I have a database of users and each user record has "User ID" and "Group". After filtering out a chunk of the records, I'd like to sum the number of users within each group. Currently I am doing that with the calculation:
{FIXED[Group]:SUM([Number of Records])}
The problem here is this calculation appears to ignore any records that I've filtered out and just gives a total count per group from all of the unfiltered data.
Is there a quick way to sum the number of visible users in each group after applying a filter?
The easiest way of solving this would be to take advantage of the order of operations in Tableau.
The issue you are having at the moment is the LOD calculation is performed prior to a dimension filter.
If you want to calculate a field at a different level of detail then the view than a LOD is still the way to go. All you need to do is force tableau to apply the filters before calculating the fixed calculation.
In order to do this change your filters to a context filter. This is done by right clicking on the filter and selecting "Add to context. You will see the filter change from blue to grey.
Your calculated field should now be sensitive to any context filters.
Find out more here
Related
I want to take an average of the whole data and then filter that data and take another average and then compare the two. Any help is appreciated.
Translating on sample superstore-
The following expression will give average of sales for entire data
{ Avg([sales])}
across all rows. The following expression will, however, give category wise average sales
{FIXED [Category]: avg([sales])}
across all rows again. If you want to apply filters on these calculations add that filter to context but be cautious that the filters will then filter the data used for calculations in both the expressions. If you just want to filter data for viewing purpose and not the calculations dont add the filters to context.
I am trying to show the change in moving average by county on a map.
Currently, I have the calculated field for this:
IF ISNULL(LOOKUP(SUM([Covid Count]),-14)) THEN NULL ELSE
WINDOW_AVG(SUM([Covid Count]), -7, 0)-WINDOW_AVG(SUM([Covid Count]), -14, -7)
END
This works in creating a line graph where I filter the dates to only include 15 consecutive dates. This results in one point with the correct change in average.
I would like this to number to be plotted on a map but it says there are just null values.
The formula is only one part of defining a table calculation (a class of calculations performed client side tableau taking the aggregate query results returned from the data source)
Equally critical are the dimensions in play on the view to determine the level of detail of the query, and the instructions you provide to tell Tableau how to slice up or layout the query results before applying the table calc formula. This critical step is known as setting the “partitioning and addressing” for the table calc, sometimes also as setting the “compute using”. Read about it in the online help for table calcs. You can experiment with using the Edit Table Calc dialog by clicking on the corresponding pill.
In short, you probably have to a dimension, such as your Date field to some shelf - likely the detail shelf, and the set the partitioning and addressing, probably to partition by county and address by state.
If you have more than a couple of weeks of data, then you’ll get multiple marks per county. You may need to decide how to handle that on your map.
I would like to sort this scatter plot, which is summarized with a Band that includes Minimum, Average, and Maximum.
I would like to sort it in 2 ways:
by Average
by Widest Range (ie difference between Minimum and Maximum values)
Tableau Public workbook
If you can't view this or I'm not allowed to post external resources on stackoverflow, then perhaps you can show me on this screenshot what I would click to get started on the following sort
Also, bonus question, is there a way to create a control for the user to toggle between the 2 sort methods in the same chart? Or do I have to duplicate the chart with a different sort type for each?
One note is that I only have Tableau Public version since I'm evaluating the product. Until I get a paid version, I can't open a workbook file unless you publish it to Tableau Public cloud. But rather than give me the workbook answer, I would just appreciate it if you gave me instructions to do this as this is more of a learning exercise.
Thanks!
Somewhat unfortunately, you'll have to replicate the min,avg,max by creating 3 calculated fields. Tableau cannot operate on the values placed on the view via reference lines.
These calculations might look something like these:
{Fixed [Cwe]: Min([Cvss Score])}
~
{Fixed [Cwe]: Avg([Cvss Score])}
~
{Fixed [Cwe]: Max([Cvss Score])}
In general, from there, you should pretty easily be able to apply them to the view and sort. Average will be easy. The difference between Min and Max will just need a subtracting calculated field to sort by. Once they're on the view, I'd put them as a dimension (column) to verify that the numbers look correct.
Take note that LOD calculations take place before filtering, so you'll want to put the Cvss filter you have there 'on context' by right clicking it and clicking 'add to context'
Here is how I would complete the sorts:
Starting with all the above calculations on 'Rows' and ensuring that they are 'Dimensions' (Blue).
After right clicking "Sort..." on [Sub-Category] on 'Rows'. Select which field to sort by.
From there, the calculated fields can be taken off the rows column. (They were only there in the first place to ensure that you could check that the sorts took place. They don't actually need to have been there in the first place.)
Can I cause Tableau to require a certain number of underlying data points before plotting a point on the graph?
For example, here's a graph showing average moods over the course of the day on Tuesdays:
There's nothing uniquely awful about midnight on Tuesdays, it's just that there's only one data point for that particular time, and it's an outlier. Is it possible to have the graph show midnight as missing unless there are more than (for example) three different records from midnight being averaged together?
You could define an aggregate calculated field, called say avg_mood as:
if count(Mood) >= 3 then avg(Mood) end
Since the aggregation is hard coded into the calculation, Tableau will display AGG(avg_mood) for the field on any shelves you use it on, rather than letting you toggle the aggregation outside the formula as it will for other measures.
Note, there is no else branch, so the calculation will evaluate to null if there are less than three non-null Moods in a partition of data rows (based on the dimensions)
You can control how null values are displayed in a line chart. On the format pane, select the field in question from the pull down menu by the word Fields at the top right of the format pane, then select the Pane tab, then at the bottom of the format pane, adjust the Mark settings in the Special value section.
I want to aggregate bins in tableau.
See the following figure:
I want to aggregate (merge) the NumberM from 6 untill 16 in one category. 5+/(6 and higher) for example and sum the values of 6-16 in that category. I think this can be done with a few simple clicks but I am not able to manage.
Thanks in advance,
Tim
There are several ways to classify data rows into different groups or classes: each with different strengths.
Create a calculated field As emh mentioned, one approach is to create a calculated field to assign a value to a new field indicating which group each data row belongs to. For the effect you want, the calculated field should be discrete (blue). If your calculation doesn't return a value for in one case, e.g. an if statement without an else clause, then the field will be null in that case which is a group in itself. This is a very general approach, and can handle much more complex cases. The only downsides are the need to maintain the calculated field definition and that the cutoff values are hard coded and by itself can't be changed dynamically via a control on the view. BUT those issues can by easily resolved by using a parameter instead of a numeric literal in your calculated field. In fact, that's probably the number one use case for parameters. If you think in SQL, a discrete field on a shelf is like a group by clause.
Use a filter If you only want a subset of the data in your view, e.g. data rows with NumberM in [6, 16] then you can drag the NumberM field onto the filters shelf and select the range you want. Note for continuous (green) numeric fields, filter ranges include their endpoints. Filters are very quick and easy to drop on a view. They can be made dynamically adjustable by right clicking on them and creating a quick filter. Its obvious from the view that a filter is in use, and the caption will include the filter settings in its description. But a filter doesn't let you define multiple bins. If you think in SQL, a filter is like a where clause (or in some cases using the condition tab, like a having clause)
Define histogram bins If you want to create regular sized bins to cover a numeric range, such as values in [1,5], [6,10], [11-15] ..., Tableau can create the bin field for you automatically. Just right click on a numeric field, and select Create Bins.
Define a group Very useful for aggregating discrete values, such as string fields, into categories. Good for rolling up detail or handling multiple spellings or variants in your data. Just right click on a field and select Create Group. Or select some discrete values on an axis or legend and press the paperclip option. If you then edit a group, you'll see what's going on. If you think in SQL, a group is like a SQL case statement.
Define a set Another way to roll up values. The definition of a set can be dynamically computed or a hard coded list of members. Both kinds are useful. You can combine sets with union, intersection, set difference operators, and can test set membership in calculated fields. Sets are useful for binary decisions, rows are divided into those that are members of the set and those that are not.
Filters, sets, groups, calculated fields and parameters can often be combined to accomplish different effects.
Most if not all of these features can be implemented using calculated fields, especially if the business rules get complicated. But if a filter, bin, group or set fits your problem well, then it's often best to start with that, rather than define a calculated field for each and every situation. That said, learning about the 4 kinds of calculated fields really makes a difference in being able to use Tableau well.
You can do this with calculated fields.
Go to: Select Analysis > Create Calculated Field.
Then use this formula:
IF NumberM > 5 THEN "OVER 5"
You can then use that calculated field as a filter on the worksheet in your screenshot.
Answering my own question:
With Tableau 9 this can be easily done with the increased flexibility of the level of detail expressions (LOD). I can really recommend this blog on that subject and many more Tableau functions.