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Enumerations | Functions
math.h File Reference
#include <sal/config.h>
#include <rtl/ustring.h>
#include <sal/saldllapi.h>
#include <sal/types.h>

Go to the source code of this file.

Enumerations

enum  rtl_math_StringFormat {
  rtl_math_StringFormat_E, rtl_math_StringFormat_F, rtl_math_StringFormat_G, rtl_math_StringFormat_Automatic,
  rtl_math_StringFormat_E1, rtl_math_StringFormat_E2, rtl_math_StringFormat_G1, rtl_math_StringFormat_G2
}
 Formatting modes for rtl_math_doubleToString and rtl_math_doubleToUString and rtl_math_doubleToUStringBuffer. More...
 
enum  rtl_math_ConversionStatus { rtl_math_ConversionStatus_Ok, rtl_math_ConversionStatus_OutOfRange }
 Status for rtl_math_stringToDouble and rtl_math_uStringToDouble. More...
 
enum  rtl_math_RoundingMode {
  rtl_math_RoundingMode_Corrected, rtl_math_RoundingMode_Down, rtl_math_RoundingMode_Up, rtl_math_RoundingMode_Floor,
  rtl_math_RoundingMode_Ceiling, rtl_math_RoundingMode_HalfDown, rtl_math_RoundingMode_HalfUp, rtl_math_RoundingMode_HalfEven
}
 Rounding modes for rtl_math_round. More...
 
enum  rtl_math_DecimalPlaces { rtl_math_DecimalPlaces_Max = 0x7ffffff, rtl_math_DecimalPlaces_DefaultSignificance = rtl_math_DecimalPlaces_Max }
 Special decimal places constants for rtl_math_doubleToString and rtl_math_doubleToUString and rtl_math_doubleToUStringBuffer. More...
 

Functions

SAL_DLLPUBLIC void rtl_math_doubleToString (rtl_String **pResult, sal_Int32 *pResultCapacity, sal_Int32 nResultOffset, double fValue, enum rtl_math_StringFormat eFormat, sal_Int32 nDecPlaces, sal_Char cDecSeparator, sal_Int32 const *pGroups, sal_Char cGroupSeparator, sal_Bool bEraseTrailingDecZeros) SAL_THROW_EXTERN_C()
 Conversions analogous to sprintf() using internal rounding. More...
 
SAL_DLLPUBLIC void rtl_math_doubleToUString (rtl_uString **pResult, sal_Int32 *pResultCapacity, sal_Int32 nResultOffset, double fValue, enum rtl_math_StringFormat eFormat, sal_Int32 nDecPlaces, sal_Unicode cDecSeparator, sal_Int32 const *pGroups, sal_Unicode cGroupSeparator, sal_Bool bEraseTrailingDecZeros) SAL_THROW_EXTERN_C()
 Conversions analogous to sprintf() using internal rounding. More...
 
SAL_DLLPUBLIC double rtl_math_stringToDouble (sal_Char const *pBegin, sal_Char const *pEnd, sal_Char cDecSeparator, sal_Char cGroupSeparator, enum rtl_math_ConversionStatus *pStatus, sal_Char const **pParsedEnd) SAL_THROW_EXTERN_C()
 Conversion analogous to strtod(), convert a string representing a decimal number into a double value. More...
 
SAL_DLLPUBLIC double rtl_math_uStringToDouble (sal_Unicode const *pBegin, sal_Unicode const *pEnd, sal_Unicode cDecSeparator, sal_Unicode cGroupSeparator, enum rtl_math_ConversionStatus *pStatus, sal_Unicode const **pParsedEnd) SAL_THROW_EXTERN_C()
 Conversion analogous to strtod(), convert a string representing a decimal number into a double value. More...
 
SAL_DLLPUBLIC double rtl_math_round (double fValue, int nDecPlaces, enum rtl_math_RoundingMode eMode) SAL_THROW_EXTERN_C()
 Rounds a double value. More...
 
SAL_DLLPUBLIC double rtl_math_pow10Exp (double fValue, int nExp) SAL_THROW_EXTERN_C()
 Scales fVal to a power of 10 without calling pow() or div() for nExp values between -16 and +16, providing a faster method. More...
 
SAL_DLLPUBLIC double rtl_math_approxValue (double fValue) SAL_THROW_EXTERN_C()
 Rounds value to 15 significant decimal digits. More...
 
SAL_DLLPUBLIC bool rtl_math_approxEqual (double a, double b) SAL_THROW_EXTERN_C()
 Test equality of two values with an accuracy of the magnitude of the given values scaled by 2^-48 (4 bits roundoff stripped). More...
 
SAL_DLLPUBLIC double rtl_math_expm1 (double fValue) SAL_THROW_EXTERN_C()
 Returns more accurate e^x-1 for x near 0 than calculating directly. More...
 
SAL_DLLPUBLIC double rtl_math_log1p (double fValue) SAL_THROW_EXTERN_C()
 Returns more accurate log(1+x) for x near 0 than calculating directly. More...
 
SAL_DLLPUBLIC double rtl_math_atanh (double fValue) SAL_THROW_EXTERN_C()
 Returns more accurate atanh(x) for x near 0 than calculating 0.5*log((1+x)/(1-x)). More...
 
SAL_DLLPUBLIC double rtl_math_erf (double fValue) SAL_THROW_EXTERN_C()
 Returns values of the Errorfunction erf. More...
 
SAL_DLLPUBLIC double rtl_math_erfc (double fValue) SAL_THROW_EXTERN_C()
 Returns values of the complement Errorfunction erfc. More...
 
SAL_DLLPUBLIC double rtl_math_asinh (double fValue) SAL_THROW_EXTERN_C()
 Returns values of the inverse hyperbolic sine. More...
 
SAL_DLLPUBLIC double rtl_math_acosh (double fValue) SAL_THROW_EXTERN_C()
 Returns values of the inverse hyperbolic cosine. More...
 

Enumeration Type Documentation

Status for rtl_math_stringToDouble and rtl_math_uStringToDouble.

Enumerator
rtl_math_ConversionStatus_Ok 

Conversion was successful.

rtl_math_ConversionStatus_OutOfRange 

Conversion caused overflow or underflow.

Special decimal places constants for rtl_math_doubleToString and rtl_math_doubleToUString and rtl_math_doubleToUStringBuffer.

Enumerator
rtl_math_DecimalPlaces_Max 

Value to be used with rtl_math_StringFormat_Automatic.

rtl_math_DecimalPlaces_DefaultSignificance 

Value to be used with rtl_math_StringFormat_G.

In fact the same value as rtl_math_DecimalPlaces_Max, just an alias for better understanding.

Rounding modes for rtl_math_round.

Enumerator
rtl_math_RoundingMode_Corrected 

Like HalfUp, but corrects roundoff errors, preferred.

rtl_math_RoundingMode_Down 

Floor of absolute value, signed return (commercial).

rtl_math_RoundingMode_Up 

Ceil of absolute value, signed return (commercial).

rtl_math_RoundingMode_Floor 

Floor of signed value.

rtl_math_RoundingMode_Ceiling 

Ceil of signed value.

rtl_math_RoundingMode_HalfDown 

Frac <= 0.5 ? floor of abs : ceil of abs, signed return.

rtl_math_RoundingMode_HalfUp 

Frac < 0.5 ? floor of abs : ceil of abs, signed return (mathematical).

rtl_math_RoundingMode_HalfEven 

IEEE rounding mode (statistical).

Formatting modes for rtl_math_doubleToString and rtl_math_doubleToUString and rtl_math_doubleToUStringBuffer.

Enumerator
rtl_math_StringFormat_E 

Like sprintf() E.

rtl_math_StringFormat_F 

Like sprintf() f.

rtl_math_StringFormat_G 

Like sprintf() G, 'F' or 'E' format is used depending on which one is more compact.

rtl_math_StringFormat_Automatic 

Automatic, 'F' or 'E' format is used depending on the numeric value to be formatted.

rtl_math_StringFormat_E1 

Same 'E', but with only 1 minimum digits in exponent.

Since
LibreOffice 5.0
rtl_math_StringFormat_E2 

Same 'E', but with only 2 minimum digits in exponent.

Since
LibreOffice 5.0
rtl_math_StringFormat_G1 

Same 'G', but with only 1 minimum digits in exponent.

Since
LibreOffice 5.0
rtl_math_StringFormat_G2 

Same 'G', but with only 2 minimum digits in exponent.

Since
LibreOffice 5.0

Function Documentation

SAL_DLLPUBLIC double rtl_math_acosh ( double  fValue)

Returns values of the inverse hyperbolic cosine.

acosh is part of the C99 standard, but not provided by some compilers.

Parameters
fValueThe value x in the term acosh(x).
SAL_DLLPUBLIC bool rtl_math_approxEqual ( double  a,
double  b 
)

Test equality of two values with an accuracy of the magnitude of the given values scaled by 2^-48 (4 bits roundoff stripped).

Attention
approxEqual( value!=0.0, 0.0 ) never yields true.
SAL_DLLPUBLIC double rtl_math_approxValue ( double  fValue)

Rounds value to 15 significant decimal digits.

Parameters
fValueThe value to be rounded.
SAL_DLLPUBLIC double rtl_math_asinh ( double  fValue)

Returns values of the inverse hyperbolic sine.

asinh is part of the C99 standard, but not provided by some compilers.

Parameters
fValueThe value x in the term asinh(x).
SAL_DLLPUBLIC double rtl_math_atanh ( double  fValue)

Returns more accurate atanh(x) for x near 0 than calculating 0.5*log((1+x)/(1-x)).

atanh is part of the C99 standard, but not provided by some compilers.

Parameters
fValueThe value x in the term atanh(x).
SAL_DLLPUBLIC void rtl_math_doubleToString ( rtl_String **  pResult,
sal_Int32 *  pResultCapacity,
sal_Int32  nResultOffset,
double  fValue,
enum rtl_math_StringFormat  eFormat,
sal_Int32  nDecPlaces,
sal_Char  cDecSeparator,
sal_Int32 const *  pGroups,
sal_Char  cGroupSeparator,
sal_Bool  bEraseTrailingDecZeros 
)

Conversions analogous to sprintf() using internal rounding.

+/-HUGE_VAL are converted to "INF" and "-INF", NAN values are converted to "NaN".

Parameters
pResultReturns the resulting byte string. Must itself not be null, and must point to either null or a valid string.
pResultCapacityIf null, pResult is considered to point to immutable strings, and a new string will be allocated in pResult. If non-null, it points to the current capacity of pResult, which is considered to point to a string buffer (pResult must not itself be null in this case, and must point to a string that has room for the given capacity). The string representation of the given double value is inserted into pResult at position nResultOffset. If pResult's current capacity is too small, a new string buffer will be allocated in pResult as necessary, and pResultCapacity will contain the new capacity on return.
nResultOffsetIf pResult is used as a string buffer (i.e., pResultCapacity is non-null), nResultOffset specifies the insertion offset within the buffer. Ignored otherwise.
fValueThe value to convert.
eFormatThe format to use, one of rtl_math_StringFormat.
nDecPlacesThe number of decimals to be generated. Effectively fValue is rounded at this position, specifying nDecPlaces <= 0 accordingly rounds the value before the decimal point and fills with zeros. If eFormat == rtl_math_StringFormat_Automatic and nDecPlaces == rtl_math_DecimalPlaces_Max, the highest number of significant decimals possible is generated. If eFormat == rtl_math_StringFormat_G, nDecPlaces specifies the number of significant digits instead. If nDecPlaces == rtl_math_DecimalPlaces_DefaultSignificance, the default number (currently 6 as implemented by most libraries) of significant digits is generated. According to the ANSI C90 standard the E style will be used only if the exponent resulting from the conversion is less than -4 or greater than or equal to the precision. However, as opposed to the ANSI standard, trailing zeros are not necessarily removed from the fractional portion of the result unless bEraseTrailingDecZeros == true was specified.
cDecSeparatorThe decimal separator.
pGroupsEither null (no grouping is used), or a null-terminated list of group lengths. Each group length must be strictly positive. If the number of digits in a conversion exceeds the specified range, the last (highest) group length is repeated as needed. Values are applied from right to left, for a grouping of 1,00,00,000 you'd have to specify pGroups={3,2,0}.
cGroupSeparatorThe group separator. Ignored if pGroups is null.
bEraseTrailingDecZerosTrailing zeros in decimal places are erased.
SAL_DLLPUBLIC void rtl_math_doubleToUString ( rtl_uString **  pResult,
sal_Int32 *  pResultCapacity,
sal_Int32  nResultOffset,
double  fValue,
enum rtl_math_StringFormat  eFormat,
sal_Int32  nDecPlaces,
sal_Unicode  cDecSeparator,
sal_Int32 const *  pGroups,
sal_Unicode  cGroupSeparator,
sal_Bool  bEraseTrailingDecZeros 
)

Conversions analogous to sprintf() using internal rounding.

+/-HUGE_VAL are converted to "INF" and "-INF", NAN values are converted to "NaN".

Parameters
pResultReturns the resulting Unicode string. Must itself not be null, and must point to either null or a valid string.
pResultCapacityIf null, pResult is considered to point to immutable strings, and a new string will be allocated in pResult. If non-null, it points to the current capacity of pResult, which is considered to point to a string buffer (pResult must not itself be null in this case, and must point to a string that has room for the given capacity). The string representation of the given double value is inserted into pResult at position nResultOffset. If pResult's current capacity is too small, a new string buffer will be allocated in pResult as necessary, and pResultCapacity will contain the new capacity on return.
nResultOffsetIf pResult is used as a string buffer (i.e., pResultCapacity is non-null), nResultOffset specifies the insertion offset within the buffer. Ignored otherwise.
fValueThe value to convert.
eFormatThe format to use, one of rtl_math_StringFormat.
nDecPlacesThe number of decimals to be generated. Effectively fValue is rounded at this position, specifying nDecPlaces <= 0 accordingly rounds the value before the decimal point and fills with zeros. If eFormat == rtl_math_StringFormat_Automatic and nDecPlaces == rtl_math_DecimalPlaces_Max, the highest number of significant decimals possible is generated. If eFormat == rtl_math_StringFormat_G, nDecPlaces specifies the number of significant digits instead. If nDecPlaces == rtl_math_DecimalPlaces_DefaultSignificance, the default number (currently 6 as implemented by most libraries) of significant digits is generated. According to the ANSI C90 standard the E style will be used only if the exponent resulting from the conversion is less than -4 or greater than or equal to the precision. However, as opposed to the ANSI standard, trailing zeros are not necessarily removed from the fractional portion of the result unless bEraseTrailingDecZeros == true was specified.
cDecSeparatorThe decimal separator.
pGroupsEither null (no grouping is used), or a null-terminated list of group lengths. Each group length must be strictly positive. If the number of digits in a conversion exceeds the specified range, the last (highest) group length is repeated as needed. Values are applied from right to left, for a grouping of 1,00,00,000 you'd have to specify pGroups={3,2,0}.
cGroupSeparatorThe group separator. Ignored if pGroups is null.
bEraseTrailingDecZerosTrailing zeros in decimal places are erased.
SAL_DLLPUBLIC double rtl_math_erf ( double  fValue)

Returns values of the Errorfunction erf.

erf is part of the C99 standard, but not provided by some compilers.

Parameters
fValueThe value x in the term erf(x).
SAL_DLLPUBLIC double rtl_math_erfc ( double  fValue)

Returns values of the complement Errorfunction erfc.

erfc is part of the C99 standard, but not provided by some compilers.

Parameters
fValueThe value x in the term erfc(x).
SAL_DLLPUBLIC double rtl_math_expm1 ( double  fValue)

Returns more accurate e^x-1 for x near 0 than calculating directly.

expm1 is part of the C99 standard, but not provided by some compilers.

Parameters
fValueThe value x in the term e^x-1.
SAL_DLLPUBLIC double rtl_math_log1p ( double  fValue)

Returns more accurate log(1+x) for x near 0 than calculating directly.

log1p is part of the C99 standard, but not provided by some compilers.

Parameters
fValueThe value x in the term log(1+x).
SAL_DLLPUBLIC double rtl_math_pow10Exp ( double  fValue,
int  nExp 
)

Scales fVal to a power of 10 without calling pow() or div() for nExp values between -16 and +16, providing a faster method.

Parameters
fValueThe value to be raised.
nExpThe exponent.
Returns
fVal * pow(10.0, nExp)
SAL_DLLPUBLIC double rtl_math_round ( double  fValue,
int  nDecPlaces,
enum rtl_math_RoundingMode  eMode 
)

Rounds a double value.

Parameters
fValueSpecifies the value to be rounded.
nDecPlacesSpecifies the decimal place where rounding occurs. Must be in the range -20 to +20, inclusive. Negative if rounding occurs before the decimal point.
eModeSpecifies the rounding mode.
SAL_DLLPUBLIC double rtl_math_stringToDouble ( sal_Char const *  pBegin,
sal_Char const *  pEnd,
sal_Char  cDecSeparator,
sal_Char  cGroupSeparator,
enum rtl_math_ConversionStatus pStatus,
sal_Char const **  pParsedEnd 
)

Conversion analogous to strtod(), convert a string representing a decimal number into a double value.

Leading tabs (0x09) and spaces (0x20) are eaten. Overflow returns +/-HUGE_VAL, underflow 0. In both cases pStatus is set to rtl_math_ConversionStatus_OutOfRange, otherwise to rtl_math_ConversionStatus_Ok. "INF", "-INF" and "+/-1.#INF" are recognized as +/-HUGE_VAL, pStatus is set to rtl_math_ConversionStatus_OutOfRange. "NaN" and "+/-1.#NAN" are recognized and the value is set to +/-NAN, pStatus is set to rtl_math_ConversionStatus_Ok.

Parameters
pBeginPoints to the start of the byte string to convert. Must not be null.
pEndPoints one past the end of the byte string to convert. The condition pEnd >= pBegin must hold.
cDecSeparatorThe decimal separator.
cGroupSeparatorThe group (aka thousands) separator.
pStatusIf non-null, returns the status of the conversion.
pParsedEndIf non-null, returns one past the position of the last character parsed away. Thus if [pBegin..pEnd) only contains the numerical string to be parsed, *pParsedEnd == pEnd on return. If no numerical (sub-)string is found, *pParsedEnd == pBegin on return, even if there was leading whitespace.
SAL_DLLPUBLIC double rtl_math_uStringToDouble ( sal_Unicode const *  pBegin,
sal_Unicode const *  pEnd,
sal_Unicode  cDecSeparator,
sal_Unicode  cGroupSeparator,
enum rtl_math_ConversionStatus pStatus,
sal_Unicode const **  pParsedEnd 
)

Conversion analogous to strtod(), convert a string representing a decimal number into a double value.

Leading tabs (U+0009) and spaces (U+0020) are eaten. Overflow returns +/-HUGE_VAL, underflow 0. In both cases pStatus is set to rtl_math_ConversionStatus_OutOfRange, otherwise to rtl_math_ConversionStatus_Ok. "INF", "-INF" and "+/-1.#INF" are recognized as +/-HUGE_VAL, pStatus is set to rtl_math_ConversionStatus_OutOfRange. "NaN" and "+/-1.#NAN" are recognized and the value is set to +/-NAN, pStatus is set to rtl_math_ConversionStatus_Ok.

Parameters
pBeginPoints to the start of the Unicode string to convert. Must not be null.
pEndPoints one past the end of the Unicode string to convert. The condition pEnd >= pBegin must hold.
cDecSeparatorThe decimal separator.
cGroupSeparatorThe group (aka thousands) separator.
pStatusIf non-null, returns the status of the conversion.
pParsedEndIf non-null, returns one past the position of the last character parsed away. Thus if [pBegin..pEnd) only contains the numerical string to be parsed, *pParsedEnd == pEnd on return. If no numerical (sub-)string is found, *pParsedEnd == pBegin on return, even if there was leading whitespace.