cflu結構矩陣與異值矩陣

1、請先下載本週上課資料 點選左欄課程資料à 圖形使用者介面 下載第4週上課資料materials L4.zip，檔案大小約6.4MB 請先將Current Directory切換至materials_L4資料夾!CF結構矩陣與異值矩陣盧家鋒 助理教授.twCF10/9/2014 Lesson 4, ChiaFeng Lu110/9/2014 Lesson 4, ChiaFeng Lu2本週內容 異質矩陣 (cell array) 結構矩陣 (structure array)What can we store in an array? A=1:2:30; A

2、(9) A='Alvin' 'Lu' % Does it work? A='Alvin' 'Lu ' % Does it work? A='This is a test!' A(9)R2013b Can we store numbers and strings in an array? A=25000 'This is a test!' % Does it work? A=25000; 'This is a test!' % Does it work?CFCF10/9/2014 Le

3、sson 4, ChiaFeng Lu310/9/2014 Lesson 4, ChiaFeng Lu4Strings in an array List = 'David ' 'Andy% List =' 'Jay' 'Jolin ' 'Selina'DavidAndy Jay JolinSelinaCF異質矩陣cell arrayCF10/9/2014 Lesson 4, ChiaFeng Lu6Archive Big DatasetFor example, 30 normal controls vs. 30 p

4、atients with strokeCell Array Store different data formats in a single cell array. Numbers, strings, arrays Name, ID Age, gender, height, weight Pre-training data (8 x 450 values) Post-training data (8 x 450 values)à stringà numbersà number arrayà number array試試看在command window中鍵

5、入load('ExampleCell.mat')CFCF10/9/2014 Lesson 4, ChiaFeng Lu710/9/2014 Lesson 4, ChiaFeng Lu8c1c2c3c4c5c6r1Davidr2Andyr3Jayr4Jolinr5SelinaCreate a Cell array data= ; data=cell(4,1);Create a Cell array Different Ways data=cell(4,1);data(1)='NC01'data(2)=62; data(3)=rand(8,450);data(4)=

6、 16, '%task onset' data=cell(4,1); data1='NC01' data2=62; data3=rand(8,450); data4= 16, '%task onset'% string% number% number array% cell array data(1)='NC01' data(2)=62; data(3)=rand(8,450); data(4)= 16, '%task onset'% string% number% number array% cell array

7、% string% number% number array% cell array10/9/2014 Lesson 4, ChiaFeng LuCFCFUse variable viewer to check the data structure!10/9/2014 Lesson 4, ChiaFeng Lu910More Intuitive WayWhen dealing with different length of strings List = 'David ' 'Andy ' 'Jay ' 'Jolin ' '

8、Selina'Index of a cell array List = 'David' 'Andy' 'Jay' 'Jolin' 'Selina' Is there any difference between following two commands? List(1) List1à cell arrayà string List = 'David' 'Andy' 'Jay' 'Jolin' 'Selina

9、9;CFCF10/9/2014 Lesson 4, ChiaFeng Lu1110/9/2014 Lesson 4, ChiaFeng Lu12Useful Functions cell Create cell array iscell True for cell arrayIndex of a cell array A=rand(6,4),rand(5,7); Try it iscell(List(1) iscell(List1)A1,2(4,5)Navigation in variable viewer10/9/2014 Lesson 4, ChiaFeng LuCFCF10/9/2014

10、 Lesson 4, ChiaFeng Lu1314Index & Matrix OperationsConcatenation of Cell Arrays The same rule as usual.BAA1,1(2:4,2:3)+A1,2(2:4,5:6)A1,1(2:4,2:3)-A1,2(2:4,5:6)A1,1(2:4,2:3).*A1,2(2:4,5:6)A1,1(2:4,2:3)./A1,2(2:4,5:6)CFCF10/9/2014 Lesson 4, ChiaFeng Lu1510/9/2014 Lesson 4, ChiaFeng Lu16Archive Big

11、 DatasetFor example, 30 normal controls vs. 30 patients with stroke Name, ID Age, gender, height, weight Pre-training data (8 x 450 values) Post-training data (8 x 450 values)à stringà numbersà number arrayà number arrayCF結構矩陣structure array試試看在command window中鍵入load('ExampleS

12、truct.mat')CF10/9/2014 Lesson 4, ChiaFeng Lu1710/9/2014 Lesson 4, ChiaFeng Lu18Structure Array Store different data formats in a single structure array. Numbers, strings, arraysCell vs. Structure ArrayCFCF10/9/2014 Lesson 4, ChiaFeng Lu1910/9/2014 Lesson 4, ChiaFeng Lu20Structure of a Structure

13、ArrayCreate a Structure array ='NC01' data.age=62; data.predata=rand(8,450); data.notation= 16, '%task onset'% string% number% number array% cell arraydataa 1x3 structure arraysubject1subject2subject3name age, genderheight weight dataname age, genderheight weight dataname ag

14、e, genderheight weight data6 Fields for each subjectCFUse variable viewer to check the data structure! CF10/9/2014 Lesson 4, ChiaFeng Lu22Create a Structure array data(1).name='NC01'data(1).age=62; data(1).predata=rand(8,450); data(1).notation= 16, '%task onset' data(2).name='NC0

15、2' data(2).age=54;data(2).predata=rand(8,450);More Intuitive WayWhen dealing with different length of strings% string% number% number array% cell array% string% number% number array List = 'David ' 'Andy ' 'Jay' 'Jolin ' 'Selina' List(1).name = 'David&

16、#39; List(2).name = 'Andy' List(3).name = 'Jay' List(4).name = 'Jolin' List(5).name = 'Selina'data(2).notation= 23, '%task onset'% cell arrayUse variable viewer to check the data structure! CFCF10/9/2014 Lesson 4, ChiaFeng Lu2310/9/2014 Lesson 4, ChiaFeng Lu24

17、Index of a struct array Use both index and field name to specify data location.Index & Matrix Operationsdata(1).predate(2:5,3:4)+data(2).predate(4:7,4:5)data(1).predate(2:5,3:4)-data(2).predate(4:7,4:5)data(1).predate(2:5,3:4).*data(2).predate(4:7,4:5)CFdata(1).predate(2:5,3:4)./data(2).predate(

18、4C:7,4F:5)data(1).predate(6,3)Navigation in variable viewer10/9/2014 Lesson 4, ChiaFeng Lu2510/9/2014 Lesson 4, ChiaFeng Lu26Useful FunctionsBenefits for Using a Single Array Easy to clear, save, and loadstruct Create or convert to structure array S = struct('field1',VALUES1,'field2',VALUES2,.)isstruct True for structuresfields Display a list of fields in a structure arrayisfield True if field is in structure arrayrmfield Remove fields from a structure array10/9/2014 Lesson 4, ChiaFeng Lu Easy to make it a global variable global data global