讀取excel文件中指定全班分數表格，繪製各個成績區間累積人數的直方圖(Histogram)與整體數據的高斯分布，兩者做疊圖。

score_distribution.m

%% read file
clc, clear, close all
data = readmatrix('vlsi.xlsx'); % file name
score = data(1:86, 14); % extract score array

%% histogram plot
hold on;
grid on;
xlim([0,100]);
title('score distribution of VLSI circuit final exam','FontSize',15);
xlabel('score', 'FontSize',15);
ylabel('number of people','FontSize',15);
score_object = histogram(score,'FaceColor','#0072BD');
% score_object.BinWidth = 10; % interval between bars
counts = score_object.Values;
counts_height = score_object.BinEdges;
for n = 1:length(counts)
    text(counts_height(n) + 3.5,counts(n) + 1 ,num2str(counts(n)),'FontSize',20,'Color','#0072BD');
end

%% Gaussian distribution
std_s = std(score);
mean_s = mean(score);
x = 0:0.1:100;
r = normpdf(x,mean_s,std_s);
yyaxis right
plot(x,r,'LineWidth',2,'Color','#D95319')
set(gca,'YTickLabel',[]);

[max_value,max_index] = max(r);
plot(x(max_index),r(max_index),'.','MarkerSize',20,'Color','#7E2F8E');
hold off;

% %% ranking
% ranking = sort(score,'descend');
% prompt = "enter your score :";
% 
% while true
%     your_score = input(prompt);
%     number = find(ranking == your_score);
%     if isempty(number)
%         fprintf('\nThe score you entered is not in list\n');
%     else
%         fprintf('\n ranking : %d / %d (percentage : %.1f)\n',number(1), length(ranking),(number(1)/length(ranking))*100);
%     end
% end