Is there a way to calculate the average across a table based on only the value in the first column (School Name) when the first column is a string value? The current values in School Average are not correct due to the additional column values (Grade and Teacher) needed prior to the measures.
This is an ideal use case for LOD calculations. An LOD calculation allows you to specify the dimensions for a calculation as part of the calculation definition -- instead of (solely) by the Tableau shelves and cards.
To start, you can define a calculated field called,say, School_Avg as
{ fixed [School Name] : avg([Grade]) }
Assuming you have a field called Grade.
There is much more to learn about LOD calculations. See the on line help to learn more.
Related
I am working in Tableau and trying to create a formula that will return me the value of each customer that walks into a store by dividing Net Sales / Traffic. When I try to combine the two separate formulas, it gives me the following error: Cannot mix aggregate and non-aggregate arguments with this function. The two functions I created that I'm trying to divide are:
SOT = (SUM([Sales Net])-SUM([Sales Gcard Net]))/SUM([Traffic Perday]) and SOT Goal
When I look at it in Tableau, it's stating that SOT is an aggregate function. How do I work around this to be able to get
SOT / SOT Goal
Aggregate variables are values that are calculated in the view, and depend on the level of aggregation in Tableau. e.g. sum(Sales) will show different values in Tableau if it’s next to a Region dimension, or if it’s next to a Category dimension.
In order to avoid the errors you can use many solutions. My favorite is indeed LOD expressions. In your view, though I do not have required sample data and therefore, I cannot try my hands on different possibilities here, I suggest that this should work-
SOT = ({SUM([Sales Net])}-{SUM([Sales Gcard Net])})/{SUM([Traffic Perday])}
Do remember that this solution will over-ride your filters and if you are using filters you have to add all those to Context.
EDIT
While trying different possibilities remember these things...
{SUM([Sales])} will sum the sales over entire data and {} i.e. curly braces wrapped around the sum function will cause to return the value as non-aggregate. In other words, this will work as LOD and if you'll add this field to view, the sum of entire sales will be shown against each row.
{FIXED [DIMENSION NAME] : sum([Sales])} will sum sales separately for each Dimension value. Fixed statement (LOD) again returns the value as non-aggregate value. if you'll add this field to view, the sum of entire sales for that dimension will be shown against each dimension.
I am trying to find the difference between 2 columns in tableau. The catch though here is that each column is ranked based on a value. The difference i need is between these 2 ranked columns
The rank is computed using the table calculations rank function. Attaching the picture for more information
I am assuming "current" and "prior" are calculated fields.
Just create a new calculated field, here I'll call it "Result". In this field just minus your one from the other so:
[Current - Prior]
Then pull this new field into your measures values on your sheet.
I've a problem to calculate weighted standard deviation. Here's the formula I used:
sum([Weight]*(([Variable]-[Mean Score - Variable])^2))
/
SUM([Weight])
But there's a error pop up message "Cannot mix aggregrate and non-aggregrate"
I wonder what's wrong with my formula?
Thanks
I am assuming Variable and Weight are explicit fields in your dataset, while [Mean Score] is a calculated field you defined in Tableau.
[Mean Score] is an aggregate calculation; Variable is not. You can check this by dragging [Mean Score] to any shelf in Tableau, and note that it is show within the prefix AGG(). Note that you can't select the form of aggregation (SUM, MIN, AVG) to apply in that case, because the aggregation function is defined within that calculation.
You can't mix aggregate and record level calculations directly. Record level calculations are evaluated once for each individual data row. Aggregate calculations are evaluated once for each block of data rows.
The dimensions used in your worksheet determine which data rows are grouped together into blocks (partitioning the data). Analogous to the fields that follow the keyword GROUP BY in SQL select statement. As with SQL, the other fields referenced must be aggregated somehow such as via a SUM(), MIN(), MAX() or other call. Tableau calls those fields measures.
The most straightforward solution is to revise your definition of [Mean Score] to make it a Level Of Detail (LOD) calc instead of an aggregate calc.
That will allow you to essentially first compute the mean score separately, and then reference that result in your record level calculation. You will have to decide among 3 different ways for determining the dimensions for your LOD calc. See the online help for more info on LOD calcs.
For example, try replacing [Mean Score] with { include : [Mean Score] }
My requirement is to get the second max date available in report and filter the data set on this.
I tried something like this:
datediff('day',dt,max(dt))=1
Referred to this link
any help?
You're going to need Tableau 9.0 for this. Basically because any calculation you do on Tableau depends on the level of detail you have on the worksheet (the dimensions you put in there). So datediff('day',dt,max(dt))=1 won't work. First because you're mixing aggregated fields (max(dt)) with non-aggreagated (dt). Second, because the aggregation depends on the dimensions in the workfield.
But Tableau 9.0 has a new awesome feature, called Level of Detail calculations. It allows you to perform calculations in the level of detail you choose, depending not on the dimensions on the sheet. It is also calculated BEFORE any calculation on the worksheet (just after context filters).
Now to the answer. First I'll figure out what is the max(dt). Let's call it max_dt
{ FIXED : MAX(dt) }
This will calculated the maximum of dt in all your database
Now to get the second max, you can go like this:
{ FIXED : MAX(IF dt != max_dt
THEN dt
END)
}
This will calculated the maximum of dt, ignoring those who are equal to max_dt (that is the true max(dt)). Therefore, the second max.
Take a look on those LOD calculations. They were just released, I'm having tons of fun with them right now
If the view has date dimension
The easy way to do this,is to create a calculated Last()=1
then filter off the records that evaluate to TRUE
I have a column with dollar amounts, such as:
$1.00
$4.00
$100.00
and so on. These values are put into the column by calculating the % of another column. I want to get the sum of all the dollar amounts of that column. I cant use Sum(data) because its static data in the column. Is there a way to get the sum easily?
Thanks!
There are a couple of different ways to deal with this:
If it's the same percentage being applied to each row, sum the original column and apply the same percentage to that sum.
If the original source of the data is from a database, do the percent calculation in your Dataset's SQL query, then use the Sum function in your Tablix as usual.
If these don't apply, you'll need to give more detailed information about your problem.