[Numpy-discussion] difference between ma.masked and ma.masked_array?

[Timmie]

Hello,
what is the difference between ma.masked and ma.masked_array?

I am using this expression along with the scikit.timeseries:

series[(series.years>2000)&(series.years<2010)]=np.ma.masked

=> but now, my series does not get masked.

Rather the selected values (left part of the '=') get set to 0.0.

But if I use 

arr_masked = \
ma.masked_array(series, series[(series.years>2000)&(series.years<2010)])

the masked is applied sucessfully.

This is very strange. for some examples it works to use the firt method, for
others not.

Any hint is appreciated.

Thanks in advance,
Timmie