initial commit / add all books

1 files changed, 35 insertions, 0 deletions

diff --git a/191/CH4/EX4.9/Example4_9.sce b/191/CH4/EX4.9/Example4_9.sce
new file mode 100755
index 000000000..058788449
--- /dev/null
+++ b/191/CH4/EX4.9/Example4_9.sce
@@ -0,0 +1,35 @@
+//Given's Method

+//reduce A1 to tridiagonal form

+clc;

+clear;

+close();

+format('v',7);

+A1 = [2 -1 1 4;-1 3 1 2;1 1 5 -3;4 2 -3 6];

+disp(A1,'A = ')

+// zero is created at (1,3)

+//by taking the rotation matrix X1=[c 0 s; 0 1 0;-s 0 c]; where c=cos and s=sin

+//O is theta

+

+count =0;

+for i=1:(4-2)

+    for j=i+2:4

+        if abs(A1(i,j))>0 then

+            p=i+1;q=j;

+            O = -atan(A1(p-1,q)/(A1(p-1,p)));

+            c = cos(O);

+            s = sin(O);

+            X = eye(4,4);

+            X(p,p)=c;

+            X(q,q)=c;

+            X(p,q)=s;

+            X(q,p)=-s;

+            

+            A1 = X'*A1*X;  

+            disp(A1, 'Ai = ');

+            disp(X ,'X = ');

+            disp(O, 'Theta = ');

+            count = count+1;

+        end

+    end

+end

+disp(A1,'Reduced A1 to trigonal matrix is : ')
\ No newline at end of file