Network Analyses Tools in QGIS

in this video I'll be looking at net existence so now distances as the Profi but distance along a specific knit so to illustrate this I will look at the European road network so again I've taken data from natural earth misstep time it is the railroad and I've n clip and projected and I have my kappa souls from before that I can use so I have these different capitals that will match up of the data set so basically I just want to find out if you are living in one of the capitals how I'm working in it how far out and you live and still make it to the Kappas over in one hour train journey so what I basically want to do is I want to watch all of those knit the knit burger there's some things we have to know to start move first of all I don't know where natural F has got this network from I have lived in curve makeover I'm coming most of my 57 year life and I have never ever heard of every road that goes from muqam egg harbor an dr. Zoomer there's no ferry even that doesn't take we're a train on it it's Shh test strange so there's of course always some critics that you have to raise when you are looking at data this date has never been meant to do knit okay then this is another thing you have to check is when we do this have a minute but we have to check and the necklace is connected so that the lines connect and assuming and then they do so that is good so the network is relatively connect there are some there are some holes in there but that's fine yep so the other thing that is really important is that other points that we're going to use and starting point for our service a so how far we can live from the code Kerman has to be located on the rail room so indicia that this capital is not located on the river so we have to move the point of it if we look at Copenhagen here you can see that it is off by 2.3 kilometers SOCOM is all copy 100 meters from its railroad this one doing it good oh that's something about so perhaps contains one of the worst I might be something oh yeah so I mean you won so from then again here about so let's see two and a half kilometers is five kilometers is what we need to move so first thing is then to move these capitals to the real world so they match and this this is a to like if you don't have to do it manually so just like when the desires data you can also snap data afterwards so there's a a tool called snap to layer so let's both snap to grid and snap layer if I use a snap to layer and this case my input is my single point capitals in the right ordered system and my railroads so there and we looked at this tolerance and we decided that II need to move them up to and say five kilometers so five thousand meters and we can then do different things of how did we want to far as highs exist on to insert an extra node required and this is normally five me now this one this to explicitly quick and what we can see that if you look let's make sure that my snap is visible so if I look Copenhagen now you can see that areal coma hang has been moved up to this range trained for your road but this is not a course in public transport booming so you're instantly of that so we are basically good to go so now we need this network tool so there is these network analysis tools there's something a call from Laird something called from points and they call from points that means you can click on the screen at locations and it will work from there if they says from layer and you have to supply a layer that is for the purpose so in this case I'll be using for a layer because I will be losing my snapped cities so I will say I would like to work with my railroad I want to calculate the fastest group I want to use my snapped geometry as my notes I'm working for this is a bit strange normally in curious and Sewer means that we haven't entered anything in this run as maximum yeah we zoom in zero so guy said I want to do a travel time of civil and this is in seconds then they would be racial so I will set this to one hour so that 3,600 seconds I will so I could decide if I could both ways and don't look good to sit in of these there's a speech feel that I you by different speeds at the wheel they've been real tracked and I'll just sit and back to a default of 100 and don't not user each field and I'm basically ready so I listen run and it will start running and you'll do that by first generating a graph this is saying yeah that is the computer the structure that you can use for doing this type of analysis so it's building up and graph that you can transform who's a calculations on when it's done that it'll start doing it it doesn't take that long but I'll I'll just break yeah take a pause so once it's done the graph it will do the calculation of the networks and you can see this doesn't take a long time and I'll just close it and hopefully I can in my layers I'll find this service then I can drop it and I can give them nice colors so artist quality algorithm based on name and maker there's a 5/5 and we see this fine around each capital how far you can get into the capital by train one hour and of course Cummings is strange but that is because it's using this line here good that's all good there's just one little annoying thing that is that if I look at that abuse of this one it says that this is Helsinki what and if I do get there and sink II say move Twinkie but well that would be and in Helsinki it is oh [Music] right so although the software really is a nice soft one works super it has this one didn't annoying dog in it if there's a workaround because what it does it does write the coordinates down here if we look close at the corner you can see that it is a dismal value and then the five this world places and there's enough only for boys if either after go I did sir copy this for from reference and what I want to do is I want to create a data Butte that matches this because this coordinate is as you can see if I move my mouse oh yeah you see this is the coordinate that it reads up at the bottom of the screen so so it's using this star is basically the same coordinate as the start coordinate was here so I can if I can generate this attribute based on what about here I should be able to to join on this attribute so I can go into my snapped promontory here good properties of it and do a feel calculation where I will make new field all it on it could be a text I don't know if I should use that unlimited let's sit in here and set it to 15 s 450 and what I wanted to make is this or you can see we have the x coordinate and 2 5 + ry corner of to 5 after them ok so in order to do that I'll need to concatenate some numbers so I'll start with concatenate here say fun Lucy this is concatenate on the string that put strings - girl with a comma in between well I say concatenate and I want the x coordinate so this is darling drama tree there's a hit somewhere ah first okay we have to go beautiful yeah me because yeah it's giving us nothing is what let's see we won that rounded to a five-point the lay is a round to Leah and that round and take this one and rounds it to five then I want to concatenate it of a chroma a space but okay so comma space and crew single flips and round Oh my mic on it genomic week y-coordinate and they don't have to be around five five and I guess I need to close bracket so hopefully this is right I'll just take a copy in case it is a run okay and okay what the saves it the changes so now if I look at Copenhagen if I just open the attribute table on this one here and find open Hagan OS code and there so it should have a corpsman out here hopefully matches what I've got down there that's my starting now allows from I'll just check but this one yeah this is the one I want check if it matches so and Copenhagen and let's look much better it looks like they are matching so now hopefully I can go and say join this dataset of properties and choose join I want to add a join to my snap geometry and I want on this ordinate that is going to join room the start of my network the netbooks will start at the geometry point and therefore those two should match though it's really a bit of a workaround but hopefully if I now go up and change this one but now joins on the snap drama tree that's a joined attribute name we're classifying on that yeah and okay so now um this one hopefully if I about see open Hagen so now my map and you can see how slow is that blue collar it's it's flute right coming is red because I'm I tool on it Berlin as is let's also look right so I'm little trick about using the start coordinate to join into the data's it does solve that little issue that we're having of our network too so Emma tool is really a useful tool you have to have useful data of course or machine wash out as you say so we we have to look at some of these properties it has this little problem for doing it's joining the name from its point so we had to help it a bit until that his soul or someone tells me what I'm doing wrong but the trick about joining on the corner that work and I think I hope you found this useful it's a super cool tool to use and like my little video and hope to see you another one

Channel: Geoinformatics

Views: 2,886

Rating: 5 out of 5

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Id: szyyz9RnrZQ

Length: 18min 38sec (1118 seconds)

Published: Tue Apr 21 2020