Recent content by davidpen

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  1. davidpen

    A New entry in my Gentle Model Railroads blog

    There is a new entry in my Gentle Model Railroads blog - Wiring is in place.
  2. davidpen

    A New entry in my Gentle Model Railroads blog

    There is a new entry in my Gentle Model Railroads blog - 1st run of Amtrak 737
  3. davidpen

    A New entry in my Gentle Model Railroads blog

    The link works for me but try this http://www.gmrblog.co.uk.
  4. davidpen

    A New entry in my Gentle Model Railroads blog

    There is a new entry in my Gentle Model Railroad blog - Putting in the wiring busses. Check it out.
  5. davidpen

    A New entry in my Gentle Model Railroads blog

    There is a new update on my Gentle Model Railroad blog. Here I describe my process in getting the boards made for the new HO layout. Check out my first attempt at stop framing!
  6. davidpen

    I am back with my blog but HO this time

    Here is the current iteration of the HO Switching layout that I am going to build.
  7. davidpen

    I am back with my blog but HO this time

    Hi everyone. Not been around for a few years since I lost my hobby room when my mother-in-law came to stay (she is 97!). Having struggled to get a few layouts going, I have finally settled on a 7' long HO switching layout. If you would like to see all of my history - it goes back to 2009 -...
  8. davidpen

    Freight Car Routing - My university project moves on

    "Empty box cars come from the general pool so can be sourced from either end of the railroad". This includes reefers. "The problem I see with this is that if you have the engine proposing a higher demand than there are cars available, the owner will never know he is short of cars, and...
  9. davidpen

    Freight Car Routing - My university project moves on

    This is how it works. I was just explaining to the previous poster how my software looked like his pseudo code. My blog at https://tm470routingproject.blog explains: "the DE has to track through every location that could source or require a car and assess any need. Once this analysis is done...
  10. davidpen

    Freight Car Routing - My university project moves on

    Industry X -> Car Type A When Industry X Needs Random(number) Cars -> Create Train When Create Train ADD Car type (Industry X.CarType) I write in Smalltalk and in pseudo code that comes out as: Car Type A sendTo: IndustryX; [IndustryX needsRandomCars(aNumber)] ifTrue:[ CreateTrain...
  11. davidpen

    Freight Car Routing - My university project moves on

    I think that you are thinking about traditional databases. The only thing that matters in this scenario is "this train". The system builds the train for you. You use the information; tell the system that you have moved all of the items; the system updates for the new locations and then that...
  12. davidpen

    Freight Car Routing - My university project moves on

    Only if you are using it as though it was a SQL db (which would be pointless). KV databases are used for fast access by keys - not by searching. There are objects in buckets accessed by keys. You use it by dumping and reading complete records ( not an expression that I like - I prefer...
  13. davidpen

    Freight Car Routing - My university project moves on

    Not using a SQL database. On a Key/Value database, there isn't any normalising. You have multiple copies of data under different keys. Using an example of my model shop web data base: key -> Value SaleID -> sale record. Client Name -> sale record list Client ID -> sale record list and so on...
  14. davidpen

    Freight Car Routing - My university project moves on

    I am busy working away on the project. Although it is, supposedly, a software project, the University sees it as a project report. I am expecting to have a working prototype to accord to the the original design once the course ends but the University deliverable is a 10,000 word report. To help...
  15. davidpen

    Avoiding my wife's complaints

    I have been model railroading since the mid-50s but almost never had a fully working layout. Something always gets in the way. As I am now retired and building a railroad "properly" my wife demanded(!!) that I have some people:-) To stop the trouble, I not only have people but I also have cows!
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