Using Colors
Last updated
Last updated
Color adds another dimension in understanding your data. Within a single chart, color may provide a redundant encoding of information that is visible in other ways. ADVIZOR Charts use color in a single way across all charts, which often provides an important linkage.
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Color Mapping
Color is mapped to data tables. A table has a single coloring scheme. Each row in the table is assigned a color. Charts use this color when representing the data in that row. The easiest strategy is to map color using the values in a single field. The values in the field are ordered, a color scale (an ordered sequence of colors) is chosen, and colors are mapped to data values.
Categorical fields (e.g., strings) are ordered and colors assigned to each category in color scale order.
Continuous fields (e.g., numbers) have their range determined and this range is mapped to the color scale; data values are mapped to colors by finding the position of the data value in in the data range and using the corresponding position in the color scale.
In the examples below, a table is colored by a categorical field ("Sub-Type"). The Pie Chart is built using this field, so each of the slices in the pie is colored differently. The Histogram, on field "Volatility (%)", is on the same table so it is colored in the same way. In this case, the histogram is colored in bands corresponding to the "Sub-Type" values. This coloring is called "color stacking".
If these two charts were instead colored by "Volatility (%)" (the field the Histogram is based on), the result would look like this:
Now the Histogram is colored with a regular progression of colors, and the Pie Chart has color stacking. But again, the same data is colored in the same way. The black color represents ; note the missing values are shown in the histogram to the left of the plot. This did not occur in the original example because there were no missing values in the field being colored by, "Sub-Type".
Fields are mapped to colors by using the "Color Legend" "Field:" pull down box. The "Color Legend" is displayed by selecting the "Display Color Legend" button, on the toolbar, located in the upper right hand corner of the application. The "Show details.." link, must be selected to see the "Field:" pull down. The "Color Legend" is also displayed by selecting the "Display Color Legend" button, located on the Analyze or Author Ribbons. The "Show details.." link, must be selected to see the "Field:" pull down.
Color Scales
ADVIZOR Analyst provides predefined, ordered sets of colors. Here are the options:
Rainbow: is the default. Rainbow scales are best if you are coloring categorical data, but poor for coloring continuous data with magnitudes: how much bigger is "blue" than "green"? Adjacent values will have similar colors (until the transition between distinct hues occurs!), which may be difficult to distinguish.
Pastel and Equalized Pastel have similar characteristics as the rainbow scale. Since the colors are less saturated, they can be less jarring.
Gray and Thermal scales represent magnitudes better since there is a uniform progression of colors corresponding to the progression of values. The Thermal scale is modeled on the colors that metal goes through when heated, from black through yellow, red, and white.
Color scales are chosen bu selecting the "Scale" pull down, that is located on the "Color Legend". The "Color Legend" is displayed by selecting the "Display Color Legend" button, on the toolbar, located in the upper right hand corner of the application, and then selecting the "Show details.." link. The "Color Legend" is also displayed by selecting the "Display Color Legend" button, located on the Analyze or Author Ribbons. The "Show details.." link, must be selected to see the "Scale" pull down.
Colors and Removed Data When colors are applied to data, excluded values are ignored. So, for example, if data is removed and you recolor a table and later restore the removed data, it will be uncolored. To correct this, recolor the table by switching the "Color By" field to another field, then switching back to the original field.
Coloring by a continuous (numerical) field may have unexpected results. Colors are assigned equally to the total range of the field. If the data is highly skewed (for example, there are a small number of extreme values), then there may be large regions of the color scale for which there is no data. You can deal with this in two ways:
Remove the extreme data values and recolor by the same field.
Create a new field with the expression builder containing the rank of the data values, and color by this field. This field will have no gaps.
Chart Element Colors Chart elements have standard colors that are used. Chart elements include backgrounds, lines, mouse drag graphics, unselected color, selected color (if not mapped to data), missing values, and overplotting indicator. The color for any of these elements can be changed using "Select Chart Colors" form the "Tools" menu bar item.
See also:
The Red/green scale progresses from green (low) values to red (high).
Custom Color Mappings You may also define your own mapping of data field values to colors using the Color Workshop. Use the if the default field mapping are inappropriate for you data.
