I discovered recently plotly Dash and I am wondering if it's possible to do an aggregation map with it. In my understanding, the only map function is scattermapbox which does not allow such a thing. Am I wrong? If no, is there another way to do it? Maybe another framework? I'm mainly interested in doing a web app which presents side by side an aggregation map and a data grid (datatable in Dash) which interact with each other.
See here for an example of an aggregation map (or map cluster).
As of version 4.1.1 we support the new densitymapbox trace type, which does something quite similar: https://plot.ly/python/mapbox-density-heatmaps/
Related
I'm new to using ObjectBox, so I've been trying to do some experimenting with its query system to familarize myself with it. One of the queries I've been unable to do is a query comparing two properties. Ignoring the errors they throw, these are some examples of what I'm looking to do:
// Get objects where first number is bigger than second number
boxA.query(ObjectA_.firstNumber.greaterThan(ObjectA_.secondNumber))
// Get parent objects where one of its children has a specific value from the parent
parentBox.query().linkMany(ParentObject_.children, ChildObject_.name.equals(ParentObject_.favoriteChild));
I know based on this question that it's possible in Java using filters, but I also know that query filters are not in ObjectBox for Dart. One of the workaround I've been testing is querying for one property, getting the values, and using each value to query for the second property. But that becomes unsustainable at even moderately sized amounts of data.
If anyone knows of a "proper" way to do this without the use of Java filters, that would be appreciated. Otherwise, if there's a more performant workaround than the one I came up with, that would be great too.
There is no query filter API for Dart in ObjectBox, because Dart already has the where API.
E.g. for a result list write results.where((a) => a.firstNumber >= a.secondNumber).
I'm building a feature where I need to extract all coordinates of a selecetd road/path in Mapbox when it's clicked on. I've attempted to use the queryRenderedFeatures method, but it seems the result list is fragmented. By "fragmented" I mean that if you have a road or path which is clearly just one long path/road when rendered on the map, it often consists up of 4-5-6 or more features, and you cannot really work out from the feature collection how they're supposed to be connected (in order)
I then tried to use the Tilequery API, but it doesn't return any coordinates for LineStrings.
Is there any API - server or client side - in Mapbox, where you can provide an ID of a feature and retrieve the all coordinates for a road or path?
Thanks in advance :-)
I think you're really asking: "is there a way to access complete LineString features for data in Mapbox's tilesets", to which the answer is, no, not really - other than trying to reassemble them in the way you have tried.
For your own data, you could host it using Mapbox's Datasets, rather than Tilesets.
I'm trying to figure out what's the best solution to find all nodes of certain types around a given GPS-Location.
Let's say I want to get all cafes, pubs, restaurant and parks around a given point X.xx,Y.yy.
[out:json];(node[amenity][leisure](around:500,52.2740711,10.5222147););out;
This returns nothing because I think it searches for nodes that are both, amenity and leisure which is not possible.
[out:json];(node[amenity or leisure](around:500,52.2740711,10.5222147););out;
[out:json];(node[amenity,leisure](around:500,52.2740711,10.5222147););out;
[out:json];(node[amenity;leisure](around:500,52.2740711,10.5222147););out;
[out:json];(node[amenity|leisure](around:500,52.2740711,10.5222147););out;
[out:json];(node[amenity]|[leisure](around:500,52.2740711,10.5222147););out;
[out:json];(node[amenity],[leisure](around:500,52.2740711,10.5222147););out;
[out:json];(node[amenity];[leisure](around:500,52.2740711,10.5222147););out;
These solutions result in an error (400: Bad Request)
The only working solution I found is the following one which results in really long queries
[out:json];(node[amenity=cafe](around:500,52.2740711,10.5222147);node[leisure=park](around:500,52.2740711,10.5222147);node[amenity=pub](around:500,52.2740711,10.5222147);node[amenity=restaurant](around:500,52.2740711,10.5222147););out;
Isn't there an easier solution without multiple "around" statements?
EDIT:
Found This on which is a little bit shorter. But still multiple "around" statements.
[out:json];(node["leisure"~"park"](around:400,52.2784715,10.5249662);node["amenity"~"cafe|pub|restaurant"](around:400,52.2784715,10.5249662););out;
What you're probably looking for is regular expression support for keys (not only values).
Here's an example based on your query above:
[out:json];
node[~"^(amenity|leisure)$"~"."](around:500,52.2740711,10.5222147);
out;
NB: Since version 0.7.54 (released in Q1/2017) Overpass API also supports filter criteria with 'or' conditions. See this example on how to use this new (if: ) filter.
HI i'm working with the Java-Api of mongo-db.
I have to cast verry often like this
BasicDBList points = ((BasicDBList) ((BasicDBObject) currentObject.get("poly")).get("coordinates"));
which is not fun. Am i missing something or it is just the way to do it?
i think BasicDBObject should have functions like
BasicDBObject getBasicDBObject(String key)
BasicDBList getBasicDBList(String key)
Unfortunately, the current java driver is not perfect and it is difficult to avoid casting as you mentioned. However, java driver team is working on the next version and as far as I understand it will be completely rewritten.
In one of the mongodb meetup I heard that the new version will make use of asynchronous API, similar to the node driver. I guess we need to sit tight and wait for the next major release.
Alternatives, are (from Mongo Java drivers & mappers performances):
async Java driver
a library built on top of a driver, e.g. Morphia, Jongo, see POJOMappers
Looking at all the examples of Operational Transformation Frameworks out there, they all seem to resolve around the transformation of changes to plain text documents. How would an OT framework be used for more complex objects?
I'm wanting to dev a real-time sticky notes style app, where people can co-create sticky notes, change their positon and text value. Would I be right in assuming that the position values wouldn't be transformed? (I mean, how would they, you can't merge them right?). However, I would want to use an OT framework to resolve conflicts with the posit-its value, correct?
I do not see any problem to use Operational Transformation to work with Complex Objects, what you need is to define what operations your OT system support and how concurrency is solved for them
For instance, if you receive two Sticky notes "coordinates move operation" from two different users from same 'client state', you need to make both states to converge, probably cancelling out second operation.
This is exactly the same behaviour with text when two users generate two updates to delete a text range that overlaps completely, (or maybe partially), the second update processed must be transformed against the previous and the resultant operation will only effectively delete a portion of the original one, (or completely cancelled with a 'no-op')
You can take a look on this nice explanation about how Google Wave Operational Transformation works and guess from this point how it should work your own implementation
See the following paper for an approach to using OT with trees if you want to go down that route:
http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.100.74
However, in your particular case, I would use a separate plain text OT document for each stickynote and use an existing library, eg: etherPad, to do the heavy lifting. The positions of the notes could then be broadcast on a last-committer-wins basis.
Operation Transformation is a general technique, it works for any data type. The point is you need to define your transformation functions. Also, there are some atomic attributes that you cannot merge automatically like (position and background color) those will be mostly "last-update wins" or the user solves them manually when there is a conflict.
there are some nice libs and frameworks that provide OT for complex data already out there:
ShareJS : library for Node which provides all operations on JSON objects
DerbyJS: framework for NodeJS, it uses ShareJS for OT stuff.
Open Coweb framework : Dojo foundation project for cooperative web applications using OT