I want to implement Prestack Kirchhoff Time Migration in java and later convert the code into Map-Reduce mechanism. Can someone give me some links for relative study or help me about how to implement this?
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I'm a beginner.
I'm trying to research how the behavior of a vehicle changes if you set an estimated time of arrival for each vehicle using sumo and veins, and drive according to that time.
Of course, I think it would be difficult to implement this without traffic conditions and a smart navigation system, but I'm thinking of giving it a try.
Now, when I implement it, I want to add an attribute to that is not provided in sumo.
I checked the sumo file and it seems to be set in the C++ file, but I couldn't find where I should add it.
Also, I think I need to make some changes to the veins to process the data after adding it in sumo, where can I look to learn more?
Here are the tools I'm using
sumo (1.8.0) veins (5.1) omnet++ (5.6.2)
I am sorry, but I would appreciate it if someone could push this for me.
If you want to add arbitrary attributes to vehicles, this can be done using what SUMO calls "Generic Parameters". See https://github.com/eclipse/sumo/blob/v1_8_0/docs/web/docs/Simulation/GenericParameters.md for a quick explanation, see https://github.com/sommer/veins/blob/veins-5.1/src/veins/modules/mobility/traci/TraCICommandInterface.h#L167 for a way to access them from OMNeT++.
I am at the first time creating a huge program in C++ for my company and I want to create a good pattern to connect into my MySql db. I have these problems:
-I can't decide which pattern should be used, DAO,
Repository, UnitOfWork, Factory..
-I can't find a good examples of data access pattern in C++, I know it should be independently of language but I couldn't find even a robust
DAO pattern example with a good exception handling etc... Commonly are
only two classes (obj1->obj2) on very small environment.
If someone knows good sources or any tips I will be very glad =D
Thanks in advance.
My advice is search for c++ ORM(Object Relational Mapping) there are plenty ORM or DAL solutions on java like Hibernate, Datanucleus, SQLite ..
We are using Datanucleus and we are happy with it but i dont think datanucleus have a support for c++. Imho creating DAL form scratch is unnecessary.
I had the same problem years ago. The list of ORM for C++ in Wikipedia is very short and the most promising product is under GPL or you have to buy it.
We decide to develop our own ORM. There are several enterprise design patterns for it. We choose the way obd uses: Your tables was described from simple classes. The persistence and access of objects are handled from an database-manager. The most costliest todo is to write your own query-interface (if you don't wand to type clear sql in your code).
I feel helpless especially without proper documentation for WSDL2C codegen tool. Here is the question with little background:
I was able to download the WSO2-WSF-C-SRC (C source) and able to compile and get the SOAP server running. Also created a wsdl file and generated server skeleton code using WSDL2C codegen tool. The codegen code is way bigger than the code that appears in the Samples provided in the download. Unfortunately, there isn't much literature for the code generated by the WSDL2C tool. Can someone help as to how the start my business logic coding? How to set some default values to all the output parameters? I was able to figure out the location to start. I wish there is a sample code somewhere with the business logic code as well. Can someone help?
Thanks in advance.
Well, I cracked the code. Obviously, one has to go through the code to understand the basic structure, which I did, finally.
Best Wishes.
We are planning to use django-haystack with Solr4.0 (with near real time search) for our web app, and I was wondering if anyone could advice on the limits of using haystack (when compared to using solr directly). i.e is there a performance hit/overhead of using django-haystack? We have around 3 million+ documents which would need indexing + an additional (estimated) 100k added everyday.
Ideally, I'd think we need a simple API over Solr4 - but I am finding it hard to find anything specific to python which is still actively maintained (except django-haystack ofcourse). I'd appreciate any guidance on this.
It seems like your question could be rephrased "How has Haystack burned you?" Haystack is nice for some things, but has also caused me some headaches on the job. Here are some things I've had to code around.
You mentioned indexing. Haystack has management commands for rebuilding the index. We'll use these for nuke and pave rebuilding during testing, but for reindexing our production content we kind of hit the wall. The command would take forever, you wouldn't know where it was in terms of progress, and if it failed you were screwed and had to start all over again. We reached a point where we had too much content and it would fail reliably enough. We switched to making batches of content and reindexing these in celery tasks. We made a management command to do the batching and kick off all those tasks. This has been a little more robust in the face of partial failures and, even better, it actually finishes.The underlying task will use haystack calls to convert a database object to a solr document -- this ORMiness is nice and hasn't burned me yet. We edit our solr schema by hand, though.
The query API is okay for simple stuff. If you are doing more convoluted solr queries, you can find yourself just feeding in raw queries. This can lead to spaghetti code. We eventually pushed that raw spaghetti into request handlers in the solrconfig file instead. We still use haystack to turn on highlighting or to choose a specific request handler, but again, I'm happier when we keep it simple and we did hack on a method to add arbitrary parameters as needed.
There are other assumptions about how you want to use solr that seem to get baked in to the code. Haystack is the only open source project where I actually have some familiarity with the code. I'm not sure if that's a good thing, since it hasn't always been by choice. We have plenty of layer cake code that extends a haystack class and overrides it to do the right thing. This isn't terrible, but when you have to also copy and paste haystack code into those overridden methods then it starts being more terrible.
So... it's not perfect, but parts are handy. If you are on the fence about writing your own API anyway, using haystack might save you some trouble, especially when you want to take all your solr results and pass them back into django templates or whatever. It sounds like with the steady influx of documents, you will want to write some batch indexing jobs anyway. Start with that, prepare to be burnt a little and look at the source when that happens, it's actually pretty readable.
I'm trying to code a small program for my friend's company. They build metal cabinets and every cabinet is made out of several parts. So when a customer tells them they need a new cabinet, they tell them the single part numbers. My friend needs now a little tool/database where he can look after those part numbers and if there is an entry, he can download the corresponding blueprint (saved as PDF). Of course the program needs also a function to create a new entry and uploading a PDF file with this entry.
The program needs only to be installed local on one windows machine.
Now I need to know if there is maybe a special way to solve this. It would be helpful if someone could give me some keywords, so I can google it and figure out how to begin :)
I have basic skills in C++ and Java and willing to learn new stuff :)
thanks!
Have used sqlite for database applications and found it to have a lot of functionality and speed. It lacks all the advanced database admin stuff but for single user/embedded databases its ideal. I use it over MySQL because of a significant performance improvement.
It has a Java interface via java.sql.Connection.
I think this is a good opportunity to try something else than C++/Java. In your case I would go for Ruby on Rails and for example the PaperClip extension (http://thoughtbot.com/community/) (haven't used PaperClip myself, though). Ruby on Rails is kind of made for this type of problem.