Páginas

cuadratura de gauus


runge kutta cuarto orden


runge kutta segundo orden

clc
clear
f=inline('x-y')
x0=0;
y0=2;
xx=1;
n=4;
i=1;
h=(xx-x0)/n;
disp('-n-----x-------------y-----k0--------k1')
while i<=n
x1=x0+h;
k0=f(x0,y0);
k1=f(x0+h,y0+h*k0);
y1=y0+(h/2)*(k0+k1);
fprintf('\n%2i %10.5f %10.5f %10.5f %10.5f \n ',i,x1,y1,k0,k1)
y0=y1;
x0=x1;
i=i+1;
end
fprintf('\n y(1)= %2f\n ',y1)
clc
clear all

simpsom 1/3

clc
clear all
f=inline('(1/sqrt(2*pi))*exp((-x^2)/2)')

metodo del trapecio

clc
clear all
y=inline('1/x')
a=1;
b=2;
n=4;
x0=a;
h=(b-a)/4;
i=1;
s=0;
disp('-------x-------y---------integral')
while i<=n
x1=x0+h;
y0=y(x0);
y1=y(x1);
s=s+h*(y0+y1)/2;
fprintf('\n%10.5f %10.5f %10.5f \n ',x1,y1,s)
x0=x1;
i=i+1;
end

la 3

clc
clear all
v=[3.73 4.17 4.97 6.06 6.71 7.17 7.51 7.98 8.67 9.39 9.89]

la 5

clc
clear all
t=[293 300 320 340 360 380 400]
k=[8.53*10^-5 19.1*10^-5 1.56*10^-3 0.01 0.0522 0.2284 0.8631]


y=1.98*t.*log(k)
x=1.98*t
plot(x,y)
sol=polyfit(x,y,1)
z=exp(sol(1))
e=sol(2)
y1=1.98*t*log(z)-e
hold on
plot(x,y1,'o')

minimos cuadrados con polinomio de segundo grado

clc
clear all
disp('datos ingresados')
x=[280 650 1000 1200 1500 1700]
y=[32.7 453.4 52.15 53.7 52.9 50.3]
grid on
plot(x,y)
n=length(x);
a=[n sum(x) sum(x.^2)
sum(x) sum(x.^2) sum(x.^3)
sum(x.^2) sum(x.^3) sum(x.^4)];
b=[sum(y) sum(x.*y) sum(x.^2.*y)]';
c=inv(a)*b;
disp('la ecuacion es:')
fprintf(' %5.4f *x^2 + %5.4f * x + %5.4f\n ',c(3),c(2),c(1))
%comprobacion
sol=polyfit(x,y,2)
x1=x;
y1=c(3)*x.^2+c(2)*x+c(1);
hold on
plot(x1,y1,'o')

mìnimos cuadrados

clc
clear all
disp('datos ingresados')
x=[0 2 3 6 7]
y=[0.12 0.153 0.170 0.225 0.260]
n=length(x);
a=[n sum(x)
sum(x) sum(x.^2)];
b=[sum(y) sum(x.*y)]';
c=inv(a)*b;
disp('la ecuacion es:')
fprintf(' %5.4f *x + %5.4f\n ',c(2),c(1))
%comprobacion
polyfit(x,y,1);

euler modificado

clc
clear
f=inline('x-y')
x0=0;
y0=2;
xx=1;
n=4;
i=1;

metodo de euler normal

clc
clear
f=inline('x-y')
x0=0;
y0=2;
xx=1;
n=4;
i=1;
h=(xx-x0)/n;
disp('-n-----x-------------y--------pendiente')
while i<=n
x1=x0+h;
m=f(x0,y0);
y1=y0+m*h;
fprintf('\n%2i %10.5f %10.5f %10.5f \n ',i,x1,y1,m)
y0=y1;
x0=x1;
i=i+1;
end
fprintf('\n y(1)= %2f\n ',y1)

metodo de trapecio (integracion)

clc
clear all
y=inline('1/x')
a=1;
b=2;
n=4;
x0=a;
h=(b-a)/4;
i=1;
s=0;
disp('-------x-------y---------integral')
while i<=n
x1=x0+h;
y0=y(x0);
y1=y(x1);
s=s+h*(y0+y1)/2;
fprintf('%10.5f %10.5f %10.5f \n ',x1,y1,s)
x0=x1;
i=i+1;
end