%% Task 6.0
clear all
load deciles


%% Task 6.1

dec01_lt_0=sum(dec01<0)
dec10_lt_0=sum(dec10<0)

dec01_gteq_0=sum(dec01>=0)
dec10_gteq_0=sum(dec10>=0)

dec01_eq_0=sum(dec01==0)
dec10_eq_0=sum(dec10==0)


%% Task 6.2
dec01_and_dec10_lt_0=sum(dec01<0 & dec10<0)
dec01_and_dec10_gt_2std=sum(abs(dec01)>(2*std(dec01)) & abs(dec10)>(2*std(dec10)))


%% Task 6.3
dec01(dec01<0)
dec10(dec10<0)

dec01(dec01>=0)
dec10(dec10>=0)

dec01(dec01==0)
dec10(dec10==0)

dec01(dec01<0 & dec10<0)
dec10(dec01<0 & dec10<0)


%% Task 6.3
e=randn(100,1);
y=zeros(100,1);
y(1)=e(1);
for i=2:100
    y(i)=y(i-1)+e(i)+e(i)*(e(i)<0);
end
plot(y)


%% Task 6.5
find(dec05<0)
deciles=[dec01 dec02 dec03 dec04 dec05 dec06 dec07 dec08 dec09 dec10];
[i,j]=find(deciles<-0.02)


%% Task 6.6
all(deciles<0,2)
sum(all(deciles<0,2))
sum(any(deciles<0,2))
sum(~any(deciles<0,2))