Re: Drawing a circular flow

[Marshall Feldman <marsh uri edu>]

Date: Fri, 19 Apr 2013 21:29:37 -0400 From: Alejandro Imass <aimass yabarana com> To: marsh uri edu, discussions about usage and development of dia <dia-list gnome org> Subject: Re: Drawing a circular flow Message-ID: <CAHieY7Q0m+q1dHARy8wJRpXgb+qDPYR=uyhTuE5p3GyvXCZAjA mail gmail com> Content-Type: text/plain; charset=ISO-8859-1 On Tue, Apr 16, 2013 at 9:17 AM, Marshall Feldman <marsh uri edu> wrote:

Hello,

I'm new to Dia and have found it very useful. But I'm having one problem. I
want to draw an arc that starts and ends at the same node. I tried using the

You can do it if you connect it to something else. Example take a box
and you can illustrate a loop connecting an arc for example from the
right side of the rectangle to the top.

Thanks. I managed to draw an arc from the top of a rectangle to its side. So, by "something else" you don't just mean another object. Different sides of a polygon count as "somethings else." Is this behavior documented anywhere? Exactly what counts as (i.e., what is the technical definition of) "something else."

curved line connector and can almost make it into a circle, but when the end
of the line gets close to the original box, it seems to collapse on itself,
so instead of a circular flow it just looks garbled.

Weird. It works for me. Please specify your version and OS. Also
specify if you are using the arc primitive or an arc provided by a
symbol sheet.

I'm using Dia 0.97.2 on a Mac running OS X 10.7.5.

I don't know what you mean by "arc primitive" or "symbol sheet." The Dia Manual refers to a "Toolbox." I'm using the Toolbox items for flowcharts. In particular, mainly rectangles and parallelograms. To connect the shapes, I'm using straight lines and curved arcs.

Funny, when I made a simple diagram consisting of just a rectangle and a circular arc, everything worked fine for me. First I drew the arc from the top of the rectangle to its right side. Then I moved the arc by moving the tip (arrowhead) of the arc to the top side of the rectangle. Finally, I made the arc more circular by moving its origin (the original end of the arc, i.e. the one without an arrowhead) to the top line of the rectangle.

I ran into trouble when I had a more complex, busy diagram and just tried to add a circular arc to a rectangle.

In case you're wondering why I want this, think of a bank ledger for a
mortgage. Every month, the bank adds interest due to the balance of the
mortgage. If there's mortgage payment (a separate flow transaction), the
balance is reduced. But the original ledger entry starts and ends with the
bank.

I understand you want an arc to illustrate something looping into
itself. is this a flowchart that you are trying to do, is it some
specific notation? Can you provide an example on the Web on what you
are trying to accomplish?

No, it's not exactly a flowchart. If you want to see an example, look at Figure 9.3 on p. 175 of this paper. This is a monetary flow diagram designed to show money flows in an economy. To visualize an example, think of an economy consisting of two sectors, one producing consumer goods and one producing capital goods. The consumer goods sector buys capital goods from the capital goods sector, so money flows from the former to the latter. On the other hand, the capital goods sector buys capital goods from itself. So a portion of the money it receives circulates within the sector, or in other words, goes from the capital goods sector to itself. Besides showing flows between economic entities, I want to show flows within individual entities, such as those within the capital goods sector.