Analysing Optimisation Results

Available chart types

There are four tabs in the jEPlus+EA's GUI showing the progress of optimisation using different charts. The line charts shows the convergence of each objective with the progression of iterations. You can choose to show the minimum, the mean, the maximum, or the standard deviation of the objectives.

Line chart tab

The scatter plot tab shows all of the explored solutions, with those in the current population (blue) and on the current Pareto Front (red) marked. If you have more than two objectives, the chart shows a 2-D scatter view of the selected axes. Pointing the mouse cursor to any solution, the popup tool-tip will show its details.

Scatter plot tab

The distribution histograms of the design variable values in the know solutions are shown on the histogram tab. These charts can give you a quick view of how solutions are clustered and the sensitivity of the objective functions to the design variables.

Parameter value distributions

The table view tab provides an easy way to locate solutions and export data.

Solution table

Finding solutions on the scatter plot

The scatter plot view is where you can browse all explored solutions visually. Although you can have multiple (more than two) objectives in an optimisation project, the 2-dimensional chart can show only a flattened view. Controls are provided to help you find the solutions you want.

Scatter plot showing details of one solution

Select objectives to plot

You can select the objectives to be plotted on the x and y axis from the drop down list. From the shape of the scatter, correlation between objectives can be easily spotted.

Filtering solutions

A separate filter can be applied to each objective. Especially for the hidden objectives, defining a narrow range can give you the view of a slice of the multi-dimensional space.

Inspecting individual solutions

The scatter plot view supports a few actions that help inspect individual solutions using external tools. A single click on a solution will copy the path to either “in.idf” or “eplusout.eso” file to the clipboard. You can then switch to the external tool, such as the IDF editor, or xEsoView, and paste in the path in the file open dialogue.

If a double click on a solution is detected, the program will try to open either “in.idf” or “eplusout.eso” in the associated tool. Whether or not this will work depends on your system settings.

Adding images to tooltips

The model image shown in the popup tool-tip when the mouse cursor is pointing to a solution is a static image stored in a certain folder (“image/”) within the project folder. The image files must be named as 0.png, 1.png and so on, which correspond to sequence of the model files included in the project. The screenshot below shows the contents of the “image/” folder.

Image folder for tooltips

Sorting and exporting data

The table view tab allows you to browse solutions with detailed data, including values of parameters and objectives. You can use the context menu (right click menu) to inspect a selected solution. You can copy and paste data to other programs using Ctrl-C and Ctrl-V, and export the data to CSV or JSON files.

Context menu in table view