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.
Related
I have a form data wherein tableau I am using the below value to find out the choices for a multiple value question. The question is Could you please indicate one or two areas where we fell short.
the value can be explosives, vehicles, cement etc
I have individually accounted for each of the choices in the below calculated field:
int(contains(lower([Could you please indicate one / two of the following areas where we fell short of meeting your expectations?]),'factory'))
Similarly I have found out for other values:
The calculated fields are hasvehicle, hasfactory etc
But the problem is how can I visualize the same in the form of bars?
All I am able to do is this:
How can I visualise the same in the form of bars side by side?
When you have one measure on Rows, drag the second measure and drop it in the axis.
It will result with Measure Names on the Columns shelf and Measure Values on the rows shelf.
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.)
I have a bar plot with average values for some dimensions, let's say: weekdays. Now I want to put an average line on it - I use Analytics > Average Line. The line I get doesn't show the average for all data examples though, but the average counted from the aggregated values on the plot (avg from 7 values).
Can I get somehow the other one?
Put whatever your [Value] field is called on the Detail shelf. Then double click on it to edit it on the shelf
Change the expression to Total(Avg([Value])) where Value is the field you are displaying
Use this field for your average line, Read about Total() in the documentation. You may also need to edit the table calc addressing and partitioning characteristics to scope your total as desired (although the default settings often work) Read about Table Calcs in the on-line help for more info
I've got a bar chart with three months worth of data. Each column in the chart is one month's data showing the percentage of Rows that met a certain criterion for that month. In the first month, 100% of 2 rows meet the measure. In the second month, 24.2% of 641 rows meet the measure. In the 3rd month, 28.3% of 1004 rows meet the measure. My reference line which is supposed to show the average across the entire time-frame is showing 50.8%, the simple average (i.e. [100+24.2+28.3]/3) instead of the weighted average (i.e. [100*2+641*24.2+1004*28.3]/[2+641+1004]).
In the rows shelf, I have a measure called "% that meet the criterion", this is defined as SUM([Criterion])/SUM([NUMBER OF RECORDS])
The criterion measure is 1 for any record that qualifies and null for any that do not qualify.
If I go to Analysis >> Totals >> Show Row Grand Totals, a 4th bar is added, and that bar shows the correct weighted average of the other three bars (26.8%), but I really want this to be shown as a reference line instead of having an extra bar on the chart. (Adding the Grand Total bar also drops the reference line down to 44.8%, which is the simple average of the 4 bars now shown on the chart--I can't think of a less useful piece of information than that).
How can I add the weighted average as a reference line?
Instead of using 'Average' as your aggregation, try using 'Total' instead in the Edit Reference Line dialogue window.
I have to say it's a bit counter-intuitive, but this is what the Tableau online help has to say about it:
http://onlinehelp.tableau.com/current/pro/online/mac/en-us/reflines_addlines.html
Total - places a line at the aggregate of all the values in either the cell, pane, or the entire view. This option is particularly useful when computing a weighted average rather than an average of averages. It is also useful when working with a calculation with a custom aggregation. The total is computed using the underlying data and behaves the same as selecting one of the totals option the Analysis menu.
If you are using Tableau 9, you can make second calculated field using an LOD expression
{ SUM([Criterion]) / SUM([NUMBER OF RECORDS]) }
This will calculate the ratio for the entire data set after applying context and data source filters, without partitioning the data by any of the other dimensions in your view (such as month in your case)
If you place that new field on the detail shelf then you can use it to create a reference line.
There are other ways to generate a weighted average, but this is probably the simplest in your case.