%
xrand=round(rand(3,7)*32);
indexes=find(xrand==20);
length(indexes)

%
xrand=round(rand(3,7)*32);
sum20=sum(xrand(:)==20);
disp(sum20)

%
count=0;
for i=1:3
   for j=1:7
    if xrand(i,j) == 20
        count=count+1
    end
   end
end

count=0;
for i=1:3
   for j=1:7
    switch xrand(i,j) 
        case 20
        count=count+1;
    end
   end
end
 
gender=[1 2 1]
grade=[1 2 3]
score=[80 70 95]
mentalhealth=zeros(300,3)
mentalhealth(:,1)=gender
mentalhealth(:,2)=grade
mentalhealth(:,3)=score
mentalhealthNew=sortrows(mentalhealth,[-1 2]);
disp(mentalhealthNew)

 MyInfo.name='Huang Xiangwen';
MyInfo.gender='male';
MyInfo.age=20;
MyInfo.hometown='Yichang';
MyInfo.hobby='chess'

OurInfo=struct('name',{'Huang Xiangwen','Wu Jieying','Wu Haiyan','Liang Xiaoqing'},'gender',{'male','male','female','female'},'age',{18 19 19 19},'hometown',{'Yichang','guangdong','ChengHai','MaoMing'},'hobby',{'chess','Playing guita','sleeping','sleeping'})


owngroup=struct('name',{'ZouYiZi','ChenJiaHuan','WangZiYu','ZhangYingDan'},'gender',{'female','male','male','female'},'age',{18,19,19,19},'hometown',{'Hunan','MaoMing','ChengHai','MaoMing'},'hobby',{'Sleeping','Playing guita','sleeping','sleeping'});
othergroup=struct('name',{'QiuYanMing','LuXiaoQiao','SuiYi','HuWei'},'gender',{1,2,1,2},'age',{20,19,19,19},'hometown',{'GuangdongMaoming','Guangdong','Jilin','Guangdong'},'hobby',{'singing','talking with other','listening music','none'});
ClassInfo=struct('owngroup',owngroup,'othergroup',othergroup)

mean([ClassInfo.owngroup.age ClassInfo.othergroup.age])
std([ClassInfo.owngroup.age,ClassInfo.othergroup.age],1)

line.width=5;line.style='-.';

line.color='r';

line.markershape='+';

line.markersize=10;

line.markerfacecolor=[0.7 0.6 0.4];

line.markeredgecolor=[0 1 0.5];
close all

x=0:8:100;

y=300-3*x+4;

p=plot(x,y);

set(p, 'Color', line.color,'LineStyle', line.style,'LineWidth', line.width,'Marker', line.markershape,'MarkerSize', line.markersize,'MarkerEdgeColor' , line.markeredgecolor, 'MarkerFaceColor', line.markerfacecolor);

 MyPsyCourse={'Mental Health Education for college students','Psychology History','General Psychology','Personality Psychology','Experimental Psychology','Social Psychology','Statistics of Psychology and Application of SPSS','Psychology experiment software application'};
disp(MyPsyCourse(7))

raw_score=112;
stand_score=CollegeIQ(raw_score);