Graph Software for Scientists and Engineers

Trigonometric and General Math Functions

This page provides a brief description of the functions available in the Y=f(X) command and similar commands. For a more detailed description of each function, click on the function name. Function names are not case specific.

Please note: All dates taken as input arguments to these functions are Excel 1900 date system serial numbers, the internal date format used throughout DPlot.


ABSAbsolute value
ACOSArccosine (inverse cosine)
ACOSHInverse hyperbolic cosine
ASINArcsine (inverse sine)
ASINHInverse hyperbolic sine
ATANArctangent (inverse tangent)
ATAN2Arctangent (inverse tangent)
ATANHInverse hyperbolic tangent
BESSELJBessel function of the first kind
BESSELYBessel function of the second kind
CDFCumulative distribution function
CEILRounds a number up
COSHHyperbolic cosine
DATEExcel 1900 date system serial number that represents the input year, month, and day
DAYDay of the month from a date (1-31)
ERFError function
ERFCComplementary error function
EXPExponent (inverse of log)
FLOORRounds a number down
FPOWERRaises a number to a fractional power
GCDGreatest common divisor
LCMLeast common multiple
LOGNatural (base-e) logarithm
LOG10Base-10 logarithm
MAXMaximum of two values
MINMinimum of two values
MODRemainder after division
MONTHMonth from a date (1=January)
MROUNDReturns a number rounded to the desired multiple
NORMDISTNormal distribution
NORMDISTCDFCumulative distribution function (integral of NORMDIST)
NORMRANDNormally-distributed random number
PMTCalculates loan payments
RANDBETWEENUniformly-distributed random number between specified limits
RNDRandom whole number
ROUNDRounds a number to a specified number of digits
SIGNSign of a number
SINHHyperbolic sine
SQRTPositive square root
SUMAdd result of argument to previous result. Useful for Taylor series.
TANHHyperbolic tangent
WEEKDAYDay of the week from a date (1=Sunday, 7=Saturday)
WEEKNUMNumber of weeks since start of year for a given date
YEARYear from a date

Excel date system

DPlot uses Microsoft Excel for Windows 1900 Date System serial numbers for date values, with one exception: Excel limits date input to January 1, 1900 through December 31, 2078. DPlot allows dates between October 15, 1582 and December 31, 9999.

In this system a serial number of 1 corresponds to January 1, 1900. The following code converts a month, day, and year to the Excel 1900 Date System serial number for years between 1900 and 2099, inclusive.

if( Year >= 1900 && Year <= 2099 )
    if( Month > 2 )
Windows 10,
Windows 8,
Windows 7, 2008,
Vista, XP, NT,
ME, 2003, 2000,
Windows 98, 95
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