www.gusucode.com > stats 源码程序 matlab案例代码 > stats/ZScoresofTwoDataVectorsExample.m
%% Z-Scores of Two Data Vectors % Compute and plot the $z$-scores of two data vectors, and then compare % the results. %% % Load the sample data. load lawdata %% % Two variables load into the workspace: |gpa| and |lsat|. %% % Plot both variables on the same axes. plot([gpa,lsat]) legend('gpa','lsat','Location','East') %% % It is difficult to compare these two measures because they are on a very % different scale. %% % Plot the $z$-scores of |gpa| and |lsat| on the same axes. Zgpa = zscore(gpa); Zlsat = zscore(lsat); plot([Zgpa, Zlsat]) legend('gpa z-scores','lsat z-scores','Location','Northeast') %% % Now, you can see the relative performance of individuals with respect % to both their |gpa| and |lsat| results. For example, the third individual’s % |gpa| and |lsat| results are both one standard deviation below the sample % mean. The eleventh individual’s |gpa| is around the sample mean but has % an |lsat| score almost 1.25 standard deviations above the sample average. %% % Check the mean and standard deviation of the $z$-scores you created. mean([Zgpa,Zlsat]) %% std([Zgpa,Zlsat]) %% % By definition, $z$-scores of |gpa| and |lsat| have mean 0 and standard % deviation 1.