## Median filtering

On this page, a median filter can be applied to a data channel of a data
table in order to smooth the data. Median filtering was not used in the
construction of the SEPEM
reference proton dataset.
Median filtering is performed by sliding a window (an interval of a
number of consecutive data points) over the data time series. For each
time window, the central value of the interval is replaced by the median
value in the interval: the middle value of the interval after sorting
the values in the interval in ascending order.

### Table and channel selection

Selecting a data table will reload the page with additional selection
and input options. Median filtering can only be applied to data tables
created by the current user.
Next, select a data channel and the interval half width *n* (each
data window will consist of the *n* values before and after the
central data point).

Then, press the `Run`

button to start the filtering process.
The values of the selected channel will be replaced in the database by
the smoothed values.

**Caution:** this operation is irreversible!

*Last modified on:* 2 October 2011.