Databases Reference
In-Depth Information
Table 3.1
Missing Values Options
Column
Handling Option
Other
bathrooms
Predict
use bedrooms and sqFeet
bedrooms
Remove rows
cul-de-sac
Assign default
N
den
Assign default
N
diningRoom
Assign default
N
elementary
Assign default
leave blank
exterior
Remove column
garage
Remove column
jrHigh
Assign default
leave blank
laundry
Assign default
N
lot
Remove rows
mls
Remove column
neighborhood
Remove column
schoolDistrict
Predict
use zip
stories
Remove column
style
Remove column
Exploration using the location plot
Previously we used the boundary plot to evaluate measures tied to political
boundaries when we compared populations by state. In datasets visualized using
the boundary plot, there was one row or observation per boundary entity, even
though each observation may have contained multiple measure columns.
In this section, we review a related plot - the location plot. Each observation
represented in a location plot is a point on a map. To be viewable, the dataset
must contain latitude and longitude coordinates. The location plot is similar to a
scatter plot layered over a map background. The longitude and latitude values
are plotted along the X and Y axes respectively. VisMiner uses a server on the
Internet to generate the background map layer. In order to use the location plot,
an Internet connection is needed.
If you have not already done so, execute VisSlave on any computers to be
used for visualizations.
Drag the newly created CmpltHomes.csv dataset up to a display, release,
then select “Location Plot”.
A small dialog box opens, asking which column in the dataset contains the
observation's latitude and which contains the longitude. In this dataset the
latitude column is appropriately named “latitude” and the longitude
column “longitude”. Select these columns, then click “OK”.
