Buffer lines or paths in Tableau | Buffer Linestring enhancement | New in tableau 2024.1

0:00In Tableau 24.1, there's a new feature that

0:02allows you to use the buffer function on

0:04line string geometry objects inside of

0:06Tableau Desktop.

0:07There's also a bit of a non-story to this

0:09feature, so as ever, let's get stuck in.

0:12So the non-story here is that this feature

0:13doesn't actually appear anywhere in the

0:15product marketing.

0:16If you go to the Tableau features release

0:18page and you go to Tableau Desktop or Table

0:20au Web Authoring, you can just go ahead and

0:21filter this over here.

0:23Select Tableau Desktop as an example. You

0:25won't see this being mentioned here.

0:27But when Tableau 24.1 came out, I saw a

0:30post by Mark Reid, and Mark always does a

0:32fantastic job.

0:33If you want to learn everything there is to

0:35know about spatial capabilities inside of

0:37Tableau, Mark Reid's blog and Mark Reid's

0:40video channel is the place to go.

0:42YouTube channel even. And he posted this

0:44little feature and I thought, "This is

0:45interesting. I thought the buffer function

0:47already existed."

0:48And it does. The buffer function previously

0:51was able to do this specifically with data

0:53points.

0:53So in essence, what we're talking about are

0:56geometry points rather than geometry, lines

0:58, strings, and polygons.

1:00So in this specific case, what this feature

1:02actually is is an enhancement.

1:04And I've made a big deal about the fact

1:06that a lot of features in Tableau in the

1:07past have just been enhancements, not

1:09really features.

1:10And it's kind of interesting because on

1:12this particular case, Tableau themselves

1:14acknowledge this as an enhancement.

1:16So if you go to the Tableau release navig

1:18ator, it says that for Tableau 24.1, this

1:21specific enhancement is actually just an

1:23update to the existing capabilities.

1:25It wasn't possible to do this before. Now

1:27it is possible. So is this an enhancement

1:29or a new feature?

1:31You tell me. Let me know in the comments

1:32below.

1:33Anyway, the feature is here and I'm going

1:35to show you how to use this with a specific

1:37dataset for the London Marathon.

1:39If I go over to my file system here, you'll

1:41see that I have a shapefile.

1:42What I did is I actually downloaded the

1:44London Marathon route as a GPX file.

1:46GPX file is essentially what's created when

1:48you do a run on your smartwatch or any

1:50sports tracking watch.

1:52And I turned it into a shapefile using

1:53website.

1:54You could probably do the same thing with

1:56your own GPS trace.

1:56Having done that, I downloaded that onto my

1:58computer and you can see that these are the

2:00base files here.

2:01Now a shapefile is kind of interesting

2:03because you actually need all the

2:04constituent parts.

2:05But the actual file that we connect to is

2:08this one, .shp file.

2:09I'll put a link to these files so you can

2:11follow along in this video if you want to.

2:13And I'll also publish this visualization

2:15that I'm going to build on Tableau Public

2:16as well.

2:17So let's go ahead and head to Tableau

2:19Desktop where we can actually start working

2:20with this.

2:21So to do this, we're going to hit on this

2:23spatial data type here when we go and

2:25connect to a file.

2:26This actually is something you can do on

2:28Tableau Public as well. Absolutely fine.

2:30We'll go ahead to my desktop here and we'll

2:32go ahead to the London Marathon page.

2:34You can see here we have the shapefile. Let

2:36's go ahead and select that straight away.

2:38Once we've done that, you'll see that we

2:40connect to it here.

2:41Now I'm just going to move my face up to

2:42the right because what I want to highlight

2:43to you

2:44is that this geometry is indeed a line

2:46string.

2:47So to show you that, we have to go and look

2:49for the geometry column in our dataset.

2:51The way shapefiles work means that the

2:53geometry column actually carries a lot more

2:55information

2:56than just one row of data. But you can see

2:58here just on the right hand side that it is

3:00actually

3:01a geometry on the far right hand side. So

3:03that's exactly what we're looking for.

3:04Now we can go ahead and use this inside of

3:06Tableau. We'll go ahead and click on sheet

3:09one.

3:09If you're wondering where that is, that's

3:11on the bottom left here.

3:11So let's go ahead and click on that. And

3:13now we're ready to visualize our chart.

3:16Now this function is super easy to use. I

3:17've actually done a video on this function

3:19already.

3:20If we go ahead and double click the

3:21geometry, you'll see that it draws the

3:23geometry straight

3:24away. Let's put my face down here so it's

3:25out of the way. Let's hide the show me

3:27function on

3:27the right. And you can see that it's

3:29already there. It's dead easy. That's

3:30almost all we

3:31need to do. Now to make this map a little

3:33bit nicer, just going to spend a little bit

3:35of time

3:35formatting this. So I can never remember if

3:37it's background layers or map options,

3:39but I think it's background layers. Yes,

3:41that's the one you can go ahead and choose

3:43something

3:43a little bit nicer. Let's choose streets.

3:46It gives us a much richer, nicer chart.

3:48We can actually make this a little bit more

3:49interesting. Let's see if I can

3:51dial up the size of this path as well, just

3:53to make it a little bit brighter. And

3:55because this

3:55is a route, let's make it red. Let's make

3:58it a really rich red and make it stand out

4:00compared

4:00to the chart. And then what we can do is we

4:02can wash out the map a little bit more,

4:04just so that

4:04it's a little bit more obvious. So there we

4:06go, done some formatting, we've made this

4:07look nicer.

4:08Now we can actually get back to the agenda,

4:10which is to do the buffer function. So to

4:12do this,

4:13I'm just going to go ahead to the top right

4:14here, and I'm going to create a calculated

4:16field.

4:16You don't have to do that, you could do it

4:18another way. But this is the way I like to

4:19do it.

4:19And here you can see we've got this

4:21calculation window that's modal modal just

4:24means that it's

4:24floating. So we can go ahead and sort of go

4:26ahead and start typing the function. So if

4:29you're new to

4:30functions in Tableau, go ahead and check

4:32out my functions playlist, I have over 30

4:34videos and

4:34functions there. But we just go ahead and

4:36type buffer and you'll see that Tableau

4:38gives us a

4:38hint for the function. And it immediately

4:41shows us how to use that function. It wants

4:43the geometry,

4:44and it wants the number, then it wants the

4:46units. And what a buffer does is it draws a

4:48boundary

4:49around the object. So the units are going

4:51to be distances, meters, feet, kilometers,

4:54you can use

4:55other factors as well, Mars as an example.

4:57So for this one, the geometry want is

4:59actually called

5:00geometry, you can see that that's this

5:02field right here. So let's go ahead and

5:04just go back in here

5:05and just type geometry. You'll see the auto

5:07complete comes up geometry selected, then

5:09we can

5:10hit a comma, we're going to want to add 100

5:12meters to this geometry. So I want to

5:14create 100 meter

5:16boundary around the London marathon route

5:18for the purpose of maybe creating zones

5:20that are going to

5:21be used for specific activities around the

5:23event. So let's go ahead and type 100. We

5:26'll then go ahead

5:26and type M and to do this M on its own is

5:28not enough, you have to put this in speech

5:31marks.

5:32So we'll go ahead and delete that and just

5:34type in M. And now that's actually ready,

5:36you'll see that

5:36Tableau tells us that this function is

5:38correct, it tells us down here that the

5:40calculation is valid.

5:41We're now ready to go ahead and use this

5:43and we'll call this 100 meter zone. So let

5:47's call this

5:48zone. And we'll hit apply. Okay, now I'm

5:50actually going to duplicate this straight

5:53away. And I'm

5:53just going to go create another zone

5:55because the great thing about this is you

5:57can you can actually

5:58do a couple of things with it, we'll create

6:00a five 500 meter zone. That's about right.

6:03And we'll call

6:03this as such. So we'll see Tableau complain

6:05, then I'm using the same name. And then we

6:07'll go ahead

6:08and change that to five. And now it's

6:10absolutely fine. And then we'll do a

6:12kilometer zone. That's

6:13the last one that we'll do. So we're going

6:15to stack all three of these geometries on

6:16top of each other

6:17to create a sort of layered visualization

6:20of zones around the particular specific

6:22route. This is super

6:23handy. And one of the things you can do, of

6:26course, is you can sort of merge this with

6:28other functions

6:29inside of the spatial capabilities in Table

6:31au. So we'll go ahead and hit apply, hit OK.

6:34And now

6:34we've got the different zones, I didn't

6:36actually name that as zone. So let's go

6:38ahead and just

6:39rename that in here. So we'll go ahead and

6:41type zone. Perfect. Now what we can do is

6:43we can start

6:44dragging those zones onto the map. So let's

6:46go ahead and drag 100 meters zone and you

6:48'll see

6:48that a zone appears around the map, we can

6:51of course go and change the color. So we

6:53can make

6:54it yellow. Let's do that as an example, you

6:56can see that it's right there. Now is a

6:58critical thing,

6:58because we're using the map players

7:00capability in Tableau, you'll see that the

7:02geometry zone we

7:03started with is at the bottom. And the 100

7:06meters zone here is at the top. And if we

7:08want to layer

7:08these so that the layering actually works,

7:10what we want to do is actually change the

7:12order of the

7:13surround. So I'm going to go ahead and drag

7:15the other zones that we need here onto the

7:17chart,

7:17then we'll reorganize things in the way

7:19that makes sense. You'll see what I mean in

7:21a very

7:21brief moment. So let's go ahead and drag

7:23500 meters and onto the chart, you'll see

7:25that layers in.

7:26And then let's go ahead and drag a kilomet

7:29er on top. And so what you can see here is

7:31that we've

7:31actually got the zones quite clearly laid

7:34out here and almost sort of going in

7:36descending order. So

7:37it actually should be the other way around

7:39what we actually want is to go in this

7:40direction over

7:41here. So let's go ahead and start doing

7:43that. So what I'll do is I'll just go ahead

7:45and drag it.

7:46And you can see that I'm dragging it up and

7:47down the marks pane, geometry goes to the

7:49top, the red

7:50line comes through. Now that's starting to

7:52work nicely. Let's go ahead and put the 100

7:54meter one

7:54next and the 500 meter one. Now you can

7:57kind of start to see these layers working.

7:59The next thing

8:00we probably need to do is to sort of make

8:02the formatting a little bit nicer because

8:04it's

8:04absolutely awful right now. And so what we

8:06do as we go further out, we'll make the

8:08zones probably

8:09less interesting just that it's super clear

8:11. And there you go, we've kind of got this

8:13really strange

8:14layered effect going on. Now, what you can

8:16do is you can start to wash out specific

8:18details. So if

8:19you don't want them to be sort of so over

8:21bearing, you go into the color change, play

8:23around with the

8:24sort of different markings, and then go

8:27ahead and just apply the formatting that

8:29you want to really,

8:30really dial this in. Now don't forget that

8:32once you've done this, you can of course

8:35play around

8:35with this with parameters and actions. And

8:38so you can make this a truly interactive

8:40sort of

8:41capability that you're working with. So

8:43here we have the route. And now as we use

8:45this map,

8:45if I just zoom into specific parts of

8:47London, we can use this to start to

8:49identify areas visually

8:51here on the map that we maybe need to be

8:53prepared to do specific types of activities

8:55. And we can

8:56just quickly use this. Now, there is a

8:58little bit of theory here in that these

9:00zones, these distances

9:02are not exactly pinpoint accurate, there's

9:04a little bit of maths going on behind the

9:06background,

9:07which means that you have to sort of factor

9:08that in. But over this kind of distance is

9:10perfectly

9:11fine, you're not going to get any

9:12distortion that's going on. So that's it.

9:14That's pretty much

9:15a feature in a nutshell. And we've got a

9:17bit further show to you a few more other

9:18capabilities

9:19around mapping. If you've enjoyed this

9:21video, you know what to do hit subscribe,

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9:35really appreciate it. I'll catch you in the

9:37next one.