How to replace all the strings of a csv file with NaN using textscan and "TreatAsEmpty" ?

1 Ansicht (letzte 30 Tage)
I'm using textscan to read huge csv file.
Theses files contain numbers and strings.
How to replace all the string with NaN using "TreatAsEmpty" ?
The location of the strings depend on the file and the strings are different for each file.
For example a csv file like this :
1 3 5 6 temp 56 d 3
4 f 45 5 6 H 4 5
How to obtain that ?
1 3 5 6 NaN 56 NaN 3
4 NaN 45 5 6 NaN 4 5
Thank you for your help !
Best,
  1 Kommentar
dpb
dpb am 4 Mai 2017
Only way to do that with textscan would be to have a complete list of the strings contained in the file.

Melden Sie sich an, um zu kommentieren.

Antworten (1)

dpb
dpb am 4 Mai 2017
OTOH,
>> fid=fopen('ziad.txt');
>> fmt=repmat('%s',1,8);
>> c=textscan(fid,fmt,'collectoutput',1);
>> fid=fclose(fid);
>> data=str2double(c{:})
data =
1 3 5 6 NaN 56 NaN 3
4 NaN 45 5 6 NaN 4 5
>>
  2 Kommentare
Ziad Sliti
Ziad Sliti am 5 Mai 2017
Bearbeitet: Ziad Sliti am 5 Mai 2017
Hello,
Thank you for your answer.
But I work with big csv files (6000 rows 1000 columns) and it takes too many time to read all as string.
What about using "TreatasEmpty" option of textscan ?
dpb
dpb am 5 Mai 2017
Bearbeitet: dpb am 5 Mai 2017
That's not all that big; wouldn't think it too bad on time. What did it take?
As noted, you would have to have a complete list of all text fields in the file with an exact match for every one. Do you know that a priori?
I can't help but think even if did it wouldn't take quite a lot longer than the above.

Melden Sie sich an, um zu kommentieren.

Kategorien

Mehr zu Text Data Preparation finden Sie in Help Center und File Exchange

Produkte

Community Treasure Hunt

Find the treasures in MATLAB Central and discover how the community can help you!

Start Hunting!

Translated by