1 files changed, 49 insertions, 0 deletions
diff --git a/260/CH13/EX13.7/13_7.sce b/260/CH13/EX13.7/13_7.sce
new file mode 100644
index 000000000..b9b1dec95
--- /dev/null
+++ b/260/CH13/EX13.7/13_7.sce
@@ -0,0 +1,49 @@
+//Eg-13.7
+//pg-537
+
+clear
+clc
+
+A = 0.9;
+B = 0.09;
+y(1) = 1;
+
+deff('out = func(in1,in2)','out = A*in2 - B*in2^2')
+
+h = 0.5;
+//Given the expression of analytical solution : y(t) = 10/(1+9*exp(-0.9*t))
+
+//The index again is 1-11 instead of 0-10
+
+for(i = 1:11)
+    
+    x(i) = 0 + (i-1)*h;
+    yex(i) = 10/(1+9*exp(-0.9*x(i)))
+end
+
+a = (2^0.5-1)/2;
+b = (2-2^0.5)/2;
+c = -(2^0.5)/2;
+d = 1 + (2^0.5)/2;
+
+printf('   x         yRKG       yExact\n')
+for(i = 1:10)
+    k1(i) = h*func(x(i),y(i));
+    k2(i) = h*func(x(i)+h/2,y(i)+k1(i)/2);
+    k3(i) = h*func(x(i)+h/2,y(i)+a*k1(i)+b*k2(i));
+    k4(i) = h*func(x(i)+h,y(i)+c*k2(i)+d*k3(i));
+    y(i+1) = y(i) + 1/6*(k1(i)+2*b*k2(i)+2*d*k3(i)+k4(i));
+    
+    printf('%f    %f    %f\n',x(i+1),y(i+1),yex(i+1))
+end
+
+printf('\nTherefore, it is observed that the RKG solution closely matches \nwith the analytical solution.\n')
+
+
+
+
+
+
+
+
+