Interfacing Netlogo with external agents - api

Can someone guide me as googling does not send me to the right places.
I want to adapt netlogo to include players real or simulated with other technologies. I need to interface the netlogo core (running an established game) and have the moves and choices determined by the external entities, which may be human or automania.
In searching for the API to allow this, I can find is the controlling API which is seems to be for running NetLogo muitiple runs of a model and not what I want.
And please before you close this again suggest how I can make this more focused as the problem is finding the starting point....
Can anyone assist.
Regards
Robert

There are two main ways to interface between NetLogo and the "outside world":
The extensions API.
The controlling API.
Which one to use depends on what you're trying to achieve.
You say that you:
need to interface the netlogo core (running an established game) and have the moves and choices determined by the external entities, which may be human or automania.
That, to me, sounds very much like a job for the extensions API, which is what has been suggested to you on the netlogo-devel group. Extensions allow to add new "primitives" to NetLogo, and those primitives can be written in any language that runs on the JVM (Java, Scala, Clojure, etc.)
So if you have a game written in NetLogo and a bot written in some other language that the JVM can interface with (possibly by using the JNI), you could write a new NetLogo extension command that calls out to the bot (e.g., something like bot:play game-state). A game written in NetLogo could then use that command to let the bot play its turn.
If that is indeed what you want to do, then Jeremy has already given you a good starting point in his netlogo-devel answer, and there is not much we can add to this until you have more specific questions.
You also said, however, that you looked at using the controlling API, so maybe what you had in mind is to have a game written in some other language, and use a NetLogo model to generate the behaviour of a particular player in that game. The controlling API allows you to do that. (It's not just for running a model multiple times!) If you look at the examples in the controlling guide, you'll see that you can use the API to send commands to a NetLogo model and to report the results back to your external program. The only constraint is that this external program needs to be able to talk to the JVM.
If you don't think this answers you question, please try to give us a concrete example of a precise thing that you want to do but do not think can be achieve in one of these two ways. We might be able to help you better than.

Related

A Conceptual Understanding of APIs

I have been learning coding for about a month now. I have some good experience with Python, and additionally I have completed this web development course on Udacity.
Now, I have a good foundation for programming, but one thing that confused me a lot is how to interact with various websites and APIs. The course I did briefly touched on this in terms of XML and JSON files and how some webpages offer their pages in these formats for easier reading by other machines.
But there are still a bunch of tasks which I have no idea how to approach whatsoever, but want to eventually do. I have constructed some hypothetical examples for the purpose of this question. I will post my current rough understanding of how I would do them below each one, and would appreciate feedback (on the API interaction, not on the front-end or on any back-end algorithms/AI/parsing):
Creating a phone application (disregarding the front-end part) which can then communicate with and perform rudimentary tasks on my computer.
I have no idea how to do this, and my guess would be that I would have to look into some external application/API meant for this process and implement this on both-ends of the system.
Being able to write a bot which goes on to a game website and controls the object via script. (e.g going onto a pacman game website written in flash and automatically controlling the character to avoid the ghosts)
I don't even know if this is possible, or how browser flash games interact handle the user-server interaction. Would I have to post some data via HTTP manually in the same way that playing in the keyboard would do? Or is everything done client side, in which case how would I fake user input? How would I get information on the ghost's position to work the AI?
Creating a mobile app for my school by allowing users to put their username and password into the app and then having the app automatically log in to the school and fetch certain data (e.g timetable) and return back in a readable form.
I'm guessing that I would take the input from the user on my mobile-app, and then navigate to the school's login page and POST this data in the relevant forms to log in. And then that I would (somehow, not sure), navigate to the timetable URL through my code while still managing to stay logged in, and then parse the html there?
I would appreciate some detail on how these kind of things are done, preferably with reference to these examples, so that I can get a better conceptual understanding.
Thanks!
Note: I have asked all those various questions mostly rhetorically, just so that those reading can get a better understanding of what my current programming level and understanding of APIs is at. I do not expect nor require specific answers for each and every question (so I hope this doesn't get flagged as being too vague or requiring too much detail!), I just would appreciate some responses telling me roughly how each of these APIs work approximately and how I would even start at looking at how to do these things.
You asked too many questions and honestly speaking I am not able to read and grasp entire text posted by you.
So, I am focusing only the title of your question:
"A conceptual understanding of API"
API (Application Programming Interface) means a set of functions which you can directly use by simply passing parameters to them.
Actually, in application development there are many common functions which every application programmer have to use. So, instead of coding them every time by every programmer, they are already coded in functions which you can use simply by passing parameters to them (if they need any external parameter).
Example:
I am offering you a maths API, set of functions {add, sub, mul, div}. You can pass two numbers to any of these four functions and get desired result instead of coding every time for ever operation like add, sub, mul and div.
Hope it helps...

digital audio workstation with API

Do you know any digital audio workstation that has API? I would like to create application that can generate music based on such programs possibility. This is purely for my own entertainment, I don't mean to make any kind of commercial moves...
There are a couple of different DAW's you can look at that allow you to interface with a variety of languages. The main ones that spring to mind are Reaper and Ableton. As far as I know, Ableton uses python internally and some clever people have found ways of taking advantage of that here;
https://code.google.com/p/liveapi/
The other one is Reaper, which allows you to script its internal features using Python using something called ReaScript;
http://www.reaper.fm/sdk/reascript/reascript.php
Hope that helps.

Game Design: Is a plug-in the best solution for this Problem? (Cocoa, Objective-C)

I've started helping with an open source game (based on Cocoa, Obejctive-C, Xcode). The existing game engine is already setup to allow the character to run around the world, encounter an enemy, and when combat is begun, a characterObject is called with the enemy unit object that is to be attacked. This characterObject has a default method of attacking the enemy.
I wanted to improve on this design by extending the program to allow others to develop a combatUnit plugin that would handle the combat actions in their own programmed way. This could open up the community to develop different styles of combat and come up with their own unique play style.
As I began to look into Plug-Ins and examples on how to build, most of the examples kept the plug-in relatively isolated from the internals of the rest of the program. And any data the plugin required would be passed into the routine(s) themselves.
However, in this case, a combat unit developer might want to have access to numerous external objects in the existing game: a developer might want to also know of any nearby enemy units to avoid any potential adds in a fight and would have to access several of the existing environment objects to get that data, the character might be in a group and the developer might want access to the group info and each players data to determine if they should heal, etc... Not knowing what a developer has in mind, it would be unfeasible for me to attempt to predict and pass in all potential info for them to use.
So, my question is:
Is this a good application for a Plug-In? If so, when developing the plug-in how do I open up the other objects for the plug-in developer to code against?
Is there another approach to solve this problem? Something else than a "Plug-in" that would be more appropriate for the code to have access to the game's objects?
Thanks for you help!
That’s a good case for making plug-ins. As an alternative you could compile the new objects directly into the game or use a scripting language interpreter. But with those you’d have to solve the same problems of how to give access to the internals of the game to the new combat unit.
The cleanest way to do this would be to define an interface to the game (either as a protocol or a base class) and pass that to the plug-in. Using this object the plug-in can then query anything it needs.

How do I hook into a game and write a script to manipulate it?

I know this is a pretty open question but I was wondering how people go about writing scripts that will "play" a game, or manipulate it in some way. I had been thinking that I'd try to get a working AI to play a game for fun, but don't even really know where to start. Are there any good resources to learn this? What are good languages to use? Once I have the language, how do I get my script hooked into the game? I was thinking of just trying simple flash games, if that helps.
Thanks a bunch!
Are you looking to "play" an existing game, or write some sort of a game that can then be scripted?
If the former, you find that game's API and start writing code in the appropriate language. E.g. Unreal-powered games use UnrealScript and ship with the tools so you can embed new functionality. You're pretty much dependent on the game creators leaving an "in" such as this...
...unless you want to get totally nutty and hack the executable itself to execute your own code somehow. For information on how to do this, search for information on game "trainers". I'm not sure what a great set of search terms would be, but I know a lot of games do have trainers released, so type in "trainer <my_favorite_game>" and see what you get?
You can do this quite simply in Java 6.
expose your objects/functions in your Java app into the scripting environment
For example you can expose your character or the game world into the scripting environment and allow the script to control it.
invoke script functions/methods from Java environment
Allow the script to customize behaviours, add new actions, etc. Another use of this is to override the default build in game rules and load your own house rules. Another use is as a macro facility. Typically this would be part of the main game loop
use the script as a data/level file
For example, in a game likes SpaceHulk where it is mission based, you can use a script to define a game specific DSL, and us this DSL to define new missions. When the game starts up, it evaluates the data file and create a model of the game.
To integrate a scripting engine into Java, simply do this
ScriptEngineManager mgr = new ScriptEngineManager();
ScriptEngine jsEngine = mgr.getEngineByExtension("js");
jsEngine.eval("print('Hello world!');
To expose an object into the script environment
jsEngine.put("avatar", avatarObject);
//An avatar object is now available in myscript.js
jsEngine.eval(new FileReader("myscript.js");
To invoke a function in the script
jsEngine.eval("function hello(name) ... ");
Invocable inv = (Invocable)jsEngine;
inv.invokeFunction("hello", "Fred");
One of the problem with scripting is that, the script has access to your entire application. You can restrict what the script can 'see' by setting a classloader when you create the ScriptEngineManager instance.
Java 6 comes with a bundled JavaScript engine. However I prefer Groovy and loading Groovy basically mean changing 'js' in getEngineByExtension() to 'groovy'.
I know that a lot of people say that Java is not fast for games, but if you are writing turn based games or social games like Farmville then I think it is more than adequate.
For C/C++ based games, I think the preferred script engine is Lua. I've not used it so I cannot comment on it.
The best way to do that is to use the API provided by the game, if there is one. The Civilization games, for example, come with a very complete modding engine that allows you to script whatever you want. The same can be said for Age of Empires and a variety of other games.
Simple flash games, though? That'll be tough. Those don't generally provide any supported way to script, so you'll be left with simulating input. It'll be tough.
The easy way is to control mouse and keyboard functions with autoit. You can also read out information from your screen, but it is a bit limited It is good to just check if things changed or check whats on a certain area of the screen if you know there are a limited amount of possibilities. Not so easy to read and interpret text. Autoit is excelent to automate games like farmvile. I have also made blackjack bots for online casinos. And use it for small but mundane and repeating (manufacturing) tasks in RPGs. Dont expect to build an AI for an RTS or FPS though.
Autoit is easy to find with google. A fast and small download. Excelent documentation and you can learn it in days.
The hard way is what people wrote about above here i guess. Interacting with the game data. Searching information on that is what brought me here. I see its with C++ or Java. While the languages are all similar and you can use them all after learning 1, these come with complicated software environments that take lots of time to learn. The possibilities and chances to make something really reliable are much much greater though.

Language-Portable Example Programs

At the moment I am learning Objective-C 2. I'm aware that it's used heavily by Mac developers, but I'm more interested in learning the language at this point in time than the frameworks for developing on Mac OS X/iPhone (except for Foundation). In order to do this I want to write a few intermediate* console applications, but I'm stuck for ideas.
Most examples are something along the lines of "Write a Fraction class that has getters/setters and a print function", which isn't very challenging coming from a C++ background. I'd like some generic examples of programs, but I don't want them to include any Objective-C implementation details. I want to figure out the program structure/write my own interfaces and learn the language from there.
In summary: I am curious as to what example programs Objective-C programmers would recommend for exploring the language.
An example of an "intermediate" application would be something along the lines of "Write a program that takes a URL from the command line and returns the number of occurrences of a certain word in data returned:
example -url www.google.com -word search
"Project Euler" is a standard response for this kind of thing, but I get the feeling that you're less interested in being told to implement algorithmic stuff (since that knowledge is easier to port between languages) and more interested in miniprojects that will familiarize you with core libraries. Is this fair?
If so, IMO, you ought to know the basics of how to do the following with the standard libraries of language you hope to use for serious work:
Standard IO
Network IO
Disk IO and navigating the filesystem
Regexp utilities
Structured data (XML libraries and CSV libraries if they exist)
Programming problems I would recommend for those:
It sounds like you've already done this.
A very simple proxy - something like what you described in your post, but that listens on a port for a message containing a URL rather than taking it on the command line, and likewise returns the results to whatever contacted it over the network rather than outputting to stdio. [Obviously you need to have the machine behind an appropriate firewall for this!]
Something which takes a directory path and recursively tallies the number of lines its children contain. (So, get the directory's listing, open each child file and count the number of line breaks. Then open each of its child directories, get their listings, ...) Record any errors encountered (e.g., no read privileges) in a reasonable way. Write out the final results to file in the directory supplied.
Usually if I tool around in a language enough, I'll run across some problem which I just naturally find myself using regexps for. I'll assume the same is true for you and punt this element for now.
Fetch StackOverflow.com, and [by putting it into a DOM model and navigating that] determine whether this question is still on the front page.
I got the most out of Objective-C by exploring it with a testing framework. I have written a short blog post about it. You should also wrap your head around the memory management conventions employed by Objective-C, reference counting takes a little time to get used to but works very well if responsibilities are clearly segregated (I have written about that on my blog too).
By getting my hands dirty on a testing framework (GHUnit for that matter), I was able to learn far more about the language than I could have in a "traditional" way. Of course you'll need a little pet project, otherwise this approach doesn't make sense.
I don't think your example is a very good idea as it requires you to mess with http connections, resources etc. which is a little framework specific after all. Parsing a text file would be a little easier in this regard. Using a unit testing framework has the following advantages for you:
learn about platform specific build systems and deployment details
forced to develop components in a loosely coupled fashion from the ground up
thereby exploring unique mechanisms of the language, that might require new or make known patterns redundant (e.g. categories make dependency injection obsolete etc.)
fast compile-test cycle, less time spent in front of the debugger
combined with source control: painless experiments
You should also look into the testing framework implementation, as testing frameworks always require to work with metadata to some extend. Testing frameworks are often used together with isolation frameworks. They basically create objects at runtime that comply to certain interfaces and act as stand-ins for concrete objects. Looking at their implementation will teach you about the runtime manipulations that can be done in Objective-C (keyword: Method-Swizzling)