laborator probabilitati 3.12.2018

t <- seq(-5,5,0.001)
t1 <- seq(-3,7,0.001)

par(mfrow=c(2,2))

plot(t,dnorm(t,0,1),col="grey")
plot(t1,dnorm(t1,2,1),col="grey")
plot(t,dnorm(t,-2,1),col="grey")
plot(t,dnorm(t,6,1),col="grey")

plot(t,dnorm(t,0,1),col="grey",ylim = c(0,1),xlim=c(-10,10))
plot(t,dnorm(t,0,2),col="grey",ylim = c(0,1),xlim=c(-10,10))
plot(t,dnorm(t,0,3),col="grey",ylim = c(0,1),xlim=c(-10,10))
plot(t,dnorm(t,0,0.5),col="grey",ylim = c(0,1),xlim=c(-10,10))

#functia de repartitie
plot(t,pnorm(t,0,1),col="grey",ylim = c(0,1),xlim=c(-10,10))
plot(t,pnorm(t,0,2),col="grey",ylim = c(0,1),xlim=c(-10,10))
plot(t,pnorm(t,0,3),col="grey",ylim = c(0,1),xlim=c(-10,10))
plot(t,pnorm(t,0,0.5),col="grey",ylim = c(0,1),xlim=c(-10,10))

#functia de repartitie fi
par(mfrow=c(1,1))
y <- rep(0.5,10001)
plot(t,pnorm(t),col="blue",ylim=c(-4,4),xlim=c(-3,3))
#pentru a desena mai multe functii in acleasi reper:
lines(t,y,col="red") #sau si cu curves, dar atunci cand vrem sa hasuram
lines(t,simona(t))
simona  <- function(x)
{
  x^2-5
}