How to replace -999 values with NaN in a Matlab table?

I have a Matlab table T1, with columns like the below:

T1.year
T1.month
T1.day
T1.var1
T1.var2
... 

Some of its columns are numerical and some of them are strings. For the numerical columns, there could be some -999 values in some of the columns to indicate NaN values.

Is it possible to replace all of the -999 values with NaN values, without specifying each of the columns?

I wish I could do someting as simple as that?

T1(T1==-999) = NaN

Like I do in a column data.

[Walter Roberson]

Are you reading from a text file? If so then use 'TreatAsMissing', '-999' option when you do the readtable()

[Leon]

Thanks for sharing that useful tip!

Unfortunately, I'm not reading from a text file. It is a carry-over Matlab table value.

Answer 1

[Steven Lord]

Use standardizeMissing.

t = array2table(magic(4));
t{2, 'Var3'} = -999
t2 = standardizeMissing(t, -999)

[Leon]

It works. Many thanks!

Answer 2

[Walter Roberson]

T1 = convertvars(T1, @isnumeric, @no999);

function x = no999(x)
  x(x==-999) = nan;
end

https://www.mathworks.com/help/matlab/ref/convertvars.html

[Leon]

Many thanks! This one works equally well.