing, emotions, and physical activity influence the heartbeat. Electrical Conduction: The heart's contractions are controlled by electrical impulses. The sinoatrial (SA) node, often called the "natural pacemaker," generates electrical signals that regulate the heartbeat and coordinate the pumping of blood. Blood Pumping Capacity: On average, the human heart pumps about 2,000 gallons (or 7,570 liters) of blood each day. Over a lifetime, this amounts to pumping enough blood to fill several Olympic-sized swimming pools. Heart Chambers and V...

THE WORK HORSE "="

    One cannot think of  a mathematical step without 'is equal to ' .  It balances right hand side and left hand side.  It aids simplification and manipulation of a mathematical expression. example: 2(A+B)  = C 2A+2B  = C         2A = C-2B           A = C-2B/ 2   In an electronic calculator,  the pressing of ' = " sign executes an asthmatic expression  or simply calculates.       In computer languages, it plays very important role.                                                                 A = B   When a computer looks at this expression, the value stored in the location named B is just transferred to the storage named A .  After execution both A and B will have the same value an...

How does your smart phone detect motion, steps, rotation, and location?

 How it works-1  An accelerometer in a smartphone is a microelectromechanical system (MEMS) device that measures acceleration and tilt. It works by detecting changes in motion by measuring the vibration or acceleration of the device. The accelerometer consists of a small mass suspended on a spring inside a sealed chamber. When the device is subjected to acceleration, the mass moves relative to the device, causing a change in capacitance that can be measured and processed by the smartphone's hardware. The accelerometer measures acceleration in three dimensions (x, y, and z) and provides data that the smartphone's software can use to determine the device's orientation, detect motion, and track changes in velocity and acceleration. The accelerometer is used for a variety of purposes in a smartphone, including screen rotation, motion tracking for games and fitness apps, and detecting the position of the device for navigation and location services. Additionally, it can be used t...