CONTENTS
- DESCRIPTION
- SYNOPSIS
- EXAMPLES
- WORKBOOK METHOD
- WORKSHEET METHOD
- PAGE SET-UP METHOD
- CELL FORMATTING
- FORMAT METHODS
- COLORS IN EXCEL
- DATES AND TIME IN EXCEL
- OUTLINES AND GROUPING IN EXCEL
- DATA VALIDATION IN EXCEL
- CONDITIONAL FORMATTING IN EXCEL
- SPARKLINES IN EXCEL
- TABLES IN EXCEL
- FORMURAS AND FUNCTIONS IN EXCEL
- CHART METHODS
- CHART FONTS
- CHART LAYOUT
- SHAPE
- COMPATIBILITY WITH WRITEEXCEL
FORMULAS AND FUNCTIONS IN EXCEL
Introduction
The following is a brief introduction to formulas and functions in Excel and WriteXLSX.
A formula is a string that begins with an equals sign:
'=A1+B1'
'=AVERAGE(1, 2, 3)'
The formula can contain numbers, strings, boolean values, cell references, cell ranges and functions. Named ranges are not supported. Formulas should be written as they appear in Excel, that is cells and functions must be in uppercase.
Cells in Excel are referenced using the A1 notation system where the column is designated by a letter and the row by a number. Columns range from A to XFD i.e. 0 to 16384, rows range from 1 to 1048576.
The Excel $ notation in cell references is also supported.
This allows you to specify whether a row or column is relative or absolute.
This only has an effect if the cell is copied.
The following examples show relative and absolute values.
'=A1' # Column and row are relative
'=$A1' # Column is absolute and row is relative
'=A$1' # Column is relative and row is absolute
'=$A$1' # Column and row are absolute
Formulas can also refer to cells in other worksheets of the current workbook. For example:
'=Sheet2!A1'
'=Sheet2!A1:A5'
'=Sheet2:Sheet3!A1'
'=Sheet2:Sheet3!A1:A5'
%q{='Test Data'!A1}
%q{='Test Data1:Test Data2'!A1}
The sheet reference and the cell reference are separated by ! the exclamation
mark symbol.
If worksheet names contain spaces, commas or parentheses then Excel requires
that the name is enclosed in single quotes as shown in the last two examples above.
In order to avoid using a lot of escape characters you can use the quote operator %q{}
to protect the quotes.
Only valid sheet names that have been added using the add_worksheet() method
can be used in formulas.
You cannot reference external workbooks.
The following table lists the operators that are available in Excel’s formulas. The majority of the operators are the same as Ruby’s, differences are indicated:
Arithmetic operators:
=====================
Operator Meaning Example
+ Addition 1+2
- Subtraction 2-1
* Multiplication 2*3
/ Division 1/4
^ Exponentiation 2^3 # Equivalent to **
- Unary minus -(1+2)
% Percent (Not modulus) 13%
Comparison operators:
=====================
Operator Meaning Example
= Equal to A1 = B1 # Equivalent to ==
<> Not equal to A1 <> B1 # Equivalent to !=
> Greater than A1 > B1
< Less than A1 < B1
>= Greater than or equal to A1 >= B1
<= Less than or equal to A1 <= B1
String operator:
================
Operator Meaning Example
& Concatenation "Hello " & "World!" # [1]
Reference operators:
====================
Operator Meaning Example
: Range operator A1:A4 # [2]
, Union operator SUM(1, 2+2, B3)
Notes:
[1]: Equivalent to "Hello " + "World!" in Ruby.
[2]: This range is equivalent to cells A1, A2, A3 and A4.
The range and comma operators can have different symbols in non-English versions of Excel, see below.
For a general introduction to Excel’s formulas and an explanation of the syntax of the function refer to the Excel help files or the following: http://office.microsoft.com/en-us/assistance/CH062528031033.aspx.
In most cases a formula in Excel can be used directly in the write_formula method. However, there are a few potential issues and differences that the user should be aware of. These are explained in the following sections.
Non US Excel functions and syntax
Excel stores formulas in the format of the US English version, regardless of the language or locale of the end-user’s version of Excel. Therefore all formula function names written using WriteXLSX must be in English.
worksheet.write_formula('A1', '=SUM(1, 2, 3)') # OK
worksheet.write_formula('A2', '=SOMME(1, 2, 3)') # French, Error on load.
Also, formulas must be written with the US Style separator/range operator which is a comma (not semi-colon). Therefore a formula with multiple values should be written as follows:
worksheet.write_formula('A1', '=SUM(1, 2, 3)') # OK
worksheet.write_formula('A2', '=SUM(1; 2; 3)') # Semi-colon. Error on load.
If you have a non-English version of Excel you can use the following multi-lingual Formula Translator (https://en.excel-translator.de/language/) to help you convert the formula. It can also replace semi-colon with commas.
Formulas added in Excel 2010 and later
Excel 2010 and later added functions which weren’t defined in the original file specification. These functions are reffered to by Microsoft as future functions. Examples of these functions are ACOT, CHISQ.DIST.RT, CONFIDENCE.NORM, STDEV.P, STDEV.S and WORKDAY.INTL.
When written using write_formula() these functions need to be fully qualified with a _xlfn. (or other) prefix as they are shown the list below. For example:
worksheet.write_formula('A1', '=_xlfn.STDEV.S(B1:B10)')
They will appear without the prefix in Excel.
The following list is taken from MS XLSX extensions documentation on future functions: https://msdn.microsoft.com/en-us/library/dd907480%28v=office.12%29.aspx
_xlfn.ACOT
_xlfn.ACOTH
_xlfn.AGGREGATE
_xlfn.ARABIC
_xlfn.BASE
_xlfn.BETA.DIST
_xlfn.BETA.INV
_xlfn.BINOM.DIST
_xlfn.BINOM.DIST.RANGE
_xlfn.BINOM.INV
_xlfn.BITAND
_xlfn.BITLSHIFT
_xlfn.BITOR
_xlfn.BITRSHIFT
_xlfn.BITXOR
_xlfn.CEILING.MATH
_xlfn.CEILING.PRECISE
_xlfn.CHISQ.DIST
_xlfn.CHISQ.DIST.RT
_xlfn.CHISQ.INV
_xlfn.CHISQ.INV.RT
_xlfn.CHISQ.TEST
_xlfn.COMBINA
_xlfn.CONFIDENCE.NORM
_xlfn.CONFIDENCE.T
_xlfn.COT
_xlfn.COTH
_xlfn.COVARIANCE.P
_xlfn.COVARIANCE.S
_xlfn.CSC
_xlfn.CSCH
_xlfn.DAYS
_xlfn.DECIMAL
ECMA.CEILING
_xlfn.ERF.PRECISE
_xlfn.ERFC.PRECISE
_xlfn.EXPON.DIST
_xlfn.F.DIST
_xlfn.F.DIST.RT
_xlfn.F.INV
_xlfn.F.INV.RT
_xlfn.F.TEST
_xlfn.FILTERXML
_xlfn.FLOOR.MATH
_xlfn.FLOOR.PRECISE
_xlfn.FORECAST.ETS
_xlfn.FORECAST.ETS.CONFINT
_xlfn.FORECAST.ETS.SEASONALITY
_xlfn.FORECAST.ETS.STAT
_xlfn.FORECAST.LINEAR
_xlfn.FORMULATEXT
_xlfn.GAMMA
_xlfn.GAMMA.DIST
_xlfn.GAMMA.INV
_xlfn.GAMMALN.PRECISE
_xlfn.GAUSS
_xlfn.HYPGEOM.DIST
_xlfn.IFNA
_xlfn.IMCOSH
_xlfn.IMCOT
_xlfn.IMCSC
_xlfn.IMCSCH
_xlfn.IMSEC
_xlfn.IMSECH
_xlfn.IMSINH
_xlfn.IMTAN
_xlfn.ISFORMULA
ISO.CEILING
_xlfn.ISOWEEKNUM
_xlfn.LOGNORM.DIST
_xlfn.LOGNORM.INV
_xlfn.MODE.MULT
_xlfn.MODE.SNGL
_xlfn.MUNIT
_xlfn.NEGBINOM.DIST
NETWORKDAYS.INTL
_xlfn.NORM.DIST
_xlfn.NORM.INV
_xlfn.NORM.S.DIST
_xlfn.NORM.S.INV
_xlfn.NUMBERVALUE
_xlfn.PDURATION
_xlfn.PERCENTILE.EXC
_xlfn.PERCENTILE.INC
_xlfn.PERCENTRANK.EXC
_xlfn.PERCENTRANK.INC
_xlfn.PERMUTATIONA
_xlfn.PHI
_xlfn.POISSON.DIST
_xlfn.QUARTILE.EXC
_xlfn.QUARTILE.INC
_xlfn.QUERYSTRING
_xlfn.RANK.AVG
_xlfn.RANK.EQ
_xlfn.RRI
_xlfn.SEC
_xlfn.SECH
_xlfn.SHEET
_xlfn.SHEETS
_xlfn.SKEW.P
_xlfn.STDEV.P
_xlfn.STDEV.S
_xlfn.T.DIST
_xlfn.T.DIST.2T
_xlfn.T.DIST.RT
_xlfn.T.INV
_xlfn.T.INV.2T
_xlfn.T.TEST
_xlfn.UNICHAR
_xlfn.UNICODE
_xlfn.VAR.P
_xlfn.VAR.S
_xlfn.WEBSERVICE
_xlfn.WEIBULL.DIST
WORKDAY.INTL
_xlfn.XOR
_xlfn.Z.TEST
Using Tables in Formulas
Worksheet tables can be aded with WriteXLSX using the add_table method.
worksheet.add_table('B3:F7', {options})
By default tables are named Table1, Table2, etc., in the order that they are added. However it can also be set by the user using the name parameter:
worksheet.add_table('B3:F7', {name: 'SalesData'})
If you need to know the name of the table, for example to use it in a formula, you can get it as follows:
table = worksheet.add_table('B3:F7')
table_name = table.name
When used in a formula a table name such as TableX should be reffered to as TableX[]:
worksheet.write_formula('A5', 'VLOOKUP("Sales", Table1[], 2, FALSE'))
Dealing with #NAME? errors
If there is an error in the syntax of a formula it is usually displayed in Excel as #NAME?. If you encounter an error like this you can debug it as follows:
- Ensure the formula is valild in Excel by copying and pasting it into a cell. Note, this should be done in Excel and not other applications such as OpenOffice or LibreOffice since they may have slightly difference syntax.
- Ensure the formula is using comma separators instead of semi-colon, see
"Non US Excel functions and syntax"above. - Ensure the formula is in English, see
"Non US Excel functions and syntax"above. - Ensure that the formula doesn’t contain an Excel 2010+ future function as listed in
"Formulas added in Excel 2010 and later"above. If it does then ensure that the correct prefix is used.
Finally if you have completed all the previous steps and still get a #NAME? error you can examine a valid Excel file to see what the correct syntax should be. To do this you should create a valid formula in Excel and save the file. You can then examine the XML in the unzipped file.
The following shows how to do that using Linux unzip and libxml’s xmllint http://xmlsoft.org/xmllint.html to format the XML for clarity:
$ unzipo myfile.xlsx -d myfile
$ xmllint --format myfile/xl/worksheets/sheet1.xml | grep '<f>'
<f>SUM(1, 2, 3)</f>
Formula Results
WriteXLSX doesn’t calculate the result of a formula and instead stores the value 0 as the fomula result. It then sets a global flag in the XLSX file to say that all formulas and functions should recalculated when the file is opened.
This is the method recommended in the Excel documentation and in general it works fine with spreadsheet applications. However, applications that don’t have a facility to calculate formulas will only display the 0 results. Examples of such applications are Excel Viewer, PDF Converters, and some mobile device applications.
If required, it is also possible to specify the calculated result of the formula using the optional last value parameter in write_formula:
worksheet.write_formula('A1', '=2+2', num_format, 4)
The value parameter can be a number, a string, a boolean string ('TRUE' or 'FALSE') or one of the following Excel error codes:
#DIV/0!
#N/A
#NAME?
#NULL!
#NUM!
#REF!
#VALUE!
It is also possible to specify the calculated result of an array formula created with write_array_formula:
# Specify the result for a single cell range.
Worksheet.write_array_formula('A1:A1', '{=SUM(B1:C1*B2:C2)}', format, 2005)
However, using this parameter only writes a single value to the upper left cel in the result array.
For a multi-cell array formula where the results are required, the other result values can be specified by using write_number to write to the appropriate cell:
#Specify the results for a multi cell range.
worksheet.write_array_formula('A1:A3', '{=TREND(C1:C3,B1:B3)}', format, 15)
worksheet.write_number('A2', 12, format)
worksheet.write_number('A3', 14, format)