* First steps toward refactoring Statistical Distributions into smaller classes: BETA() and GAMMA() (and related functions) to start with... they all need a lot of tidying up, and more testing; but it's a start
* Add basic datatype validations to Beta and Gamma Excel function implementations
* Switch to using a trait with the validation methods to provide easier sharing between distribution classes
* Additional unit tests for Beta and Gamma functions, including unhappy path for validations
* Extract ChiSquared functions
* Additional argument validation checks with unit tests for Chi Squared functions
* Extract Fisher
* Move MEDIAN() and MODE() to the Averages class
* Extract filters for Median and Mode for common usage
* Problems Using Builtin PHP Functions Directly As Excel Functions
This fixes issue #1789.
As originally reported, stricter typing was causing PHP8 to throw
an exception when a non-numeric value was passed to the Round function.
Previous releases of PHP did not see this problem, however, on further
analysis, they were also incorrect in returning 0 as the result in the
erroneous situation, when they should have been returning a VALUE error.
Yet more analysis showed that other functions would also have problems,
and, in addition, might not handle invalid input (e.g. a negative length
passed to REPT) or output (e.g. NAN in the case of ACOS(2)) correctly.
The following MathTrig functions are affected:
ABS, ACOS, ACOSH, ASIN, ASINH, ATAN, ATANH,
COS, COSH, DEGREES (rad2deg), EXP, LN (log), LOG10,
RADIANS (deg2rad), REPT (str_repeat), SIN, SINH, SQRT, TAN, TANH.
One TextData function (REPT) is also affected.
This change lets PhpSpreadsheet validate the input for each of these
functions before passing control to the builtin, and handle the output
afterwards.
There were no explicit tests for any of these functions, a fact made
easy to ignore by the fact that PhpSpreadsheet delegated the heavy
lifting to PHP itself for these cases. A full suite of tests is
now added for each of the affected functions.
* Scrutinizer Recommendations
Only in 3 modules which are part of this PR.
* Improved Handling of Tan(PI/2)
Return DIV0 error for TAN when COS is very small.
* Additional Trig Tests
Results which should be infinity, i.e. DIV/0 error.
This had been intended to get 100% coverage for TextData functions, and it does that.
However, some minor bugs requiring source changes arose during testing.
- the Excel CHAR function restricts its argument to 1-255. PhpSpreadsheet CHARACTER
had been allowing 0+. Also, there is no need to test if iconv exists,
since it is part of Composer requirements.
- The DOLLAR function had been returning NUM for invalid arguments. Excel returns VALUE.
Also, negative amounts were not being handled correctly.
- The FIXEDFORMAT function had been returning NUM for invalid arguments. Excel FIXED returns VALUE.
- Fix ISFORMULA() function to work with a cell reference to another worksheet
- Added calculation engine support for the new functions that were added in MS Excel 2013 and MS Excel 2016
- Text Functions
- CONCAT() Synonym for CONCATENATE()
- NUMBERVALUE() Converts text to a number, in a locale-independent way
- UNICHAR() Synonym for CHAR() in PHPSpreadsheet, which has always used UTF-8 internally
- UNIORD() Synonym for ORD() in PHPSpreadsheet, which has always used UTF-8 internally
- TEXTJOIN() Joins together two or more text strings, separated by a delimiter
- Logical Functions
- XOR() Returns a logical Exclusive Or of all arguments
- Date/Time Functions
- ISOWEEKNUM() Returns the ISO 8601 week number of the year for a given date
- Lookup and Reference Functions
- FORMULATEXT() Returns a formula as a string
- Engineering Functions
- ERF.PRECISE() Returns the error function integrated between 0 and a supplied limit
- ERFC.PRECISE() Synonym for ERFC
- Math and Trig Functions
- SEC() Returns the secant of an angle
- SECH() Returns the hyperbolic secant of an angle
- CSC() Returns the cosecant of an angle
- CSCH() Returns the hyperbolic cosecant of an angle
- COT() Returns the cotangent of an angle
- COTH() Returns the hyperbolic cotangent of an angle
- ACOT() Returns the cotangent of an angle
- ACOTH() Returns the hyperbolic cotangent of an angle
- Financial Functions
- PDURATION() Calculates the number of periods required for an investment to reach a specified value
- RRI() Calculates the interest rate required for an investment to grow to a specified future value
By design, UTF-8 allows any byte-oriented substring searching algorithm,
since the sequence of bytes for a character cannot occur anywhere else
([source](https://en.wikipedia.org/wiki/UTF-8#Advantages_3)).
So `str_replace()` also works for UTF-8-encoded strings, assuming that
the input strings are valid UTF-8 strings. The previous implementation
of mbStrReplace() did nothing to detect invalid strings.
Also, `str_replace()` does not support [Unicode equivalence](https://en.wikipedia.org/wiki/Unicode_equivalence),
but nor do the other `mb_string` functions, and nor does `=SUBSTITUTE()` in Excel
(tested on Excel for Mac version 15.19.1, Excel 2016 for Windows and LibreOffice 5.1).
Closes#109
Mark Baker
oleibman
Adrien Crivelli
Rolands Usāns
Christian Schmidt