In this page, you will learn how to:
- What happens with missing
values (NAN) ?
- Where can I change the
parameters of preprocessing ?
- How can I filter my data ?
- Where can I see the
preprocessed data ?
Missing
Values
It
may happen, that you don't know all the evaluations of your actions.
These evaluations are missing and therefore called
missing values.
These values are indicated in your performance table by
NAN as
illustrated in the figure here below. However, the software can only
compute the results if he has all the evaluations. Therefore, before
computing the results, he will preprocess your data and remplace
missing values
by a
specific
number
that you can choose in the
Parameters
of Preprocessing.
This specific value can be a chosen value, the mean or the median of
the other actions for a specific criiterion. To choose this number, go
to
Parameters
of
Preprocessing.
Fig.1. Missing Values (
NAN)
are remplaced by some specific values, here the mean.
Parameters
of
Preprocessing
To
display
the menu with the parameters of
the preprocessing, go to Menu-->Data
Analysis --> Paraemeters Processing (see
Fig.2).
You will obtain
the frame displayed in Fig.3.
Fig
2. Access the
parameters of the Preprocessing.
Figure 3 display the parameters
for the preprocessing phase of the
data. So, if there are some
NAN
values, i.e.
missing values,
you can decide how to treat them. They can be replaced either:
- a specific value (tick the box
Val
and
enter a value)
- the mean of the other values on that criterion
- the median of the other values on that criterion.
Fig.
3: Parameters for the preprocessing of the missing values.
Filter
your data (Filtering)
You
may want to filter your data and select
for your analysis only a subset of the actions. That is called filtering.
You
will
therefore need to define the rule
which will filter your data. Besides, you can delete the actions or
just inactivate them.
For example, you may want to delete from your
actions, all the cars whose price is higher than 25000€ or you
may
want to desactivate them
while your analysing your problem.
To filter your data, access the parameters of the
Preprocessing; and you will find
the following frame:
To add a filter proceed as follows:
1. Click on Add
Filter
2.
Choose the criterion on which you want use to filter your
date (e.g.,
price).
3. Choose the constraint
(e.g., >=).4.
Choose a value
(e.g., 25000)
5. Choose your action: Delete or Inactivate the filtered actions.
(e.g., Delete actions).