In the latest version of gvSIG Online, a new type of symbology has been included: heatmap legend. This legend allows for the representation of either point density or weighted values through a continuous color gradient.

In the case of point density, it shows the areas where there are more points, which can be very useful to visualize where there are more streetlights in a municipality, where more accidents have happened, etc. In this case, all points have the same weight.

If a field is used for weighting, an example could be data collection stations, such as for temperature, pollution, etc., where the field to be weighted would correspond to those values.

Both types of legends support two gradient options: one in which the cold and warm colors are specified and a gradient is calculated between them, and another in which multiple colors and the percentage of each can be defined.

Other parameters that must be configured include the radius (in pixels), which should be calculated based on the distance between the points that are represented, and pixels per cell.

Additionally, if the layer is configured with a temporary parameter and this legend is applied, it is possible to visualize how the gradients change over time. For example, when displaying a crime layer, we could see whether the areas with the highest number of crimes have shifted over time.

You can see how it works in the following video: