read certain rows and lines into array from txt file

Question

smalltony 2019-10-23

0
链接

此问题的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/486992-read-certain-rows-and-lines-into-array-from-txt-file

回答： dpb 2019-10-23

i need to read the numbers in the columns and rows from a text file with a number of header lines and end lines into an array

some header lines (10 odd)
S,Sweep No,	N,Test No,	L,Length,	A,Act Length,	S,Start Time,	E,End Time,	T1,Transition 1,	T2,Transition 2,	O,Outcome
S,0,	N,0,	L,156998,	A,156998,	S,7672055,	E,7829053,	T1,7672056,	T2,7672056,	O,0
S,0,	N,1,	L,156998,	A,156998,	S,7972052,	E,8129050,	T1,7974053,	T2,7974053,	O,0
S,0,	N,2,	L,156998,	A,156998,	S,8272048,	E,8429046,	T1,8276049,	T2,8276049,	O,0
S,0,	N,3,	L,156998,	A,156998,	S,8572044,	E,8729042,	T1,8578045,	T2,8578045,	O,0
S,0,	N,4,	L,156998,	A,156998,	S,8872041,	E,9029039,	T1,8880042,	T2,8880042,	O,0
S,0,	N,5,	L,156998,	A,156998,	S,9172037,	E,9329035,	T1,9182038,	T2,9182038,	O,0
S,0,	N,6,	L,156998,	A,156998,	S,9472034,	E,9629032,	T1,9484035,	T2,9484035,	O,0
S,0,	N,7,	L,156998,	A,156998,	S,9772030,	E,9929028,	T1,9786031,	T2,9786031,	O,0
End of Test 
some end lines (a couple)

example of array:

0	99998	99999	8361007	8461006	8361008	8361008	0
1	99998	99998	8561005	8661003	8571006	8571006	0
2	99998	99999	8761002	8861001	8781003	8781003	0
3	99998	99998	8961000	9060998	8991001	8991001	0
4	99998	99999	9160997	9260996	9200998	9200998	1
6	99998	99999	9560992	9660991	9620993	9620993	0
7	99998	99998	9760990	9860988	9830991	9830991	0

the number of rows will be different depending on the text file but the format of the data i need will be the same

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smalltony 2019-10-23

How would I get rid of the bottom text that i don't need

dpb 2019-10-23

编辑：dpb 2019-10-23

Tell the import object to not fill in the rows w/ missing data.

Or, if don't do that, will return rows consisting all of NaN values that can be deleted.

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Answer 1

dpb 2019-10-23

0
链接

此回答的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/486992-read-certain-rows-and-lines-into-array-from-txt-file#answer_397960

在 MATLAB Online 中打开

opt=detectImportOptions('smtony.txt');                          % get the base import object
opt.SelectedVariableNames=opt.SelectedVariableNames(2:2:end);   % tell it only want numeric columns (every other one)
opt.MissingRule='omitrow';                                      % don't fill missing variables, skip instead

The above on the sample file returns:

>> t=readtable('smtony.txt',opt)
t =
  8×9 table
    SweepNo    TestNo     Length     ActLength    StartTime      EndTime      Transition1    Transition2    Outcome
    _______    ______    ________    _________    __________    __________    ___________    ___________    _______
    0          0         1.57e+05    1.57e+05     7.6721e+06    7.8291e+06    7.6721e+06     7.6721e+06     0      
    0          1         1.57e+05    1.57e+05     7.9721e+06    8.1291e+06    7.9741e+06     7.9741e+06     0      
    0          2         1.57e+05    1.57e+05      8.272e+06     8.429e+06     8.276e+06      8.276e+06     0      
    0          3         1.57e+05    1.57e+05      8.572e+06     8.729e+06     8.578e+06      8.578e+06     0      
    0          4         1.57e+05    1.57e+05      8.872e+06     9.029e+06      8.88e+06       8.88e+06     0      
    0          5         1.57e+05    1.57e+05      9.172e+06     9.329e+06     9.182e+06      9.182e+06     0      
    0          6         1.57e+05    1.57e+05      9.472e+06     9.629e+06     9.484e+06      9.484e+06     0      
    0          7         1.57e+05    1.57e+05      9.772e+06     9.929e+06     9.786e+06      9.786e+06     0      
>> 