Alcuni comandi usati nella lezione del 1/10/2012


x = (0:1000)/1000*6-3
y = dnorm(x,0,1)
plot(x,y)


x = rnorm(100000,0,1)
hist(x,50)


x =rnorm(1000,10,10)
y =rnorm(1000,10,10)
cov(x,y)
cor(x,y)

plot(x,y)


x =rnorm(1000,10,10)
y = 1*x  + rnorm(1000,0,1)
plot(x,y)
cor(x,y)

x =rnorm(1000,10,10)
y = 0.01*x  + rnorm(1000,0,1)
plot(x,y)
cor(x,y)

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Z1 = rnorm(5000,0,1)
Z2 = rnorm(5000,0,1)
plot(Z1,Z2)

X1 = 2*Z1
X2 = 0.5*Z2
plot(X1,X2)


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teta= 1

X1 = cos(teta)*Z1 -sin(teta)*Z2
X2 = sin(teta)*Z1 +cos(teta)*Z2
plot(X1,X2)

-----------------------------------------

Z1 = rnorm(5000,0,1)
Z2 = rnorm(5000,0,1)
X1 = 2*Z1
X2 = 0.5*Z2

Y1 = cos(teta)*X1 -sin(teta)*X2
Y2 = sin(teta)*X1 +cos(teta)*X2

plot(Y1,Y2)