0:00Hey, it's Tim here and in 2020.4 Tableau
0:03have added the ability to now work with
0:05different
0:05predictive modeling functions inside of
0:08Tableau Desktop and the browser as well. To
0:11show you
0:11this I'm actually going to start off in
0:12Tableau Desktop. We're going to connect to
0:13Superstore
0:14Sales and we're going to build a very basic
0:16line chart. If you haven't seen my other
0:19video
0:19on extending the date access range that is
0:21a really useful video to watch before you
0:23watch this one because I will be doing that
0:25a little bit here and it's just good
0:27context
0:27for what's going on in this video so I won
0:29't be covering it so go watch that video and
0:32I'll see you back in a bit. I'm going to
0:34connect to Superstore Sales here and we're
0:36going to
0:36hop right in essentially. We're going to
0:38wait for this to load and we'll have our
0:40data set
0:40pretty much ready to go. Now the key thing
0:42I want to do here is just build out a
0:44simple
0:44line chart and I'm not going to try and do
0:47too much education of predictive models
0:49here.
0:50I'm just going to try and show you the
0:52predictive models and show you what's new.
0:54So the first
0:54thing I'm going to do is drag sales onto
0:56rows and then I'm going to drag order date
0:59onto
0:59columns. That by default brings in a
1:01discrete year if that makes sense. I'll
1:03make it a continuous
1:04month and that gives us this nice timeline
1:07we've got here. Now in 2020.3 they added
1:11the
1:11ability to do model quantile and model
1:14percentile. And essentially these are sort
1:17of methods
1:17of doing predictive analysis. They're sort
1:19of two functions as you would call it in
1:21Tableau
1:22terms. And so what we're going to do is we
1:23're actually just going to use one of them.
1:25We're
1:25going to use the model quantile one because
1:28that is actually quite a straightforward
1:30one
1:30to show on the screen and explain. The
1:32percentile one is more of a range based
1:35sort of predictive
1:36model. So with the quantile one what we can
1:39do is we can choose the median and then we
1:41can see how that actually behaves because
1:43the median is supposed to reflect
1:45essentially
1:46the middle of the data. So 50% of the data
1:48should fall above it and roughly 50% should
1:51fall below it according to the model. So
1:53let's go ahead and create a calculation and
1:55we're
1:56just going to bring this here into the
1:57middle and we have our calculation window
1:59ready to
2:00go. Now one of the things you can do is if
2:02you don't know how to write these functions
2:03you can just type in the name model in this
2:05case and you'll see model percentile and
2:08model
2:08quantile. We're going to use quantile here
2:11in this particular case and it's going to
2:13actually give us some hint as to how the
2:15model should be written if that makes sense
2:17. So
2:18what I'm going to do is I'm just going to
2:20write it as if I'm not putting any
2:21variables
2:22into this. I'm just using the standard
2:24function which in this case is a linear
2:26regression.
2:27So you can see this sort of nomenclature
2:30here. First thing it wants is the quantile.
2:32So if
2:32I just type in 0.5 for the median that's
2:35going to work quite nicely and then the
2:37target expression
2:38is the sum of sales in this case. In the
2:40other video you'll see that I suggested
2:42that we
2:43shouldn't be actually typing this out. I'm
2:45quite comfortable with Tableau so I know
2:46how
2:46to do this myself but if you want to make
2:48sure you don't get it wrong then what you
2:51want to do is drag them from the menu bar.
2:52In fact that's what I'm going to do for
2:54this
2:54next one because the predictor expression
2:56in this case is the month date and I need
2:58to make sure it's the correct one. So let
3:00me just click and drag here. I'm holding
3:02command
3:02on the Mac while I do that. On a Windows it
3:04's control and we pretty much have
3:06everything
3:07we need here. The last thing is obviously
3:09this date truncation is causing us a
3:11problem.
3:12You'll see here we get the error cannot
3:13makes aggregate and non aggregate arguments
3:15with
3:16this function. We've got sum of sales here
3:18which is an aggregate. The model is
3:21basically
3:21encapsulating all of this so the thing we
3:23actually need to fix here is the date trunc
3:25ation.
3:26So the way to sort of make this an
3:27aggregation is to throw an attribute at it
3:29essentially.
3:30So ATTR that's a good old trick. If you've
3:32used Tableau for a while you know that
3:34trick
3:34basically. If you need to aggregate text or
3:37something like that attribute is an
3:39absolute
3:39winner. In this case it makes a lot of
3:41sense because we're working with dates and
3:43the dates
3:43alike. I think of them as buckets so we
3:45need to actually just attribute it to the
3:47whole
3:48month not just the particular day if that
3:50makes sense. I mean I probably murdered
3:52that
3:52description so let's not go into that in
3:54this video maybe another video on that but
3:56long
3:56story short we need to make sure that it's
3:59all an aggregate. So here we have our model
4:01and I'll just call this example one and I'm
4:05actually going to call this linear
4:06regression.
4:07I'm just going to call this linear R
4:09because I know it is. I'll show you how I
4:12know that
4:13it is in a second so hit apply and what we
4:15'll do is we'll actually put this onto the
4:17canvas
4:17and I won't close the calculation window so
4:20let me just make this a little bit smaller
4:23and I'll bring this down here just off
4:24screen and we'll actually drag the example
4:27one right
4:27next to sales and this will actually draw
4:30another chart. You can see the two lines
4:33there
4:33and what we can do is we can actually dual
4:35access these so that they lie on top of
4:37each
4:37other. The last thing to do of course is to
4:39synchronize the axis so it's really really
4:41clear and now we have it. So the whole
4:44point of this linear regression and the
4:46quantile
4:46that I've chosen is that essentially this
4:48model predicts that half the values are
4:51going
4:51to fall above and below so it's the exact
4:54middle of the data set and it generally
4:56looks
4:56at the data set in a very simple way. Now
4:59the reason I know this is a linear
5:00regression
5:01is if I actually go to the Tableau
5:02documentation on this where they have
5:04advice on choosing
5:05a predictive model this is actually new in
5:072020.4 they actually have this page and the
5:10default function that came with model quant
5:13ile and model percentile was actually the
5:15linear
5:16regression so you don't actually need to
5:18specify it because it is the actual default
5:20. So if
5:21I go back to my calculation here and I just
5:23click put my mouse in here you'll see that
5:26if you look at this really really long
5:28expression here that the model has a
5:30different way of
5:31describing the model if you want to. So you
5:33can either do it the simple way which is on
5:35the left quantile target expression
5:38predictor expression or you can do model
5:41and then model
5:42quantile target expression and predictor
5:46expression. So model quantile target
5:49expression and predictor
5:51expression so this one on the right
5:53actually has the specificity of the model
5:55you want
5:56to run so we actually need to do that in
5:57this case to make things work a little bit
6:00better.
6:00Now in order to do that I'm actually going
6:02to split this out onto multiple lines it's
6:03a little bit easier to see. Okay so let's
6:05clean up this calculation I'm just going to
6:07go up to this 0.5 I'm actually going to go
6:10onto a separate line like so then I'm going
6:12to go to the sum and I'm going to open up a
6:14separate line then I'm going to go to the
6:16attribute I'm going to open up a separate
6:19line again and I'm going to go to the final
6:22I think that's pretty much it actually I
6:24don't need to do any more of that what I
6:26can do
6:26is I can put these brackets in new lines so
6:28that it's easy to know where things start
6:31and where they end. If you look at this
6:34date truncation actually what we can do is
6:36this
6:36should actually go back one here because
6:39this is all just one function and actually
6:41that's
6:42the last bracket here that actually we
6:44started over there. One thing you could do
6:46if you've
6:46got a bit of OCD is do that so that the
6:48brackets are in line then you can of course
6:51highlight
6:51everything and just tab them in one so that
6:54everything's sort of nice and neat. So this
6:57is great one of the new features in 2020.4
7:00is the ability to do block comments so the
7:02way you do that is you could do something
7:05like this forward slash star say something
7:07and then say more here and more and then
7:11you can close out on a new line with that
7:14and
7:15that actually does a block comment it's a
7:16really cool feature check out my video on
7:18that but here what I now want to do is add
7:21in the new functionality if I click in here
7:24you'll see that it gives me this ability to
7:26add a model so what I'm now going to do is
7:28I'm now going to specify a model. Okay in
7:31order to specify a model we just need to
7:32basically
7:32create a new line and I'm just going to do
7:35a double space there I'm just going to type
7:37in model and I'm going to do equals and I'm
7:40just going to do speech marks because that
7:42's
7:43typically what you do to enter text and I'm
7:45going to do a comma just to make sure that
7:47's
7:47working now the calculation still thinks it
7:50's got an error I think what I've done here
7:52is
7:52I've actually put the speech marks in the
7:58wrong place so if I do that there and then
8:04if I just type in linear in here let's just
8:07make sure this is correct sometimes I
8:09forget
8:09the notation if I get it wrong we can go to
8:12the documentation and search there we go I
8:14think I've got it right so what it didn't
8:16like is it didn't like the space that I had
8:18there before and then previously I didn't
8:20put the speech marks in the right place so
8:22it's very it's very fussy it's only going
8:24to sort of be happy once you've put
8:25everything
8:26in exactly the correct place now you can
8:28see here I've rewritten this in the new
8:31format
8:31I'm just going to move it here to the top
8:33right so we can see the chart more clearly
8:34here at the bottom and if I just hit apply
8:36you'll see that nothing changes because
8:39this
8:39is the same model we were using before it's
8:41actually the default model okay so now we
8:44can actually start playing with some of the
8:46new models in 2020.4 so the new one one of
8:48the new ones is a regular regular I can't
8:51even say this a regularized oh man this is
8:54a real tongue twister let's see how many
8:56times it takes for me to get this right
8:58regular
8:58regularized linear function there we go I
9:02got it so this one is actually quite easy
9:05to type thankfully you don't have to type
9:07that sort of mouthful you can just type in
9:08rl if I was to say in better terms this
9:11model will find a line that generally fits
9:14the trend
9:15it's not as fussy as the linear regression
9:17in terms of following the trend if that
9:19makes
9:19sense so let's just type in rl and hit
9:22apply and you'll see that it's ever so
9:25slight change
9:26there if I just do if I just copy this out
9:28here what I can actually do is I can be
9:31really
9:31smart I can actually comment out that line
9:34and then what I can do on a new line is
9:36copy
9:37this and what we can do is actually just
9:39comment in and then comment out pieces of
9:43the of the
9:43calculation so let's just paste this here
9:46and we can say that this is linear okay and
9:49now if I hit apply because this has been
9:51commented out it won't work so if I do it
9:53apply you'll
9:54see the line shifts ever so slightly it's
9:56the most subtle of changes and then if I
9:58cross
9:58that out and go down to a new line double
10:00forward that it's commented out you see the
10:03line changes back so it's probably not a
10:05good example here this probably will work
10:08better
10:08in a slightly different sort of time frame
10:11but essentially that model is is now
10:13available
10:14for you to try and then the last one we're
10:16going to try is a gaussian model so let's
10:19just go in here and hit enter go in again I
10:21'm going to use a double space I'm going
10:24to comment out the first one go forward
10:26slash forward slash and then comment out
10:29the last
10:29one dash dash and what I want to do here is
10:33the terminology for this I forget this so
10:36I'm just looking up on my second screen
10:39here is gp so gp is the actual expression
10:42so let's
10:42go ahead there and hit apply and you can
10:45see that this is a very different model it
10:47actually
10:48pretty much follows our trend in a very
10:51interesting way and so there we have it we
10:53have the two
10:54new models that have been added the regular
10:58ized I still can't say regularized linear
11:01model
11:01and the gaussian model that have been added
11:03alongside the linear model which was the
11:05previous
11:05default and you can of course use this for
11:07the model quantile and model percentile
11:10functions
11:10that are now available as predictive
11:13functions inside of the calculation window
11:15or tableau
11:16desktop or even in the browser so that's
11:17pretty much it that's the feature in a
11:19nutshell I
11:20highly encourage you to actually go to
11:22tableau's documentation I know I'm a little
11:24bit of a
11:25shill for tableau's documentation I'm
11:27probably a shill for tableau but there's
11:30great great
11:30content here in the documentation I can't
11:33emphasize enough how often people come to
11:35me for help and I just go to the
11:37documentation I feel really bad when I send
11:39people the document
11:41as if to suggest that they they hadn't
11:43thought to read it but it is an easy
11:45mistake to make
11:46you wouldn't expect a software company to
11:48go into this much detail in terms of
11:50describing
11:51features that you know are actually
11:53generally not exclusive to the piece of
11:55software these
11:56models are are not necessarily exclusive to
11:59tableau they can be found in any
12:00statistical
12:01tool pretty much but as you can see here
12:03tableau have done a nice job of really
12:05summarizing
12:06when you can use this model so linear
12:08regression is the default as I said to you
12:10earlier on
12:10use when you have only one predictor and
12:12the predictor has a linear relationship
12:13with your
12:14target use the regularized linear
12:16regression I mean they've got to come up
12:18with a better
12:19name for that come on use when you have
12:21multiple predictors especially when the
12:23predictors
12:23have linear relationship to the target
12:25metric and those predictors are likely
12:27affected by
12:28similar underlying relationships or trend I
12:30mean I just zoned out after the first
12:32sentence
12:32there but if you're into this stuff and you
12:34're being asked are you being pressed to
12:37start
12:37to use these functions or use these
12:39capabilities in some of the way you do your
12:41work then it's
12:42nice to be able to have them available to
12:44you and of course you can then start to you
12:46know put them out there and see how people
12:48challenge the models or choose which model
12:50is the best one and so on and so forth but
12:52it's just great to have these features
12:54there
12:54and you can see that you know it's
12:56reasonably easy to add them to tableau to
12:58be brutally
12:59honest it's not a ton of work and not like
13:01R or something else where you have to do a
13:03lot of data framing and sort of description
13:06of what you're about to do and a tableau
13:08calculation
13:09is super super simple so anyway I'm r
13:11ambling on now let's end this video and if
13:13you've
13:13enjoyed the video you know what to do if
13:15not drop a comment below let me know what
13:18you'd
13:18like to see instead or send it to someone
13:20you don't like they might appreciate it
13:21more
13:22thank you I'll catch you in the next one.
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