数据分析1

源程序：
>>
a =
Columns 1 through 19
126 149 143 141 127 123 137 132 135 134 146 142 135 141 150 137 144 137 134
Columns 20 through 38
139 148 144 142 137 147 138 140 132 149 131 139 142 138 145 147 137 135 142
Columns 39 through 57
151 146 129 120 143 145 142 136 147 128 142 132 138 139 147 128 139 146 139
Columns 58 through 60
131 138 149
>>mean(a)
ans =
139
>>median(a)
ans =
139
>>var(a)
ans =
49.8983
>>std(a)
ans =
7.0639
>>skewness(a)
ans =
-0.4972
>> hist(a);title('杨婵201207020226')
>> normplot(a)；title('杨婵201207020226')
??? normplot(a)；title('杨婵201207020226')
|
Error: The input character is not valid in MATLAB statements or expressions.
>> normplot(a);title('杨婵201207020226')
>> qqplot(a);title('杨婵201207020226')
>>
直方图：
概率分布图：
QQ图：
三均值：
极差：
变异系数：
峰度：
茎叶图：
源程序：function stemleafplot(v,p)
% Plots stem and leaf plot to command window
%
% stemleafplot(v)
% stemleafplot(v,p)
%
% STEMLEAFPLOT plots stem-leaf plots of the input V to the command wi ndow.
% Leaf precision may be defined by the user. Note that inputs will be % rounded to the nearest leaf unit (
/wiki/Stemplot).
%
% INPUT
% V : Array of numerical inputs (NaN values are ignored)
%
% OPTION
% P : Leaf precision (defined as integer power of 10)
% Stem precision (by default) is 10^(P+1).
% P is automatically rounded at the beginning of the function. % Leaf and stem units are printed at the bottom of the graph. % Examples: P = -3 rounds V to the nearest 10^-3 = 0.001
% P = 3 rounds V to the nearest 10^3 = 1000
% [DEFAULT: P = 0]
%
% OUTPUT
% Command window output
%
% EXAMPLES
% % Stem-leaf plot of V with unit precision
% V = 10.*randn(1,50);
% stemleafplot(V)
%
% % Stem-leaf plot of V with precision of 0.1
% V = randn(1,50);
% stemleafplot(V,-1)
%
% % Stem-leaf plot of V with precision of 100
% V = 5000.*randn(1,50);
% stemleafplot(V,2)
%
% Jered Wells
% 01/28/2011
% jered [dot] wells [at] duke [dot] edu
%
% v1.2 (02/14/2012)
%
if ~isnumeric(v); error 'Input V must be numeric'; end
if ~exist('p','var'); p = 0; elseif isempty(p); p = 0; end
if ~isnumeric(p); error 'Input P must be an integer'; end
p = round(p);
% Condition V
v = v(~isnan(v));
v = v(:);
v = roundn(v,p);
% Organize stems and leaves
allstems = floor(v./10^(p+1));
allleaves = round(abs(v./10^p));
nstems = allstems(allstems<0)+1; % Negative stems
nstems = nstems(:);
pstems = allstems(~(allstems<0)); % Positive stems
pstems = pstems(:);
nleaves = allleaves(allstems<0); % Negative leaves
nleaves = nleaves(:);
pleaves = allleaves(~(allstems<0)); % Negative leaves
pleaves = pleaves(:);
dig = ceil(max(log10(abs(allstems))))+1; % Max # of digits in stem form = strcat(['%' num2str(dig+1) 'i']); % Format string for SPRIN TF
% Plot negative stems
if ~isempty(nstems)
for ii = min(nstems(:)):0
strstem = sprintf(form,ii);
if ii==0; strstem(end-1:end) = '-0'; end
strleaves = sprintf('%2i',mod(sort(nleaves(nstems==ii)),10)); s = strcat([strstem ' |' strleaves]);
disp(s)
end % NSTEMS
end % IF
% Plot positive stems
if ~isempty(pstems)
for ii = 0:max(pstems(:))
strstem = sprintf(form,ii);
strleaves = sprintf('%2i',mod(sort(pleaves(pstems==ii)),10)); s = strcat([strstem ' |' strleaves]);
disp(s)
end % PSTEMS
end % IF
% Print out key and units
form = strcat(['%.' num2str(max(0,-p)) 'f']);
s = strcat(['key: 36|5 = ' sprintf(form,36*10^(p+1)+5*10^p)]);
disp(s)
s = strcat(['stem unit: ' sprintf(form,10^(p+1))]);
disp(s)
s = strcat(['leaf unit: ' sprintf(form,10^p)]);
disp(s)
end % MAIN
截图结果：。