Databases Reference
In-Depth Information
“OK”. Does seeing only “Condo/Townhome . . . ” make it easier to locate
their concentrations?
In the “Category” drop-down, select “none” to remove the category color
encoding.
Click on the “propertyType” category filter, then select “Reset”, to clear
the filter - once again seeing all observations.
Now look at employing color to encode numeric column values.
In the “Column” drop-down of the “Color Encoding” box select “price”.
The dots are color encoded to reflect home price. The darker and more
saturated the red, the higher the price. Can you see where the higher priced
homes are located?
To assist in locating the higher priced homes, filter out the lower to medium
priced homes.
Slowly slide the left end of the price filter to the right. Dragging the range
marker to the right filters out those homes whose price is lower than the
current position represented by the marker. Also as you drag, the range
displayed just above the slider is updated, letting you see exactly what
range of prices you are looking at. Drag the left slider up to about the
$500,000 price level. You probably won't be able to hit it exactly. What
patterns or relationships do you see with respect to price and location?
One problem when color encoding according to price is that a few extremely
high priced homes stretch out the full price range. This makes even million
dollar homes look relatively pale when encoded.
Eliminate all of the extremely high priced homes by dragging the left price
slider all the way to the left.
Drag the right slider down to about the $1,000,000 level.
Even though you are looking at homes ranging in price from $36,000 up to a
million dollars, they all look to be very similar in color, because the encoding is
still computed relative to the full dataset.
To correct this, click the “Relative to Range Filter” radio button. This color
encodes relative only to those homes falling within the current filter ranges.
Can you now see a pattern of generally higher prices in the north gradually
dropping as you head toward the south? Also notice higher prices on the
east, closer to the mountains.
