mvellandi

mvellandi

Exploring Graphs with Elixir: Missing directories (p 100, 105)

Exploring Graphs with Elixir by @tonyhammond

p.100 – Ch 3 > Storing Graphs in the Graph Store > Listing
shows

“iex>​​ ​​list_graphs​
​ 	[..., "default.dot", "IMAGES", ...]”

but (to my recollection) we have not defined this directory yet, either manually or automatically through the shell command in:
p.68 – Ch 2 > Building a Graph Store > Creating a Storage area

I see a reference to this “images” directory later, as a module attribute in NativeGraph.Format
So I manually created it.

Then in
p.105 – Ch 3 > Visualizing Graphs > Rendering with Graph Viz
while creating the water molecule graph, we’re given:

“iex>​​ ​​with​​ ​​{:ok,​​ ​​dot}​​ ​​=​​ ​​Graph.to_dot(g)​​ ​​do​
​ 	​...>​​ ​​write_graph(dot,​​ ​​"dot/h2o.dot"​​)​
​ 	​...>​​ ​​end”

When trying this, I get a File error since the “dot” directory is unavailable. Not sure what I’m missing here, or if the directory is supposed to be automatically created?
I manually created a “dot” directory to make the code work as shown and tested in later pages.

Marked As Solved

tonyhammond

tonyhammond

Author of Exploring Graphs with Elixir

Yes, this was not very clear. These directories are to be added manually.

I added this text on p. 29 in Chapter 2, Building a Graph Store, section Listing:

“And we’ll also want to be able to access graphs and queries within any directories that we may add manually to our store.”

And on p. 47 in Chapter 3. Managing Graphs Natively with Elixir:

“In this case we have manually added an images/ directory.”

And on p. 49:
“And for better graph management note that we’ve manually added the dot/ and images/ directories in our graph store:”

Also I hadn’t been consistent in writing dot files to the dot/ directory. Fixed that too.

Where Next?

Popular Pragmatic Bookshelf topics Top

jon
Some minor things in the paper edition that says “3 2020” on the title page verso, not mentioned in the book’s errata online: p. 186 But...
New
belgoros
Following the steps described in Chapter 6 of the book, I’m stuck with running the migration as described on page 84: bundle exec sequel...
New
joepstender
The generated iex result below should list products instead of product for the metadata. (page 67) iex> product = %Product{} %Pento....
New
swlaschin
The book has the same “Problem space/Solution space” diagram on page 18 as is on page 17. The correct Problem/Solution space diagrams ar...
New
brian-m-ops
#book-python-testing-with-pytest-second-edition Hi. Thanks for writing the book. I am just learning so this might just of been an issue ...
New
Charles
In general, the book isn’t yet updated for Phoenix version 1.6. On page 18 of the book, the authors indicate that an auto generated of ro...
New
brunogirin
When running tox for the first time, I got the following error: ERROR: InterpreterNotFound: python3.10 I realised that I was running ...
New
oaklandgit
Hi, I completed chapter 6 but am getting the following error when running: thread 'main' panicked at 'Failed to load texture: IoError(O...
New
jwandekoken
Book: Programming Phoenix LiveView, page 142 (157/378), file lib/pento_web/live/product_live/form_component.ex, in the function below: d...
New
dachristenson
I’ve got to the end of Ch. 11, and the app runs, with all tabs displaying what they should – at first. After switching around between St...
New

Other popular topics Top

PragmaticBookshelf
Learn from the award-winning programming series that inspired the Elixir language, and go on a step-by-step journey through the most impo...
New
Exadra37
Please tell us what is your preferred monitor setup for programming(not gaming) and why you have chosen it. Does your monitor have eye p...
New
DevotionGeo
I know that -t flag is used along with -i flag for getting an interactive shell. But I cannot digest what the man page for docker run com...
New
Rainer
My first contact with Erlang was about 2 years ago when I used RabbitMQ, which is written in Erlang, for my job. This made me curious and...
New
AstonJ
There’s a whole world of custom keycaps out there that I didn’t know existed! Check out all of our Keycaps threads here: https://forum....
New
AstonJ
I have seen the keycaps I want - they are due for a group-buy this week but won’t be delivered until October next year!!! :rofl: The Ser...
New
PragmaticBookshelf
Learn different ways of writing concurrent code in Elixir and increase your application's performance, without sacrificing scalability or...
New
AstonJ
Biggest jackpot ever apparently! :upside_down_face: I don’t (usually) gamble/play the lottery, but working on a program to predict the...
New
PragmaticBookshelf
Author Spotlight Mike Riley @mriley This month, we turn the spotlight on Mike Riley, author of Portable Python Projects. Mike’s book ...
New
hilfordjames
There appears to have been an update that has changed the terminology for what has previously been known as the Taskbar Overflow - this h...
New

Sub Categories: