how to import a file in MATLAB?
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Jesus
el 3 de Oct. de 2013
Respondida: Gautam PAL
el 16 de Oct. de 2013
I want to import a file (.dat or txt) in MATLAB, which contains numbers and NaN in some columns.
My file looks like this:
Name:
Day: 5/07/21998
UT LT hpp fpH SSP EF GG
0.0808 21.0808 227 - - N
0.1732 21.1732 300 4.7 340 - N
0.2533 21.2533 237 4.6 335 - N
0.3333 21.3333 249 - - N
0.4233 21.4233 251 - - N
0.5033 21.5033 244 4.6 328 - N
0.5833 21.5833 256 - - N
0.6733 21.6733 253 4.7 330 - N
2 comentarios
Walter Roberson
el 3 de Oct. de 2013
Do any values before the UT heading need to be imported? Which of the columns do you want read in? For example the EF column is shown here as always "-", but should that be skipped or read in? In the SSF column, should the blank entries be important as 0 or as NaN or should the column be imported as string without numeric interpretation?
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Nishitha Ayyalapu
el 14 de Oct. de 2013
Editada: Nishitha Ayyalapu
el 14 de Oct. de 2013
You could use
readtable
Lets say your data is in testdata.txt then following would create a table "T" with 7 columns, 8 rows and also saves column headers (UT, LT, hpp..etc).
to access UT column you would do
T.UT
However, with this approach fpH to hold all numeric data as float, the '-' entries are treated as empty and are recorded as nan.
T = readtable('testdata.txt','Delimiter','\t','HeaderLines',3,...
'TreatAsEmpty','-','Format','%f%f%f%f%f%s%s');
If fpH has to hold '-' entries and also the numeric data, fpH can be read as a string. But all the numeric data is also recorded as string
T = readtable('testdata.txt','Delimiter','\t','HeaderLines',3,...
'Format','%f%f%f%s%f%s%s');
3 comentarios
Walter Roberson
el 15 de Oct. de 2013
Editada: Walter Roberson
el 15 de Oct. de 2013
readtable() is very new. You can convert Nishitha's code as:
fid = fopen('testdata.txt', 'r');
T = textscan(fid, '%f%f%f%f%f%s%s', 'Delimiter','\t','HeaderLines',3,...
'TreatAsEmpty','-');
fclose(fid);
then the various columns are T{1}, T{2} and so on. But HeaderLines is perhaps 5 rather than 3.
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