Heat Map
Plots a heat map for a pair of attributes.
Signals
Inputs:
- Data
Input data set.
Outputs:
- None
Description
Heat map is a graphical method for visualizing frequencies in a two-way matrix by color. The higher the occurrence of a certain value, the darker the represented color. By combining two values on x and y axes we see where the attribute combination is the strongest and where the weakest, thus enabling us to find strong corelations or representative instances.
- Information on the input data
- Choose x attribute
- Choose y attribute
- Discrete attribute for color scheme
- Color scheme legend. You can select which attribute instances you wish to see in the visualization.
- Select the color scale strength (linear, square root or logarithmic)
- To move the map use Drag and to select data subset use Select
- Visualization
Example
Below you can see an example workflow for Heat Map widget. Notice that the widget only works with continuous data, so you need to first continuize data attributes that you want to visualize. Heat map below displays two attributes from Iris data set, namely the petal width and petal length. Here we can see the distribution of width and length values per Iris type. You can see that the variety Iris setosa is distinctly separated from the other two varieties by petal width and length and that the most typical values for these attributes is 0.2 for petal width and 1.5 for petal length. Iris virginica and Iris versicolor on the other hand have a greater variance of petal width and length values.