% MATLAB Tutorial - Nuclear Science and Engineering - Spring 2008 
% Instructor: Violeta Ivanova, violeta@mit.edu
% Faculty: Jacquelyn Yanch, jcyanch@mit.edu 

% EXERCISE 2 Correlation and Hypothesis Testing 

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% A. DATA IMPORT

% Import data on cigarette smoking and cancer mortality rates 
% per state from file CANCERSMOKING.dat.
% CIG:  Cigarettes [hundreds per capita] 
% Cancer deaths [per 100K population]: 
% BLAD: Bladder; LUNG: lung; KID: kidney; LEUK: Leukemia.
% Hint: Use Create Vectors from Columns in the Import Wizard. 


% Type WHO to confirm the vectors are created.
who

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% B. PLOTTING

% Plot the four cancer type mortality ratesand analyze in the Figure editor. 
% Hint: use markers with different colors (plot with no lines).

plot (CIG, BLAD, 'ro');
hold on
plot (CIG, LUNG, 'ko');
hold on
plot (CIG, KID, 'bo');
hold on
plot (CIG, LEUK, 'go');
hold off


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% C. CORRELATION COEFFICIENT

% Compute correlation coefficients between mortality rates and cigarette
% smoking and between the different cancers.
% Which correlations are significant within 95% confidence interval?
% Hint: Combine the data in a matrix first.

DATA = [CIG LUNG BLAD KID LEUK];
[R, P] = corrcoef(DATA);
[i, j] = find(P<0.05);
[i j]
R
P