topic Re: Shortest distance matrix using GIS in Public Transit Questions

Shortest distance matrix using GIS

govindaDumaru — Mon, 10 Nov 2014 05:52:07 GMT

Please someone tell me if we can do shortest route analysis in gis just like Djkstra's or Floyd Warshal algorithm? Actually i want to get the shortest distance matrix of network.

Re: Shortest distance matrix using GIS

larryzhang — Mon, 10 Nov 2014 06:52:31 GMT

govinda,

Please refer to Path Distance & associated tools inside Distance toolset at http://resources.arcgis.com/en/help/main/10.2/index.html#/An_overview_of_the_Distance_tools/009z00000014000000/

and ArcGIS Help (10.2, 10.2.1, and 10.2.2)

Keep in mind that the GP tools under Distance toolset (least cost) is only used for two points (target, origin). If planning to create matrix of cost distance from more points (more targets, more origins), Python looping scripting is required….

Re: Shortest distance matrix using GIS

DanPatterson_Retired — Mon, 10 Nov 2014 09:04:18 GMT

Djkstra's Algorithm is used in the network analyst extension which isn't free but if you are with an educational institute, you may have it. Or there is network analysis online as well.

Re: Shortest distance matrix using GIS

govindaDumaru — Wed, 12 Nov 2014 00:34:45 GMT

Dear Larry Zhang and Dan Patterson

thanks for the reply. my follow up question is I have an problem of network (not all nodes are connected). I have distance in attributes for each edges (distance between nodes of network). I need to find the shortest distance matrix for all pair of nodes which I had posted above. I think cost distance matrix would help me (please comment if i am wrong). My next step is to find the minimum spanning tree (MST) from the computed cost distance matrix. Can GIS help me to find MST?

Best Regards

Govinda

Re: Shortest distance matrix using GIS

DanPatterson_Retired — Wed, 12 Nov 2014 00:53:49 GMT

I posted EMST code on the scripts site but I don't have the URL here I was called Spanning Tree tools, if you can't find it let me know and when I get to my "real" computer not this iThingy

Re: Shortest distance matrix using GIS

DanPatterson_Retired — Wed, 12 Nov 2014 02:23:26 GMT

Got it Spanning Tree Tools

Re: Shortest distance matrix using GIS

larryzhang — Wed, 12 Nov 2014 05:16:19 GMT

Thx, Dan,

Nice works.

However, really curious on the details how ESRI implements Djkstra's Algorithm in Network Analyst for efficiency…Can you instruct?

Govinda,

For network data analysis with ArcGIS 10.x, it would be nice also to do hands-on with 'The data that the ArcGIS Network Analyst tutorial exercises and workflows reference' at http://www.arcgis.com/home/item.html?id=d6bd91b2fddc483b8ccbc66942db84cb ...which offer deep insight on how ESRI Network Analyst tackles graph data for routing questions.

After those exercises, you can build a 'network dataset' and perform analyses on a 'network dataset' (rather than SHP file) with ESRI NA, including OD cost matrix.

By the way, please also refer to the 'Engineering Fast Route Planning Algorithms' (attachment)...

Re: Shortest distance matrix using GIS

DanPatterson_Retired — Wed, 12 Nov 2014 09:40:14 GMT

Larry... I am going on memory on the fundamentals behind NA only the NA team could elaborate. As for the exercises, I presume that they are contained in a gdb, I usually only develop using shapefiles since I use the base python code in other open source software and gdb's add another layer of checking I don't need

Re: Shortest distance matrix using GIS

larryzhang — Wed, 12 Nov 2014 10:01:03 GMT

Greeting, Dan,

Really nice! You are making many efforts to help others...

Re: Shortest distance matrix using GIS

govindaDumaru — Wed, 12 Nov 2014 10:34:33 GMT

Thanks a lot Dan.

Re: Shortest distance matrix using GIS

govindaDumaru — Wed, 12 Nov 2014 10:42:13 GMT

Thanks a lot Iarry.

Re: Shortest distance matrix using GIS

govindaDumaru — Wed, 19 Nov 2014 10:15:52 GMT

greeting all,

Please someone provide link for the tutorials data for arcgis 10.2.1. I have lost from my drive.

Re: Shortest distance matrix using GIS

larryzhang — Wed, 19 Nov 2014 11:39:42 GMT

For tutorial at ArcGIS Help (10.2, 10.2.1, and 10.2.2) and ArcGIS Help 10.1

For graph data for ESRI at http://www.arcgis.com/home/item.html?id=d6bd91b2fddc483b8ccbc66942db84cb

Re: Shortest distance matrix using GIS

govindaDumaru — Fri, 21 Nov 2014 10:16:39 GMT

Dear Iarry,

I think the link you provided above is for network analyst only. I am seeking for spatial analyst and others too.

Regards

Re: Shortest distance matrix using GIS

DanPatterson_Retired — Fri, 21 Nov 2014 13:04:01 GMT

here is the complete list of the tutorials including the spatial analyst .... scroll to find