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Does any know how to extract a tensorflow DNNRegressor model and evaluate manually?

I am trying to use a DNNRegressor model in a java realtime context, unfortunately this requires a garbage free implementation. It doesn't look like tensorflow-light offers a GC free implementation. The path of least resistance would be to extract the weights and re-implement the NN manually. Has anyone tried extracting the weights from a regression model and implementing the regression manually, and if so could you describe any pitfalls?
Thanks!

I am not quite sure if your conclusion
The path of least resistance would be to extract the weights and re-implement the NN manually.
is actually true. It sounds to me like you want to use the trained model in an Android mobile application. I personally do not know much about that, but I am sure there are efficient ways to do exactly that.
However, assuming you actually need to extract the weights there are multiple ways to do this.
One straight forward way to do this is to implement the exact network you want yourself with Tensorflows low level API instead of using the canned DNNRegressor class (which is deprecated btw.). That might sound unnecessarily complex, but is actually quite easy and has the upside of you being in full control.
A general way to get all trainable variables is to use Tensorflows trainable_variables method.
Or maybe this might help you.
In terms of pitfalls I don't really believe there are any. At the end of the day you are just storing a bunch of floats. You should probably make sure to use an appropriate file format like hdf5 and sufficient float precision.

Organizing many texts by swapping instances

I am planning to develop an adventure-like game.
For that I am going to have a lot of instances of classes with different texts (basicly strings).
I dont want to hardcode this many texts, so i am looking for a way to do it better.
The guy in this video ( https://www.youtube.com/watch?v=8CDePunJlck ) is using json to write text files for each class instance manually and parse them automatically into instances. That goes into the right direction.
I´m looking for more information on that, so how is this procedure called?
Its said in the video that this also works with databases?
Is there a way to design a little bit more complex stuff with things like this?
E.g. I have the case that I would like to output different texts if e.g. a local or global variable is over a treshold etc. Can I do this without hardcoding and write an own class for each of my proposed instances?
Thank you!

Your question is quite broad, and it is hard to give a definitive answer. Here are some thoughts - hope you find it helpful.
You are right that you don't want to hardcode strings. The alternative to this is storing strings as external resources, and loading them into your game at start. There are numerous ways the resource can be organized; the choice depends on your programming platform, game architecture etc. For example, you can use simple name-value approach:
AREA_1_DESCRIPTION: You stand next o a small white house.
ITEM_22_DESTRUCTION: The nasty snake disappears with a loud "Bang!"
Using JSON or XML will give you more structured storage, which can be of great help, since you can organize your texts so that it is easier to use them in the code:
<item id="375" name="Great Sword">
<short_description>A Great Sword of Darkness</short_description>
<long_description>The sword has almost black blade with some unknown runes engraved</long_description>
</item>
If your programming system can access a database, then you can do something similar and store texts in the tables; this, however, might make it more difficult to edit texts later. If you want to go this way, I would still recommend using XML or JSON to store the texts, and making the game import texts in DB on the first run.
You probably will also need some sort of simple template-handling engine to be able to re-use some strings. You can start with creating your version of Java String.format() method. Your method might take as a first argument an ID of a string in your string catalog, and use some simple placeholders for the parameters. Suppose you have the following entry in your catalog:
FIRE_GEM_ACTION: "The Fire Gem touches %% and in %% seconds it turns into ashes."
Then you can write a method that will do something like this:
int delaySeconds = 5;
String message = MyTemplateProcessor.process(FIRE_GEM_ACTION, "old map", delaySeconds);
The function will take the string from the catalog, search for the occurrences of the placeholders (%%) and replace them sequentially with the parameters, so in the message you will get: The Fire Gem touches old map and in 5 seconds it turns into ashes.
In general, I would recommend you to have a look at some systems specially designed for creation of adventure games. Inform 7 will be a good starting place: http://inform7.com/learn/

Inserting to and searching a large amount of data in Java

I am writing a program in Java which tracks data about baseball cards. I am trying to decide how to store the data persistently. I have been leaning towards storing the data in an XML file, but I am unfamiliar with XML APIs. (I have read some online tutorials and started experimenting with the classes in the javax.xml hierarchy.)
The software has to major use cases: the user will be able to add cards and search for cards.
When the user adds a card, I would like to immediately commit the data to the persistant storage. Does the standard API allow me to insert data in a random-access way (or even appending might be okay).
When the user searches for cards (for example, by a player's name), I would like to load a list from the storage without necessarily loading the whole file.
My biggest concern is that I need to store data for a large number of unique cards (in the neighborhood of thousands, possibly more). I don't want to store a list of all the cards in memory while the program is open. I haven't run any tests, but I believe that I could easily hit memory constraints.
XML might not be the best solution. However, I want to make it as simple as possible to install, so I am trying to avoid a full-blown database with JDBC or any third-party libraries.
So I guess I'm asking if I'm heading in the right direction and if so, where can I look to learn more about using XML in the way I want. If not, does anyone have suggestions about what other types of storage I could use to accomplish this task?

While I would certainly not discourage the use of XML, it does have some draw backs in your context.
"Does the standard API allow me to insert data in a random-access way"
Yes, in memory. You will have to save the entire model back to file though.
"When the user searches for cards (for example, by a player's name), I would like to load a list from the storage without necessarily loading the whole file"
Unless you're expected multiple users to be reading/writing the file, I'd probably pull the entire file/model into memory at load and keep it there until you want to save (doing periodical writes the background is still a good idea)
I don't want to store a list of all the cards in memory while the program is open. I haven't run any tests, but I believe that I could easily hit memory constraints
That would be my concern to. However, you could use a SAX parser to read the file into a custom model. This would reduce the memory overhead (as DOM parsers can be a little greedy with memory)
"However, I want to make it as simple as possible to install, so I am trying to avoid a full-blown database with JDBC"
I'd do some more research in this area. I (personally) use H2 and HSQLDB a lot for storage of large amount of data. These are small, personal database systems that don't require any additional installation (a Jar file linked to the program) or special server/services.
They make it really easy to build complex searches across the datastore that you would otherwise need to create yourself.
If you were to use XML, I would probably do one of three things
1 - If you're going to maintain the XML document in memory, I'd get familiar with XPath
(simple tutorial & Java's API) for searching.
2 - I'd create a "model" of the data using Objects to represent the various nodes, reading it in using a SAX. Writing may be a little more tricky.
3 - Use a simple SQL DB (and Object model) - it will simply the overall process (IMHO)
Additional
As if I hadn't dumped enough on you ;)
If you really want to XML (and again, I wouldn't discourage you from it), you might consider having a look a XML database style solution
Apache Xindice (apparently retired)
Or you could have a look at some other people think
Use XML as database in Java
Java: XML into a Database, whats the simplest way?
For example ;)

Which Java data object to use for multidimensional range matching?

Project Background:
I am writing a map tile overlay class for java that can use gdal2tile.py tiles. Basically I will end up with thousands of jpg files that are in a file structure like
"Zoom Level/X coordinate/Y coordinate"
The coordinates are ints but will not necessarily start at 0 or 1.
I will have to search for tiles that are within a certain range to find out which ones I need to render.
My Problem:
I tried iterating using the file structure itself but it is wicked slow (not surprising).
I tried iterating using an ArrayList of strings of the file structure and .contains() but it seems to be even slower (not too surprising).
Optimally I would like to use a data structure that would let me choose a range on multiple dimensions so that I can call something like.
Tiles.getWhere(Zoom Level,min X,max X,min Y,maxY);
I assume that some sort of Collection or TreeMap would be the right choice but I'm not experienced enough with Java to know for sure and I'd prefer not to have to benchmark a lot of different approaches.
I could use SQLite to do it but that seems like overkill.
My Question:
What is the most efficient way to check for the existence of datasets given multiple dimensional constraints?

May be you are looking for a map with multiple keys.
Commons-collections provides a map with multiple lookup keys:
http://commons.apache.org/collections/apidocs/org/apache/commons/collections/map/MultiKeyMap.html
a map guarantees a O(1) insertion and O(1) selection timings.

Thinking of your problem I could find out three directions to which you could aim your search next (this is not a hand-by-hand guide but rather a out-of-the-box brain opener for a stucked situation you have faced):
1) Usage of Java built in structures. Yes, indeed, a list is the worst case of a searching method. A Map, as the name suggests, is far more convenient for maps. It is not only the name, but the indexing to a Map is signifigantly less time consuming compared to a List. You can imagine your map as a cube, where you have to handle about half of the dots inside it, if you use List and probably only a narrow layer of it when you search by indexing a Map. There is a magnitude of difference. So, my answer here: Map is a key word towards the correct direction (assuming you want to do it in this way after reading on my answer).
2) Usage of a Map Server solution. This is probably too far from your approach, but entire frameworks are made for solving your type of question. An example is GeoServer. It has a ready made solution for the entire problem. It is a stable solution for the great big problem possibly in your hand: showing a map to a user from a source.
3) Sticking to the GDAL framework you were using, you could select slightly different py-file, like gdal_proximity.py and - wow! - you have a searching possibility in your hand! This particular one searches by a center point and a distance, but will do the stuff you need =)
There is a starting point, how I would make it. Could this serve for something?

Sounds to me like you are looking for something like an Interval Tree.
http://en.wikipedia.org/wiki/Interval_tree
I have implemented one of these in the past but only in one dimension. The Wikipedia reference mentions extensions to more dimensions.
Paul

Implementing a 'Waterfall' simulation in Java

I would like to implement a visualisation of this video in Java as experience to help me understand all of the 'troubles' in creating visualisations. I have some experience in OpenGL, and a good understanding of how to handle the physics involved. However, if anybody knows of any good game engines that may help (or at least do some of the heavy lifting involved in creating a visualisation of the above) I would be grateful.
Also, I noticed that the linked video must use many separate jets in order to operate in the way it does. Is it likely that it was created using something a little lower level such as C? Is it possible to use a higher level language like Java to control such a system?

Honestly, if you want to implement "just that", I think using a game engine is overkill. Just implement a simple particle engine on your own and you are done.
Seriously, that problem is not so difficult, any language can be used for it. The basic principle behind it is the same as behind steam organs or self player pianos. You have an input data that shows what the pattern to play is and you advance it in a given time.
Here is how I would build the basic control system. You take a black and white image. The width is exactly as wide as the number of "emitters" and the length is as long as the pattern needs to be. You read the image and start at the first line. You walk through each pixel in that line and if the pixel is black you emit a drop and if the pixel is white you don't. You then move in a given interval (maybe 25ms) to the next line and set the emitters accordingly.
The cool thing with images is that you can simply paint them in any graphic program. To get the current time to work you render the time into a image buffer in memory, then pass that into the above code. (You even get fonts if you like...)

You can use jMonkeyEngine.
JAVA OPEN GL GAME ENGINE