I am certain that the inheritance symbol used in ERD diagram is the triangular symbol.
However, I am uncertain of the symbol used in UML diagram that is used to symbolize inheritance.
I have searched on the Internet and I have seen the symbol of a circle icon with an underline below it.
May I know which is the correct inheritance symbol used in UML diagram?
Thank you
Both Generalization as Realization have a triangle endpoint.
The difference is the dotted line for Realization (implementation) vs the solid line for Generalization (inheritance).
In the world of ER modeling, what you are describing is called generalization/specialization. Another phrase is "is-a relationships. For a related wikipedia article, click here and scroll down to UML.
It is triangle for generalization (inheritance), and can be circle (lollipop notation) for realization (implementation of an interface).
Related
How to draw ER diagram for this.
Players plays game.game is controlled by refree. Organizer organizes game and pay to refree. Refree is appointed by federation. Assume your own sets on attributes.
I am trying to see what the er diagram is for this question
While using power designer, I have ended up with a mess of lines for references from one table to the other. While these lines are orthogonal, they create a mess, hiding behind tables, etc.
Is there a way to make them snap to grid lines so they are more readable?
Which version are you using? With version 15.0+, there is an auto-layout tool, under Symbols > Auto-Layout, which could help to avoid the routing by reordering the tables.
I think some efforts have been made in 16.0+, around links crossings.
you can use graphical synonms..use Ctrl + C to copy the entity. and then Ctrl + K..
It will create replica to main entity to which other entities are linking. You can put this entity with other entities on other page ( if you are using page layout) and it will avoid crossing of lines and your diagram will look beautiful.
The auto-layout tool certainly helps with lines that are hidden, but it isn't perfect either. It tends to hide lines when diagrams get to big. I think the optimal way is having multiple diagrams centered around your different subjects which can already reduce the problem.
Aside from that, if you right click on a relationship, there is a Disposition option which gives you a certain flexibility to re-arrange lines, like re-ordering attach points.
Tools -> Display Preferences -> ckick on your line type -> Format -> Modify -> change line corners to not orthogonal and draw them as you like)
Im trying to triangulate a polygon for use in a 3d model. When i try using the ear method on a polygon with points as dotted below, i get triangles where the red lines are. Since there are no other points inside these triangles this is probably correct. But i want it to triangulate the area inside the black lines only. Anyone know of any algorithms that will do this?
There are many algorithms to triangulate a polygon that do not need partitioning into monotone polygons first. One is described in my textbook Computational Geometry in C, which has code associated with it that can be freely downloaded from that link (in C or in Java).
You must first have the points in order corresponding to a boundary traversal. My code assumes counterclockwise, but of course that is easy to change. See also the Wikipedia article. Perhaps that is your problem, that you don't have the boundary points consistently organized?
The usual approach would be to split your simple polygon into monotone polygon using trapezoid decomposition and then triangulate the monotone polygons.
The first part can be achieved with a sweep line algorithm. And speed-ups are possible with the right data-structure (e.g. doubly connected edge list). The best description of this, that I know, can be found in Computational Geometry. This and this also seem helpful.
Wikipedia suggest that you break the polygon up into monotone polygons. You check that the polygon is not concave by simply checking for all angles being less than 180 degrees - any corners which has a angle of over 180 is concave, and you need to break it at that corner.
If you can use C++, you can use CGAL and in particular the example given here that can triangulate a set of non-intersected polygons. This example works only if you already know the black segments.
You need to use the EarClipping algorithm, not the Delaunay. See the following white paper: http://www.geometrictools.com/Documentation/TriangulationByEarClipping.pdf
I'm trying to research existing works in the area of recognizing complex graphical gestures, but struggling to find good search terms or clear documents in the field.
For example, I might want to recognize an arbitrary shape drawn by a mouse as a path, or a path with an arrow head, or an enclosed region, or some combination of various shapes. One of the problems I'm having is that the shapes are not necessarily going to take a consistent symbolic form, so I'm looking for alternate ways to represent the data.
This article has been helpful so far, but does not discuss any concrete algorithms.
http://www.springerlink.com/content/l4235612gv479262/
Anyway, I'm not necessarily looking for solutions here (though I'd be interested if there were some), but if people can help direct me towards some pertinent papers or the right kinds of search terms, I would appreciate it!
If you take the sequence in which the gesture is made/drawn into account then you might want to make use of sequence alignment techniques. Asking Google gives quite a few matches which you might want to explore.
I want to design an associate silverlight diagraming surface where you can type in boxes, and then drag these boxes around and link them up to other boxes using lines, arrows. My first problem is what is the first step to take to go about this approach? I am looking for something like a mindmap or visio diagram.
Thanks,
Eric
Hi give a try to SilverDiagram (it contains a free and commercial license):
Demo
http://www.silverdiagram.net/Scripts/SD.Client.MainTestPage.aspx
Site
http://www.silverdiagram.net/Projects/Silverdiagram.aspx
Samples
http://silverdiagram.codeplex.com/
I found my own answer to this question for anyone who is interested: http://forums.silverlight.net/forums/p/23895/89599.aspx