In each example, the starting vertex is located at a different position in factor space and the step sizes are adjusted accordingly. Other contractions and reflections move the vertexes toward the optimum. Collapse onto the optimum is straightforward. Unlike the initial simplexes in the previous two figures, this initial simplex does not contain the region of the optimum. Thus, after two contractions, a reflection, another contraction, and another reflection, the simplex finally envelops the optimum.
Further moves collapse the simplex onto the optimum.
Collapse onto the optimum is direct. In our experience, we have found the large initial variable-size simplex to be preferable for early research and development work, especially in projects in which there is very little prior knowledge. The simplex rapidly focuses the experimental effort into the region of the optimum. Authors, Frederick H. Walters, Lloyd R. Parker, Jr., Stephen L. Morgan and Stanley N. Deming.