How to use the DVARP function

What is the DVARP function?

The DVARP function returns the variance of an entire population based on given condition or criteria in a list or database.

1. Introduction

Does the DVARP function ignore error values?

No, it doesn't ignore error values.

What is DVARP an abbreviation of?

DVARP is an abbreviation of Database Variance Population.

What is variance?

Variance is a metric used in statistics, it shows how much a set of numbers are spread out from their average value, see below example.

Both Set1 and Set2 above have the same average 30, however, values in Set2 are much more spread out.

Set1 variance: 170 and Set2 variance: 8600.

What is variance based on a population vs variance based on a sample?

The main difference between population variance and sample variance is that the population variance is calculated from an entire population of data:
σ² = Σ (x - μ)² / N
N is the total number of data points in the population.
μ is the true population mean.

Whereas the sample variance is calculated from a sample drawn from a population
s² = Σ(x - x̅)² / (n - 1)
n is the number of data points in the sample.
x̅ is the sample mean.

What is the mean?

The arithmetic mean is the average in other words.

The average is a way to calculate central tendency which is the place of the center of a set of numbers in a statistical distribution. The most often used measures to calculate central tendency are:

• Average - arithmetic mean.
• Median - the middle number of a group of numbers.
• Mode - the most frequent item in a group

However, the arithmetic mean is used in the DVARP function.

What is arithmetic mean?

The arithmetic mean is calculated by dividing the sum of all values by the number of values.

For example, an array contains these numbers: 3,2,1

The sum is 3 + 2 + 1 equals 6
The number of values is 3.
6/3 equals 2. The average of 3, 2, 1 is 2

What is a database in this context?

Excel defines a database as a list of related data in which rows of related information are records, and columns of data are fields. The first row of the list contains labels for each column.

Why use the DVARP function?

The DVARP function calculates the variance based on cells that match a condition or criteria in a list/database whereas the VAR.P function calculates variance without a condition/criteria.

Where can you place the criteria range?

You can place your criteria range wherever you want on your worksheet, however, it is not recommended below the list/database. The function needs a blank row below the list to work properly.

What criteria characters are allowed?

Allowed criteria range characters are less than and greater than signs <>, use them to specify a criteria range. Also, asterisks * can be used to match partial strings.

How to calculate the Variance for the entire list/database?

To include the entire list/database enter a blank line below the criteria range column labels.

2. Syntax

DVARP(database, field, criteria)

database	Required.  The cell reference to a list or database.
field	Required. The field argument lets you choose which column to use. You can use the column name enclosed with double quotation marks or the corresponding column number.
criteria	Required.  A cell reference to the criteria range. The criteria range needs to have column labels and at least one condition below the column label.

3. Example

What is the variance of the "Number" values for items with a "Size" of "L" in the given data set?

This demonstrates an Excel function that calculates the variance of a specific column (field) within a data range based on provided criteria. The formula in cell G15 is:

Arguments:

1. B18:D26 - This is a range reference that contains the data for the calculation. It includes the Item, Size, and Number columns from rows 18 to 26.
2. 3 - This is a constant value that specifies the data field for which the variance is to be calculated. In this case, 3 refers to the third column (Number) within the data range.
3. B15:D16 - This is another range reference that contains the criteria for the calculation. In this case, it includes the value "L" in cell B16 which is the criteria for the Size column.

The data in the referenced ranges:
- B18:D26 contains a list of items with their sizes and associated numbers.

Item	Size	Number
A102	M	370
A103	L	690
A099	S	310
A412	S	190
A341	L	550
A340	M	730
A202	L	623

- B15:D16 contains the criteria "L" in cell B16, which is the criteria for the Size column.

Item	Size	Number
	L

The DVARP function calculates the variance of the Number values for those rows where the Size value matches the criteria "L".

The result 3268.67 is derived by calculating the variance of the numbers for items with size "L" in the data range. These items are A103, A341, and A202, with numbers 690, 550, and 623, respectively.

The image displays a graph showing the probability density function (PDF) of a normal distribution with a mean around 621 and a standard deviation around 57. The calculated variance (σ^2) of 3268.67, and the square root of the variance (σ) of 57.17, which is the standard deviation.

Follow these steps to calculate the variance from a population using the formula Σ(x - x̄)^2/n based on these observations 690, 550, and 623:

1. Find the mean (x̄) of the observations:
   x̄ = (690 + 550 + 623) / 3
   x̄ = 1863 / 3
   x̄ = 621
2. Calculate the deviation of each observation from the mean (x - x̄):
   690 - 621 = 69
   550 - 621 = -71
   623 - 621 = 2
3. Square each deviation:
   69^2 = 4761
   (-71)^2 = 5041
   2^2 = 4
4. Sum the squared deviations:
   4761 + 5041 + 4 = 9806
5. Divide the sum of squared deviations by n, where n is the total number of observations:
   9806 / 3 = 3268.67

The variance of the population observations 690, 550, and 623 is 3268.67 which matches the result shown in the image.

Σ(x - x̄)^2/n

Σ represents the summation of the squared deviations
x is each individual observation
x̄ is the mean of the observations
n is the total number of observations

This formula calculates the average squared deviation from the mean for the entire population, giving the variance.

4. Function not working

The DVARP function returns a

• #VALUE! error if the field argument is out of range.
• propagates errors in the source data.

4.1 Troubleshooting the error value

When you encounter an error value in a cell a warning symbol appears, displayed in the image above. Press with mouse on it to see a pop-up menu that lets you get more information about the error.

1. The first line describes the error if you press with left mouse button on it.
2. The second line opens a pane that explains the error in greater detail.
3. The third line takes you to the "Evaluate Formula" tool, a dialog box appears allowing you to examine the formula in greater detail.
4. This line lets you ignore the error value meaning the warning icon disappears, however, the error is still in the cell.
5. The fifth line lets you edit the formula in the Formula bar.
6. The sixth line opens the Excel settings so you can adjust the Error Checking Options.

Here are a few of the most common Excel errors you may encounter.

#NULL error - This error occurs most often if you by mistake use a space character in a formula where it shouldn't be. Excel interprets a space character as an intersection operator. If the ranges don't intersect an #NULL error is returned. The #NULL! error occurs when a formula attempts to calculate the intersection of two ranges that do not actually intersect. This can happen when the wrong range operator is used in the formula, or when the intersection operator (represented by a space character) is used between two ranges that do not overlap. To fix this error double check that the ranges referenced in the formula that use the intersection operator actually have cells in common.

#SPILL error - The #SPILL! error occurs only in version Excel 365 and is caused by a dynamic array being to large, meaning there are cells below and/or to the right that are not empty. This prevents the dynamic array formula expanding into new empty cells.

#DIV/0 error - This error happens if you try to divide a number by 0 (zero) or a value that equates to zero which is not possible mathematically.

#VALUE error - The #VALUE error occurs when a formula has a value that is of the wrong data type. Such as text where a number is expected or when dates are evaluated as text.

#REF error - The #REF error happens when a cell reference is invalid. This can happen if a cell is deleted that is referenced by a formula.

#NAME error - The #NAME error happens if you misspelled a function or a named range.

#NUM error - The #NUM error shows up when you try to use invalid numeric values in formulas, like square root of a negative number.

#N/A error - The #N/A error happens when a value is not available for a formula or found in a given cell range, for example in the VLOOKUP or MATCH functions.

#GETTING_DATA error - The #GETTING_DATA error shows while external sources are loading, this can indicate a delay in fetching the data or that the external source is unavailable right now.

4.2 The formula returns an unexpected value

To understand why a formula returns an unexpected value we need to examine the calculations steps in detail. Luckily, Excel has a tool that is really handy in these situations. Here is how to troubleshoot a formula:

1. Select the cell containing the formula you want to examine in detail.
2. Go to tab “Formulas” on the ribbon.
3. Press with left mouse button on "Evaluate Formula" button. A dialog box appears.
   The formula appears in a white field inside the dialog box. Underlined expressions are calculations being processed in the next step. The italicized expression is the most recent result. The buttons at the bottom of the dialog box allows you to evaluate the formula in smaller calculations which you control.
4. Press with left mouse button on the "Evaluate" button located at the bottom of the dialog box to process the underlined expression.
5. Repeat pressing the "Evaluate" button until you have seen all calculations step by step. This allows you to examine the formula in greater detail and hopefully find the culprit.
6. Press "Close" button to dismiss the dialog box.

There is also another way to debug formulas using the function key F9. F9 is especially useful if you have a feeling that a specific part of the formula is the issue, this makes it faster than the "Evaluate Formula" tool since you don't need to go through all calculations to find the issue..

1. Enter Edit mode: Double-press with left mouse button on the cell or press F2 to enter Edit mode for the formula.
2. Select part of the formula: Highlight the specific part of the formula you want to evaluate. You can select and evaluate any part of the formula that could work as a standalone formula.
3. Press F9: This will calculate and display the result of just that selected portion.
4. Evaluate step-by-step: You can select and evaluate different parts of the formula to see intermediate results.
5. Check for errors: This allows you to pinpoint which part of a complex formula may be causing an error.

The image above shows cell reference B18:D25 converted to hard-coded value using the F9 key. The DVARP function requires non-error values which is not the case in this example. We have found what is wrong with the formula.

Tips!

• View actual values: Selecting a cell reference and pressing F9 will show the actual values in those cells.
• Exit safely: Press Esc to exit Edit mode without changing the formula. Don't press Enter, as that would replace the formula part with the calculated value.
• Full recalculation: Pressing F9 outside of Edit mode will recalculate all formulas in the workbook.

Remember to be careful not to accidentally overwrite parts of your formula when using F9. Always exit with Esc rather than Enter to preserve the original formula. However, if you make a mistake overwriting the formula it is not the end of the world. You can “undo” the action by pressing keyboard shortcut keys CTRL + z or pressing the “Undo” button

4.3 Other errors

Floating-point arithmetic may give inaccurate results in Excel - Article

Floating-point errors are usually very small, often beyond the 15th decimal place, and in most cases don't affect calculations significantly.

Functions in 'Database' category

The DVARP function function is one of 11 functions in the 'Database' category.

Excel function categories

Excel categories

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