diff options
Diffstat (limited to '50/CH7/EX7.5/ex_7_5.sce')
-rwxr-xr-x | 50/CH7/EX7.5/ex_7_5.sce | 104 |
1 files changed, 52 insertions, 52 deletions
diff --git a/50/CH7/EX7.5/ex_7_5.sce b/50/CH7/EX7.5/ex_7_5.sce index 8d6eed3f7..dc8b9e584 100755 --- a/50/CH7/EX7.5/ex_7_5.sce +++ b/50/CH7/EX7.5/ex_7_5.sce @@ -1,52 +1,52 @@ -// example 7.5
-// solve the boundary value problem u''=u+x;
-// u(x=0)=u(0)=0; u(x=1)=u(4)=0; h=1/4;
-
-
-// we know; u''=(u(j-1)-2*u(j)+u(j+1))/h^2;
-
-// 1) second order method;
- x=0:1/4:1;
- u0=0;
- u4=0;
- u=[u0 u1 u2 u3 u4];
-// hence;
-disp('(u(j-1)-2*u(j)+u(j+1))/h^2=u(j)+x(j)') // for j=1,2,3;
-
-disp('for j=1 -16*u0+33*u1-16*u2=-.25')
-
-disp('for j=2 -16*u1+33*u2-16*u3=-.50')
-
-disp('for j=3 -16*u2+33*u3-16*u4=-.75')
-
-// hence solving for u1,u2,u3) ,
-u1=-.034885;
-u2=-.056326;
-u3=-.050037;
-
-disp(x);
-disp(u);
-
-// 2) numerov method;
- x=0:1/4:1;
- u0=0;
- u4=0;
- u=[u0 u1 u2 u3 u4];
-// since according to numerov method we get the following system of equations;
-disp('(191*u(j-1)-394*u(j)+191*u(j+1)=x(j-1)+10*x(j)+x(j+1)') // for j=1,2,3;
-
-disp('for j=1 191*u0-394*u1+191*u2=3')
-
-disp('for j=2 191*u1-394*u2+191*u3=6')
-
-disp('for j=3 191*u2-394*u3+191*u4=9')
-
-// hence solving for u1,u2,u3 ,
-u1=-.034885
-u2=-.056326
-u3=-.050037
-
-
-disp(x);
-disp(u);
-
+// example 7.5 +// solve the boundary value problem u''=u+x; +// u(x=0)=u(0)=0; u(x=1)=u(4)=0; h=1/4; + + +// we know; u''=(u(j-1)-2*u(j)+u(j+1))/h^2; + +// 1) second order method; + x=0:1/4:1; + u0=0; + u4=0; +u1_3 = rand(1,3) + u=[u0 u1_3 u4]; +// hence; +disp('(u(j-1)-2*u(j)+u(j+1))/h^2=u(j)+x(j)') // for j=1,2,3; + +disp('for j=1 -16*u0+33*u1-16*u2=-.25') + +disp('for j=2 -16*u1+33*u2-16*u3=-.50') + +disp('for j=3 -16*u2+33*u3-16*u4=-.75') + +// hence solving for u1,u2,u3) , +u1=-.034885; +u2=-.056326; +u3=-.050037; + +disp(x); +disp(u); + +// 2) numerov method; + x=0:1/4:1; + u0=0; + u4=0; + u=[u0 u1 u2 u3 u4]; +// since according to numerov method we get the following system of equations; +disp('(191*u(j-1)-394*u(j)+191*u(j+1)=x(j-1)+10*x(j)+x(j+1)') // for j=1,2,3; + +disp('for j=1 191*u0-394*u1+191*u2=3') + +disp('for j=2 191*u1-394*u2+191*u3=6') + +disp('for j=3 191*u2-394*u3+191*u4=9') + +// hence solving for u1,u2,u3 , +u1=-.034885 +u2=-.056326 +u3=-.050037 + + +disp(x); +disp(u);
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