Identify the incorrect statement from the following for aggregate function
Additional InformationHow to determine if a field is aggregated. Imported fields from the underlying data and Level of Detail (LOD) expressions are always non-aggregated until they are wrapped in an aggregation, such as SUM(), MIN(), ATTR(). To see a full list of all aggregated functions, please look at the "Aggregate Functions" article in the related links section.Calculated fields can be either aggregate or non-aggregate depending on how aggregations are used. If no aggregations are used, or if the outer most expression is a LOD expression, then the calculation will return non-aggregated results. One trick to determine if a field is aggregated is to add the field into the view. If the field displays AGG("Field Name"), the field is already aggregated Examples:Below is an explanation of how each option works using the sample data set shown as a reference. Sample Data SetRow IDProfitSales110030250603710 Option 1
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Option 2[Profit] / [Sales]Result: (assuming that the aggregation in the view is SUM) 100/30 + 50/60 + 7/10 = 3.333 + .833 + .7 = 4.867 Option 3Result:30 + 0 + 0 = 30 Option 4
[Sales]/{FIXED: SUM( [Sales] )} Result: (assuming that the aggregation is sum) 30/100 + 60/100 + 10/100 = 3+60+10 = .3 + .6 + .1 = 1 Discuss this article... Feedback Forum Did this article resolve the issue? Thank you for providing your feedback on the effectiveness of the article. Click here to return to our Support page. Open new Case Open a new case Continue Searching Click here to go to our Support page. Knowledge Base Get detailed answers and how-to step-by-step instructions for your issues and technical questions. Community Find and share solutions with our active community through forums, user groups and ideas. Product Help Browse a complete list of product manuals and guides. Available online, offline and PDF formats. Training and Tutorials Learn how to master Tableau’s products with our on-demand, live or class room training. This article introduces aggregate functions and their uses in Tableau. It also demonstrates how to create an aggregate calculation using an example. Why use aggregate functionsAggregate functions allow you to summarize or change the granularity of your data. For example, you might want to know exactly how many orders your store had for a particular year. You can use the COUNTD function to summarize the exact number of orders your company had, and then break the visualization down by year. The calculation might look something like this:
The visualization might look something like this: Aggregate functions available in TableauAggregations and floating-point arithmetic: The results of some aggregations may not always be exactly as expected. For example, you may find that the Sum function returns a value such as -1.42e-14 for a column of numbers that you know should sum to exactly 0. This happens because the Institute of Electrical and Electronics Engineers (IEEE) 754 floating-point standard requires that numbers be stored in binary format, which means that numbers are sometimes rounded at extremely fine levels of precision. You can eliminate this potential distraction by using the ROUND function (see Number Functions) or by formatting the number to show fewer decimal places. FunctionSyntaxDefinitionATTR
Returns the value of the expression if it has a single value for all rows. Otherwise returns an asterisk. Null values are ignored. AVG
Returns the average of all the values in the expression. AVG can be used with numeric fields only. Null values are ignored. COLLECT
An aggregate calculation that combines the values in the argument field. Null values are ignored. Note: The COLLECT function can only be used with spatial fields. Example:
CORR
Returns the Pearson correlation coefficient of two expressions. The Pearson correlation measures the linear relationship between two variables. Results range from -1 to +1 inclusive, where 1 denotes an exact positive linear relationship, as when a positive change in one variable implies a positive change of corresponding magnitude in the other, 0 denotes no linear relationship between the variance, and −1 is an exact negative relationship. CORR is available with the following data sources:
For other data sources, consider either extracting the data or using WINDOW_CORR. See Table Calculation Functions. Note: The square of a CORR result is equivalent to the R-Squared value for a linear trend line model. See . Example: You can use CORR to visualize correlation in a disaggregated scatter plot. The way to do this is to use a table-scoped level of detail expression. For example:
With a level of detail expression, the correlation is run over all rows. If you used a formula like See COUNT
Returns the number of items in a group. Null values are not counted. COUNTD
COVAR
Returns the sample covariance of two expressions. Covariance quantifies how two variables change together. A positive covariance indicates that the variables tend to move in the same direction, as when larger values of one variable tend to correspond to larger values of the other variable, on average. Sample covariance uses the number of non-null data points n - 1 to normalize the covariance calculation, rather than n, which is used by the population covariance (available with the COVARP function). Sample covariance is the appropriate choice when the data is a random sample that is being used to estimate the covariance for a larger population. COVAR is available with the following data sources:
For other data sources, consider either extracting the data or using WINDOW_COVAR. See Table Calculation Functions. If expression1 and expression2 are the same—for example, COVAR([profit], [profit])—COVAR returns a value that indicates how widely values are distributed. Note: The value of COVAR(X, X) is equivalent to the value of VAR(X) and also to the value of STDEV(X)^2. Example: The following formula returns the sample covariance of Sales and Profit.
COVARP
Returns the population covariance of two expressions. Covariance quantifies how two variables change together. A positive covariance indicates that the variables tend to move in the same direction, as when larger values of one variable tend to correspond to larger values of the other variable, on average. Population covariance is sample covariance multiplied by (n-1)/n, where n is the total number of non-null data points. Population covariance is the appropriate choice when there is data available for all items of interest as opposed to when there is only a random subset of items, in which case sample covariance (with the COVAR function) is appropriate. COVARP is available with the following data sources:
For other data sources, consider either extracting the data or using WINDOW_COVARP. See Table Calculation Functions. If expression1 and expression2 are the same—for example, COVARP([profit], [profit])—COVARP returns a value that indicates how widely values are distributed. Note: The value of COVARP(X, X) is equivalent to the value of VARP(X) and also to the value of STDEVP(X)^2. Example: The following formula returns the population covariance of Sales and Profit.
MAX
Returns the maximum of an expression across all records. If the expression is a string value, this function returns the last value where last is defined by alphabetical order. MEDIAN
Returns the median of an expression across all records. Median can only be used with numeric fields. Null values are ignored. This function is not available for workbooks created before Tableau Desktop 8.2 or that use legacy connections. It is also not available for connections using any of the following data sources:
For other data source types, you can extract your data into an extract file to use this function. See Extract Your Data. MIN
Returns the minimum of an expression across all records. If the expression is a string value, this function returns the first value where first is defined by alphabetical order. PERCENTILE
Returns the percentile value from the given expression corresponding to the specified number. The number must be between 0 and 1 (inclusive)—for example, 0.66, and must be a numeric constant. This function is available for the following data sources.
For other data source types, you can extract your data into an extract file to use this function. See Extract Your Data. STDEV
Returns the statistical standard deviation of all values in the given expression based on a sample of the population. STDEVP
Returns the statistical standard deviation of all values in the given expression based on a biased population. SUM
Returns the sum of all values in the expression. SUM can be used with numeric fields only. Null values are ignored. VAR
Returns the statistical variance of all values in the given expression based on a sample of the population. VARP
Returns the statistical variance of all values in the given expression on the entire population. Create an aggregate calculationFollow along with the steps below to learn how to create an aggregate calculation.
Rules for aggregate calculationsThe rules that apply to aggregate calculations are as follows:
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