主要總結了一下常用的表格操作:
創建一個表格table.csv,其內容是:
%讀取csv文件
T1=readtable('table.csv');
T1
%讀取不含列標題的csv文件
T2=readtable('table.csv','ReadVariableNames',false);
T2
%如果數據是被空格進行分隔的
%T = readtable(filename,'Delimiter',' ','ReadVariableNames',false)
% 讀取表行的名字
T3=readtable('table.csv','ReadVariableNames',false,'ReadRowNames',true);
% 表的基本操作(對於第一列其實是cell數組的操作)
T1.Var1
%注意區別以下兩個的區別
T1.Var1(1)
T1.Var1{1}
%% 表的基本讀取操作
%讀取特定列
T1.Alice
%讀取特定行(使用strcmp來選擇讀取哪一行)
disp('________________________________important________________________________');
find(strcmp(T1.Var1, 'two'))
%比如說讀取two那一行Alice的數據,是4
T1.Alice(find(strcmp(T1.Var1,'two')))
%find(T1.Var1=='one')
%T1.Alice(find(T1.Var1=='one'))
disp('________________________________end________________________________')
%% 檢測針對電子表格文件的導入選項,指定要導入的變量,然后讀取數據。
% 根據文件創建導入選項對象。
opts = detectImportOptions('table.csv')
opts.SelectedVariableNames = {'Alice'};
T4=readtable('table.csv',opts);%這里就只讀取了Alice的數據
T4
%% 表格的創建與保存
index=T1.Var1;
Alicemy=T1.Alice;
Bobmy=T1.Bob;
TT=table(index,Alicemy,Bobmy);
writetable(TT,'mytable.csv');
運行結果如下:
T1 =
2×4 table
Var1 Alice Bob Cindy
_______ _____ ___ _____
{'one'} 1 2 3
{'two'} 4 5 6
T2 =
2×4 table
Var1 Var2 Var3 Var4
_______ ____ ____ ____
{'one'} 1 2 3
{'two'} 4 5 6
ans =
2×1 cell 數組
{'one'}
{'two'}
ans =
1×1 cell 數組
{'one'}
ans =
'one'
ans =
1
4
________________________________important________________________________
ans =
2
ans =
4
________________________________end________________________________
opts =
DelimitedTextImportOptions - 屬性:
格式 屬性:
Delimiter: {','}
Whitespace: '\b\t '
LineEnding: {'\n' '\r' '\r\n'}
CommentStyle: {}
ConsecutiveDelimitersRule: 'split'
LeadingDelimitersRule: 'keep'
EmptyLineRule: 'skip'
Encoding: 'UTF-8'
替換 屬性:
MissingRule: 'fill'
ImportErrorRule: 'fill'
ExtraColumnsRule: 'addvars'
變量導入 屬性:
VariableNames: {'Var1', 'Alice', 'Bob' ... and 1 more}
VariableTypes: {'char', 'double', 'double' ... and 1 more}
SelectedVariableNames: {'Var1', 'Alice', 'Bob' ... and 1 more}
VariableOptions: Show all 4 VariableOptions
Access VariableOptions sub-properties using setvaropts/getvaropts
PreserveVariableNames: false
位置 屬性:
DataLines: [2 Inf]
VariableNamesLine: 1
RowNamesColumn: 0
VariableUnitsLine: 0
VariableDescriptionsLine: 0
要顯示該表的預覽,請使用 preview
T4 =
2×1 table
Alice
_____
1
4