Time series newbie here! I was following the section 2 of this tutorial about Kats.
While I was able to finish it I am still not able to display the whole time series with m.plot() as they show in the tutorial. I can display only the forecasted values.
Whenever I try to retrieve any information after the prediction, I get a
KatsEnsemble object is not subscriptable
Here my questions:
How can I have access to the results in a dataframe manner?
Is there also a way to retrieve the parameters used to create the forecast?
Related
Bitrix only brings up to 50 positions in the array list of all my data, this happens because of a security matter and, for what I've seen, can't be changed. So, to export the data from Bitrix to my dataware house (currently going through tranformation inside Pentaho) i need to get something near 50.000 arrays (keep in mind I can only get 50 at a time!!!! + they come at a non-organized id order) I need help to filter the ids in a order so my requests become easier. These are my parameters:
Print
If anyone know what kind of selection or filter I could use I'd really appreciate it!
below is my example graph
addV('user').property('userId','user2').as('u2').
addV('user').property('userId','user3').as('u3').
addV('group').property('groupId','group1').as('g1').
addV('group').property('groupId','group2').as('g2').
addV('group').property('groupId','group3').as('g3').
addV('folder').property('folderId','folder1').property('folderName','director').as('f1').
addV('folder').property('folderId','folder2').property('folderName','asstDirector').as('f2').
addV('folder').property('folderId','folder3').property('folderName','editor').as('f3').
addV('file').property('fileId','file1').property('fileName','scene1').
addE('in_folder').to('f3').
addE('in_folder').from('f2').to('f1').
addE('in_folder').from('f3').to('f2').
addE('member_of').from('u1').to('g1').
addE('member_of').from('u2').to('g2').
addE('member_of').from('u3').to('g3').
addE('member_of').from('g3').to('g1').
addE('has_permission').property('prm','view').from('g1').to('f1').
addE('has_permission').property('prm','view').from('g2').to('f2').
addE('has_permission').property('prm','view').from('g3').to('f3').
addE('has_permission').property('prm','view').from('u2').to('f1').iterate()
The use-case : Get both folders and files vertex as result where user3 have access to
im able to get either folder or files where user have access to, but not able to combine them.
below is the query which cam close but not exactly exptected resultset.
g.V().has('user','userId','user3').emit().until(__.not(outE('member_of'))).repeat(out('member_of'))
.outE('has_permission').has('prm','view').inV().as('f').inE('in').outV().as('a').select('a','f')
which results
==>[a:v[6144475224],f:v[164175920]]
==>[a:v[5202170056],f:v[204857480]]
the expectation is to get 3 vertexes with value Map, not just node ids.
f:v[164175920]
a:v[6144475224]
a:v[5202170056]
Could some one check and let me know how i can utilize union here.
tried below query
g.V().has('user','userId','user3').emit().until(__.not(outE('member_of'))).repeat(out('member_of'))
.outE('has_permission').has('prm','view').inV().inE('in').outV().map(union(valueMap())
this gives the file information only not the folder values.
You got it right in your comment query, only with few spelling mistakes which caused the error:
g.V().has('user','userId','user3').emit().repeat(out('member_of'))
.outE('has_permission').has('prm','view').inV().dedup()
.union(identity(),__.repeat(__.in('in_folder')).emit()).dedup()
This can be optimized a bit by moving the emit before the repeat and dropping the union:
g.V().has('user','userId','user3').emit().repeat(out('member_of'))
.outE('has_permission').has('prm','view').inV().dedup()
.emit().repeat(__.in('in_folder')).dedup()
Note that I used 'in_folder' instead on 'in' to match your sample data.
After working with neo4j and now coming to the point of considering to make my own entity manager (object manager) to work with the fetched data in the application, i wonder about neo4j's output format.
When i run a query it's always returned as tabular data. Why is this??
Sure tables keep a big place in data and processing, but it seems so strange that a graph database can only output in this format.
Now when i want to create an object graph in my application i would have to hydrate all the objects and this is not really good for performance and doesn't leverage true graph performace.
Consider MATCH (A)-->(B) RETURN A, B when there is one A and three B's, it would return:
A B
1 1
1 2
1 3
That's the same A passed down 3 times over the database connection, while i only need it once and i know this before the data is fetched.
Something like this seems great http://nigelsmall.com/geoff
a load2neo is nice, a load-from-neo would also be nice! either in the geoff format or any other formats out there https://gephi.org/users/supported-graph-formats/
Each language could then implement it's own functions to create the objects directly.
To clarify:
Relations between nodes are lost in tabular data
Redundant (non-optimal) format for graphs
Edges (relations) and vertices (nodes) are usually not in the same table. (makes queries more complex?)
Another consideration (which might deserve it's own post), what's a good way to model relations in an object graph? As objects? or as data/method inside the node objects?
#Kikohs
Q: What do you mean by "Each language could then implement it's own functions to create the objects directly."?
A: With an (partial) graph provided by the database (as result of a query) a language as PHP could provide a factory method (in C preferably) to construct the object graph (this is usually an expensive operation). But only if the object graph is well defined in a standard format (because this function should be simple and universal).
Q: Do you want to export the full graph or just the result of a query?
A: The result of a query. However a query like MATCH (n) OPTIONAL MATCH (n)-[r]-() RETURN n, r should return the full graph.
Q: you want to dump to the disk the subgraph created from the result of a query ?
A: No, existing interfaces like REST are prefered to get the query result.
Q: do you want to create the subgraph which comes from a query in memory and then request it in another language ?
A: no i want the result of the query in another format then tabular (examples mentioned)
Q: You make a query which only returns the name of a node, in this case, would you like to get the full node associated or just the name ? Same for the edges.
A: Nodes don't have names. They have properties, labels and relations. I would like enough information to retrieve A) The node ID, it's labels, it's properties and B) the relation to other nodes which are in the same result.
Note that the first part of the question is not a concrete "how-to" question, rather "why is this not possible?" (or if it is, i like to be proven wrong on this one). The second is a real "how-to" question, namely "how to model relations". The two questions have in common that they both try to find the answer to "how to get graph data efficiently in PHP."
#Michael Hunger
You have a point when you say that not all result data can be expressed as an object graph. It reasonable to say that an alternative output format to a table would only be complementary to the table format and not replacing it.
I understand from your answer that the natural (rawish) output format from the database is the result format with duplicates in it ("streams the data out as it comes"). I that case i understand that it's now left to an alternative program (of the dev stack) to do the mapping. So my conclusion on neo4j implementing something like this:
Pro's - not having to do this in every implementation language (of the application)
Con's - 1) no application specific mapping is possible, 2) no performance gain if implementation language is fast
"Even if you use geoff, graphml or the gephi format you have to keep all the data in memory to deduplicate the results."
I don't understand this point entirely, are you saying that these formats are no able to hold deduplicated results (in certain cases)?? So infact that there is no possible textual format with which a graph can be described without duplication??
"There is also the questions on what you want to include in your output?"
I was under the assumption that the cypher language was powerful enough to specify this in the query. And so the output format would have whatever the database can provide as result.
"You could just return the paths that you get, which are unique paths through the graph in themselves".
Useful suggestion, i'll play around with this idea :)
"The dump command of the neo4j-shell uses the approach of pulling the cypher results into an in-memory structure, enriching it".
Does the enriching process fetch additional data from the database or is the data already contained in the initial result?
There is more to it.
First of all as you said tabular results from queries are really commonplace and needed to integrate with other systems and databases.
Secondly oftentimes you don't actually return raw graph data from your queries, but aggregated, projected, sliced, extracted information out of your graph. So the relationships to the original graph data are already lost in most of the results of queries I see being used.
The only time that people need / use the raw graph data is when to export subgraph-data from the database as a query result.
The problem of doing that as a de-duplicated graph is that the db has to fetch all the result data data in memory first to deduplicate, extract the needed relationships etc.
Normally it just streams the data out as it comes and uses little memory with that.
Even if you use geoff, graphml or the gephi format you have to keep all the data in memory to deduplicate the results (which are returned as paths with potential duplicate nodes and relationships).
There is also the questions on what you want to include in your output? Just the nodes and rels returned? Or additionally all the other rels between the nodes that you return? Or all the rels of the returned nodes (but then you also have to include the end-nodes of those relationships).
You could just return the paths that you get, which are unique paths through the graph in themselves:
MATCH p = (n)-[r]-(m)
WHERE ...
RETURN p
Another way to address this problem in Neo4j is to use sensible aggregations.
E.g. what you can do is to use collect to aggregate data per node (i.e. kind of subgraphs)
MATCH (n)-[r]-(m)
WHERE ...
RETURN n, collect([r,type(r),m])
or use the new literal map syntax (Neo4j 2.0)
MATCH (n)-[r]-(m)
WHERE ...
RETURN {node: n, neighbours: collect({ rel: r, type: type(r), node: m})}
The dump command of the neo4j-shell uses the approach of pulling the cypher results into an in-memory structure, enriching it and then outputting it as cypher create statement(s).
A similar approach can be used for other output formats too if you need it. But so far there hasn't been the need.
If you really need this functionality it makes sense to write a server-extension that uses cypher for query specification, but doesn't allow return statements. Instead you would always use RETURN *, aggregate the data into an in-memory structure (SubGraph in the org.neo4j.cypher packages). And then render it as a suitable format (e.g. JSON or one of those listed above).
These could be a starting points for that:
https://github.com/jexp/cypher-rs
https://github.com/jexp/cypher_websocket_endpoint
https://github.com/neo4j-contrib/rabbithole/blob/master/src/main/java/org/neo4j/community/console/SubGraph.java#L123
There are also other efforts, like GraphJSON from GraphAlchemist: https://github.com/GraphAlchemist/GraphJSON
And the d3 json format is also pretty useful. We use it in the neo4j console (console.neo4j.org) to return the graph visualization data that is then consumed by d3 directly.
I've been working with neo4j for a while now and I can tell you that if you are concerned about memory and performances you should drop cypher at all, and use indexes and the other graph-traversal methods instead (e.g. retrieve all the relationships of a certain type from or to a start node, and then iterate over the found nodes).
As the documentation says, Cypher is not intended for in-app usage, but more as a administration tool. Furthermore, in production-scale environments, it is VERY easy to crash the server by running the wrong query.
In second place, there is no mention in the docs of an API method to retrieve the output as a graph-like structure. You will have to process the output of the query and build it.
That said, in the example you give you say that there is only one A and that you know it before the data is fetched, so you don't need to do:
MATCH (A)-->(B) RETURN A, B
but just
MATCH (A)-->(B) RETURN B
(you don't need to receive A three times because you already know these are the nodes connected with A)
or better (if you need info about the relationships) something like
MATCH (A)-[r]->(B) RETURN r
in my project we have an entity called Trip. This trip has two points: start and finish. Start and finish are geo coordinates with some added properties like address atc.
what i need is to query for all Trips that satisifies search criteria for both start and finish.
smth like
select from trips where start near 16,16 and finish near 18,20 where type = type
So my question is: which database can offer such functionality?
what i have tried
i have explored mongodb which has support for geo indexes but does not support this use case. current solution stores the points as separate documents which have a reference to a Trip. we run two separate quesries for starts and finishes, then extract ids of their associated trips and then select trip ids that are found both in starts and finishes and finally return a collection of trips.
on a small sample it works fine but with a larger collection it gets slow and it's like scratching my left ear with my right hand.
so i am looking for a better solution.
i know about neo4j and its spatial plugin but i couldn't even make it work on windows. would it support our use case?
or are there any better solutions? preferably with a object mapper written in php.
like edze already said Postgres (PostGIS) or SQLite(SpatiaLite) is what your looking for
SELECT
*
FROM
trips
WHERE
ST_Distance(ST_StartPoint(way), ST_GeomFromText('POINT(16 16)',4326) < 5
AND ST_Distance(ST_EndPoint(way), ST_GeomFromText('POINT(18 20)',4326) < 5
AND type = 'type'
For example you make a search for a hotel in London and get 250 hotels out of which 25 hotels are shown on first page. On each page user has an option to sort the hotels based on price, name, user-reviews etc. Now the intelligent thing to do will be to only get the first 25 hotels on the first page from the database. When user moves to page 2, make another database query for next 25 hotels and keep the previous results in cache.
Now consider this, user is on page 1 and sees 25 hotels sorted by price and now he sorts them based on user-ratings, in this case, we should keep the hotels we already got in cache and only request for additional hotels. How is that implemented? Is there something built in any language (preferably php) or we have to implement it from scratch using multiple queries?
This is usually done as follows:
The query is executed with order by the required field, and with a top (in some databases limit) set to (page_index + 1) * entries_per_page results. The query returns a random-access rowset (you might also hear of this referred to as a resultset or a recordset depending on the database library you are using) which supports methods such as MoveTo( row_index ) and MoveNext(). So, we execute MoveTo( page_index * entries_per_page ) and then we read and display entries_per_page results. The rowset generally also offers a Count property which we invoke to get the total number of rows that would be fetched by the query if we ever let it run to the end (which of course we don't) so that we can compute and show the user how many pages exist.