Newton Raphson Method



In numerical analysis, Newton's method or NewtonRaphson method is named after Isaac Newton and Joseph Raphson. It is a method for finding successively better approximations to the roots or zeroes of a real-valued function.The method can also be extended to complex functions and to systems of equations.
The formula used is :
vj+1 = vj – f(vj)/f’(vj)

 Here we have used matlab to solve the circuit using Newton Raphson Method


Now the diode equation for current is,

i = (10)^ (-15) (e^38v-1)

Applying KCL at the node,

(v-0.1/2000) + i + (v/4000) = 0

 Substituting the value of i we get,

((v-0.1)/2000) + (10)^ (-15) (e^38v-1) +(v/4000) = 0

By Newton Raphson method Formula,

v^((j+1)) = v^((j)) - (6000v -400+8000*(10)^(-15) (e^38v-1))/(6000 +8000*38*(10)^(-15) (e^38v-1))


According to the code,
First the values of x and temp are compared and if they’re not equal, we enter the while loop,
The Newton Raphson method is applied therein, where
 num = f(vj)
den = f’(vj)
We observe that if the value of temp is way different from the answer expected then the program performs many iterations which is very inefficient.






- Rujuta Gokhale (17) and Sameeran Karpe (25)


Comments

  1. It's great blog, helped my understanding of this method and cleared concepts. Thank-you

    ReplyDelete
  2. What will happen with the plot with increasing iterations?

    ReplyDelete
    Replies
    1. The graph converges and provides better approximation

      Delete
  3. Is there any way in Matlab to differentiate the function?

    ReplyDelete

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