This is an example of interactive or "visual" optimization.
Sliding the slider above the heatmap adjusts the color-map scale for the heatmap display, relative to the current best computed value.
The sliders on the right control which pair of coordinates is plotted using the heatmap.
Click on the heatmap to update the current position along the 2 coordinates shown in the heat map.
Use the scroll-wheel while hovering over the heatmap to zoom in and out.
Dark green color shows the lowest known function value.
Clicking on dark green points until all pairs directions are in low-energy regions moves towards lower function values.
The colormap continually updates to show dark green as the current lowest known value.
Scanning through all dimension-pairs before making a move updates the color scale according to the current lowest known value.
Iteratevly Zooming in and shifting the colormap scale slider to the left refines optimal positions.
For this example, a four-particle Lennard-Jones cluster problem was used, with a known global minimum function value of -6.0 as shown in the thumbnail:
In principle, almost any objective function could be used, even one whose global minimum is not known.