how i can replace (99999,9) and (99,9900) in a column by NAN?

this file consists of 6 columns: the the third,the fourth,the fifth and the sixth include values such as (99999,9) and (99,9900) ; these values i want to replace them by the following word (NAN) not a number.....please tell me the code for doing this...........the name of the file is space......the name of the third column is y3......the name of the fourth column is y4........the name of the fifth column is y5......the name of the sixth column is y6.. i hope you tell me the code for replacing 99999,9 and 99,9900 by NAN (not a number).

[astrogeophysicist mohamed]

this file consists of 6 columns: the the third,the fourth,the fifth and the sixth include values such as (99999,9) and (99,9900) ; these values i want to replace them by the following word (NAN) not a number.....please tell me the code for doing this...........the name of the file is space......the name of the third column is y3......the name of the fourth column is y4........the name of the fifth column is y5......the name of the sixth column is y6.. i hope you tell me the code for replacing 99999,9 and 99,9900 by NAN (not a number).

Answer 1

[Cris LaPierre]

I'd use the function standardizeMissing.

% Create a row vector and replace all instances of -99 
% with the standard missing value for double data types, NaN.
A = [0 1 5 -99 8 3 4 -99 16];
B = standardizeMissing(A,-99)

[astrogeophysicist mohamed]

i did not understand, i want a direct code for replacing the following value (99999,9) and (99,9900) into (NAN) in column y3 which is the third column and y4which is the fourth column and y5 which is the fifth column and y6 which is the sixth column.

the 4 columns present in the following file (space.txt).

[Cris LaPierre]

Could you share your code for importing the data into MATLAB?

[astrogeophysicist mohamed]

space=load('space.txt');
y3=space(:,3);
y4=space(:,4);
y5=space(:,5);
y6=space(:,6);

[Cris LaPierre]

Does that work? I get an error message.

[astrogeophysicist mohamed]

yes it works , open the following photos

[Cris LaPierre]

You must be trimming the header lines out of your file. If I run that code on the space.txt file attached to this question, I get the following error message:

Error using load

Unable to read file 'space.txt'. Input must be a MAT-file or an ASCII file containing numeric data with same number of columns in each row.

[Cris LaPierre]

Once your data is in MATLAB, use standardizeMissing to replace the specified value with NaN. You'll need to do this for each variable. Here is the code for y3.

y3 = standardizeMissing(y3,99999.9);