How do I replace -1.0000e+30 with NaN?

I want to replace -1.0000e+30 in an array of SST and used the following but its not working why?:

data=netcdf.open('HadISST_sst1.nc','NC_NOWRITE')
time=netcdf.getVar(data,0);
time_bnds=netcdf.getVar(data,1);
lat=netcdf.getVar(data,2);
lon=netcdf.getVar(data,3);
sst=netcdf.getVar(data,4);
sst(sst==-1.0000*1e+30)=NaN;

Answer 1

[KSSV]

Let T be your array.

tol = -10^10 ; % fix this to satisfied value 
T(T<tol) = NaN ; 

[Simbarashe Chidzambwa]

Thank KSSV. It worked like a charm.

[KSSV]

Thanks is accepting/ voting the answer. :)

[Simbarashe Chidzambwa]

Thank you very much it worked.

Answer 2

[Steven Lord]

Since I'm guessing -1e30 is an outlier in your data you could use filloutliers. I'll use a slightly smaller outlier value for this example because it makes y display more nicely.

y = 1:10;
y(7) = 100

y = 1×10

1 2 3 4 5 6 100 8 9 10

y2 = filloutliers(y, NaN)

y2 = 1×10

1 2 3 4 5 6 NaN 8 9 10

[Simbarashe Chidzambwa]

Thank you very much Stephen, though the number represents missing values.

[Steven Lord]

You may be interested in standardizeMissing or fillmissing as well.