- After clustering, individual vertices can be assigned to another cluster.
- Interaction between the ‘Info’ tab of the Palette window and the canvas has been improved: more options in the ‘contextual menus’ and higher reactivity.
- The ‘self-loops’ (an edge connecting a vertex to itself) of a graph can be selected in the canvas as a group and displayed in the ‘Info’ tab (and removed individually or as a group).
- Drawing in the canvas has been improved: stronger anti-aliasing, no red shine on an edge after deselecting, and an optimized refreshing.
- Isolated vertices and leaf vertices containing a self-loop were not always recognized as isolated or leaf vertices, respectively. Isolated vertices with a self-loop were erroneously recognized as leaf vertices. Now all isolated and leaf vertices are recognized correctly.
- A cluster algorithm based on ‘Random walk’ is added. This clustering algorithm provides an additional tool to identify clusters of vertices in a graph. Palette window -> tab ‘Calculate’ -> Section ‘Graph clustering’
- In the ‘Info’ tab, the vertices and edges can always be selected (even if they are shown as a result of a calculation).
- Drawing a graph and organizing the graph into groups and clusters has been further optimized: in the past some drawing combinations were not possible.
- In a ‘random walk’ without a ‘predefined’ end vertex, the weight of the edges can be included in the calculations.
- The random walk algorithm has been improved (better coverage of the graph).
- Occasionally in a random walk, a vertex could be visited twice in a row or an unconnected vertex could be added to the walk.
- In version 2.0.8 selected vertices in the canvas could not be deselected individually by clicking in the selected vertex.
- The ability to perform a ‘Random walk’ with various options has been added to the graph analysis tools (Palette window -> Calculate tab -> section ‘Paths and flows’).
- When edges are selected in the ‘Info’ tab, only the edges are selected in the graph and not the edges with their connection vertices as before. This allows to remove only the edges and not the connecting vertices.
- Opening files can be stopped by pressing the ‘ESC’ button.
- Better canvas responsiveness when drawing large charts. When the graph contains more than 10,000 edges, mouse drag selection is blocked: the response time is too slow to be useful and slows down the overall responsiveness of the application.
- Improved overall memory management.
- In version 2.0.6, calculating the s-t minimum cut and the global minimum cut of graphs with less than 7 vertices resulted in an application crash.
- In the previous versions, multiple selection of vertices or edges in the ‘Info’ tab could crash the application in specific cases.
- When the graph was undirected and the edge weight was changed in the ‘Layout tab’ of the Palette window, only one of the directions of the edge was changed in previous versions. This bug is fixed and now the weights of both directions of the edge are changed simultaneously: the weight of the other direction is set to the weight of the direction being changed.
- In the previous version, the smallest global minimum cut was not always shown. This error has been fixed.
- The calculation of the ‘s-t minimum cut’ has been optimized and expanded. The possibility is included to select the minimum cut with the fewest edges or the minimum cut that divides the graph into two parts with as equal a number of vertices as possible.
- In the calculation of the global minimum cut, the option is included to omit the leaf vertices, and any newly formed leaf vertices, from the calculation. When the graph contains leaf vertices, the global minimum cut often contains an edge connecting a leaf vertex to the graph. Omitting the leaf vertices from the calculation leads to a a more meaningful result.
- If a larger graph contains edges with negative weight and negative cycles can be formed, the shortest path calculation is still an approximation, but in most cases the shortest path calculated is close to the correct solution.
- If a graph contains edges with negative weight, the longest path calculation is still an approximation, but in most cases the longest path calculated is close to the correct solution.
- The interactions with the ‘palette window’ have been further optimized, such as scrolling and starting calculations.
Bug fixes: for the Windows version
- A mouse click in the canvas while drawing or clustering will no longer crash the application.
- Clicking the ‘Calculating centrality’ or ‘Identify clusters’ pushbuttons in the ‘Calculate’ tab of the Palette window will not cause the scrollbar (and consequently the tab panel) to jump to its ‘start position’.
- Categories (classes) can be created and assigned to the vertices.
- The vertices can be drawn according to the categorization and grouped in the graph by category.
- The content and the category of the vertices can be imported from a spreadsheet.
- The ‘Info’ tab contains a search function.
- In the previous version, the ‘Color picker’ on MacOS ‘Big Sur’ was slow and had to be closed to insert the selected color. This item has been fixed and the ‘Color picker’ is now fully functional in the application.
- In previous versions, an error message sometimes appeared after the application was closed. DiscretePath will now close without giving an error.
- When clustering with organizing the graph by clusters and there was only one cluster, an error message was displayed and the canvas was emptied (this could be undone by using the Undo/Redo function). This item has been fixed: no error and canvas not emptied.
- In the ‘Info’ tab, the properties of the graph could not be shown (“Summary of graph properties”) if new vertices or edges have been added and the graph was not drawn or saved. This bug has been fixed and the properties of the graph can be viewed in the ‘Info’-tab while constructing the graph.
- For MacOS: The downloaded application contains the Apple technology called Universal Binary. A Universal Binary application looks the same as a regular application, but contains one version of the application that can run on x86-64 (Intel 64-bit) and another that can run on Apple Silicon.
- The number format used in the application is independent of the number separators as set in System Preferences. Data being imported is converted to the number format used in the application (US English). The number format of the data being exported is as set in System Preferences. In this way, the application works robustly on systems that use different number separators.
- Scientific notation caused problems with some combinations of number separators as set in the System Preferences. This item is resolved by implementing the improvement as explained above.
- The calculation of the maximum flow in a graph taking into account both the capacities of the edges and the vertices has been added.
- The current algorithms for maximum flow, minimum s-t cut, global minimum cut, and minimum spanning tree have been optimized.
- Memory management is optimized for both drawing and analyzing graphs.
- Maximum flow and minimum cut calculations: if the chart contains multiple cycles, it could result in infinite loops in the previous versions. These algorithms have been modified to handle complex multi-cycle graphs.
- Calculation of the global minimum cut: when the graph consists of several subgraphs and the first subgraphs have no global minimum cut, the application crashed in the previous versions. This bug has been fixed.
- The orientation of an edge can be correctly switched using the text fields in the “Edges” box of the “Layout” tab.
- The scaling of the length of the edges in the “Preferences” window is now more accurate.
- The preferences can be reset to the default values and a damaged preferences file can be deleted and replaced with a new preferences file with the default values: “Help” menu -> “Restore preferences …”.
- “.gdp” files can be opened from the “Finder”.
- The number format is standardized throughout the application: “.” is the decimal separator – no thousands separator – exponential notation is used for readability
- When the application is opened in MacOS, the top of the windows (the window with the canvas and the palette window) will be placed below the menu bar (adapted to “Big Sur”)
- The correct total minimum cut and the length of the longest path are displayed.
- The drawing of edges as curves has been optimized (layout and drawing efficiency).
- The direction of an edge can now be indicated by an arrow or a dot (circle). For complex graphs the dot indication is clearer and drawing is more efficient.
- Random graph building has been significantly improved: especially when the graph is saturated with edges (versus the number of vertices).
- The value of the sliders can now be set by scrolling the mouse. This makes it easier to set an exact value.
- Under the hood, some major adjustments have been made to make graph drawing better and more efficient.
- When calculations are started, the graph zoom is set to “1” to avoid screen flickering.
- Printing is enabled. This was an item in some of the previous MacOS versions.
Major adjustments have been made to change the layout of graph-specific default vertices and edges.
- In the window to set the preferences (menu “Preferences”), the changes made to the layout of the default edges have been made more visual.
- The changes made to the graph-specific layout of the default vertices and edges (“Layout panel”, sections “Vertices” and “Edges”, button “Show all layouts”) are made more visual.
- The layout of multiple graph-specific default vertices and edges can be changed without the need to close the window to save the layout for each default vertex or edge. In previous versions, only one default vertex or edge could be changed at a time, after which the window had to be closed.
- Setting the graph-specific default layouts of the vertices and edges was not always clear and could lead to misinterpretations and, consequently, unwanted vertex and edge layouts. This is now addressed in the “improvements” outlined above.
- The option is available to display grid lines in the canvas. This is to support the manual drawing of a graph (menu “View”, submenu “Show grid lines”).
- More vertex shapes are available: ovals, rectangles, pentagons, hexagons, heptagons, and stars.
- When changing the width, height, color or shape of a vertex (or a group of vertices), the changes are displayed in real time: in the canvas, in the window to set the default layout of the vertices of the current graph, and in the window to set the preferences.
- The number format is uniform throughout the application.
- If the graph contains only one edge and this edge has been removed, “Undo / Redo” could result in a crash. This item has been fixed.
- In the “Preferences” window, the scale of the slider to set the preferences of drawing cycles versus paths is corrected.
- The drawing of dashed edges is more robust.
- Efficient closing of the application.
- The speed at which the software runs has been greatly increased. Networks are drawn about 15% faster. Calculating and drawing clusters is about 20-25% faster. The calculation of ‘paths and flows’ and ‘centralities’ has been accelerated by 40% to 50%.
- The ‘closeness centrality’ algorithm (a way to detect nodes that are able to spread information very efficiently across a network) has been added.
- The algorithm to separate overlapping vertices in the visualization of a network has been optimized.
- Memory management has been improved.
- A manually drawn graph whose layout was not managed by the software can now be saved (in the previous versions there was an error in the saved file).
- Clicking a radio button in the ‘Paths and flows’ panel when no graph was drawn in the canvas caused the software to crash. This item has been fixed.
- The radial tree layout has been added to visualize a network. A network can now be visualized using a graph, a traditional tree or a radial tree layout.
- The traditional tree layout has been optimized: vertex size and branch distribution.
- The layout algorithms have been adjusted to obtain optimal use of the canvas space. This results in a more open network structure. This is especially relevant for larger networks.
- The undo / redo action now works correctly when drawing a network with different layouts consecutively (graph, traditional tree, radial tree).
- Random graphs can be created (menu ‘Extras’; submenu ‘Create a random graph’)
- When a graph is converted from directed to undirected, the option to save the directed graph before converting it to an undirected graph is active.
- The help window that appears when a control is right-clicked is now always in the foreground (in the previous version, the help window could be partially hidden by a window).
- If graph data is imported (menu ‘File’; submenu ‘Import graph data from the clipboard’) and the weight of an edge is zero, the data will be processed and will not cause a crash.
- Both the s-t minimum cut and the global minimum cut of a graph can be calculated. If the graph consists of multiple subgraphs, the global minimum cut for each subgraph is calculated.
- The layout and help functions (right click on the controls) of the Palette window have been made more consistent.
- The calculation of the shortest path, the longest path, and the minimum spanning tree is more efficient.
- After importing graph data from the clipboard, the resulting graph is always drawn automatically (sometimes an additional click on the “Draw graph” button was needed).
- After calculating the shortest or longest path, direct drawing in the canvas is always possible (in previous versions this could lead to a crash).
The last version can be downloaded at the menu item Software
To explore the features of DiscretePath consult the user guide (User guide)
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