Delphi中的算术运算函数.doc

AbsCeilExpFloorfracFrexpintintpowerLdexpmaxminpipolypowerroundsqrttruncsqr函数名ABS简要介绍：Returns an absolute value. (取绝对值）所属单元：System定义：function Abs(X);详细解释：Abs returns the absolute value of the argument, X.X is an integer-type or real-type expression.(Abs函数用于返回变量X的绝对值,X可以是一个整形的变量或实数型的变量)返回函数名ceil简要介绍：Rounds variables up toward positive infinity.所属单元：Math定义：function Ceil(X: Extended):Integer详细解释：Call Ceil to obtain the lowest integer greater than or equal to X. The absolute value of X must be less than MaxInt. For example:Ceil(-2.8) = -2Ceil(2.8) = 3Ceil(-1.0) = -1 (调用ceil函数，返回大于或等于x的最小整数值。X的绝对值一定要小于最大整数值。例如：Ceil(-2.8) = -2Ceil(2.8) = 3Ceil(-1.0) = -1)返回函数名Exp简要介绍：Returns the exponential of X.(Exp函数返回自然对数基底E的X次幂。)所属单元：System定义：function Exp(X: Real): Real;详细解释：Exp returns the value of e raised to the power of X, where e is the base of the natural logarithms.(Exp返回e的X次幂的值，其中e是一个自然对数基底。)范例：var e : real; S : string;begin e := Exp(1.0); Str(ln(e):3:2, S); S := e = + FloatToStr(e) + ; ln(e) = + S; Canvas.TextOut(10, 10, S);end;返回函数名Floor简要介绍：Rounds variables toward negative infinity.(取小于给定值的最大整数)所属单元：Math定义：function Floor(X: Extended): Integer;详细解释：Call Floor to obtain the highest integer less than or equal to X. For example:Floor(-2.8) = -3Floor(2.8) = 2Floor(-1.0) = -1Note: The absolute value of X must be less than MaxInt. (使用Floor函数以取得小于等于X的最大的整数，如：Floor(-2.8) = -3Floor(2.8) = 2Floor(-1.0) = -1注意：X的绝对值必须小于整形数的最大值)返回函数名Frac简要介绍：Returns the fractional part of a real number(返回一个实数的小数部分)所属单元：System定义：function Frac(X: Extended): Extended;详细解释：The Frac function returns the fractional part of the argument X.X is a real-type expression. The result is the fractional part of X; that is, Frac(X) = X - Int(X). (Frac函数返回参数X的小数部分，X是一个实型数,该函数的作用等价于Frac(X)=X-Int(X)。)范例：vara,b:Real;begina := 1.54;b := frac(a);end;此时，a= 1.54,b=0.54返回函数名Frexp简要介绍：Separates the Mantissa and Exponent of X(分解开X的尾数和指数。)所属单元：Math定义：procedure Frexp(X: Extended; var Mantissa: Extended; var Exponent: Integer) register;详细解释：Frexp returns the mantissa of X as Mantissa and the exponent as Exponent.(Frexp函数返回X的尾数用变量Mantissa和指数用变量Exponent)。返回函数名int简要介绍：Returns the integer part of a real number.(返回一个实数类型的整数部分)所属单元：System定义：function Int(X: Extended): Extended;详细解释：Int returns the integer part of X; that is, X rounded toward zero. X is a real-type expression.(Int函数返回参数X的整数部分，X为实数类型，函数结果为X经过负向舍入(向0舍入)实数。) 范例：var R: Real;begin R := Int(123.456); 123.0 R := Int(-123.456); -123.0 end;返回函数名Intpower简要介绍：Calculates the integral power of a base value.(计算基数的整数幂。)所属单元：Math定义：function IntPower(Base: Extended; Exponent: Integer): Extended register;详细解释：IntPower raises Base to the power specified by Exponent (计算基数的整数幂。base为基数，Exponent为指数)范例：返回函数名Ldexp简要介绍：Calculates X * (2*P)所属单元：Math定义：function Ldexp(X: Extended; P: Integer): Extended register;详细解释：Ldexp returns X times (2 to the power of P).(Ldexp计算X*(2*P)，返回X的(2的P次幂)次幂。)返回函数名Max简要介绍：Returns the greater of two numeric values.(取两个数中的最大值)所属单元：Math定义：function Max(A,B: Integer): Integer; overload;function Max(A,B: Int64): Int64; overload;function Max(A,B: Single): Single; overload;function Max(A,B: Double): Double; overload;function Max(A,B: Extended): Extended; overload;详细解释：Call Max to compare two numeric values. Max returns the greater value of the two.(返回两个数值中的最大值。调用Max比较两个数值。它返回二者中较大的一个值。)返回函数名Min简要介绍：Returns the lesser of two numeric values.(取两个数的最小值)所属单元：Math定义：function Min(A,B: Integer): Integer; overload;function Min(A,B: Int64): Int64; overload;function Min(A,B: Single): Single; overload;function Min(A,B: Double): Double; overload;function Min(A,B: Extended): Extended; overload;详细解释：Call Min to compare two numeric values. Min returns the smaller value of the two.(返回两个数值中的最小值。调用Max比较两个数值，它返回二者中较小的一个值。)返回函数名pi简要介绍：Returns 3.1415926535897932385. (返回3.1415926535897932385.)所属单元：System定义：function Pi: Extended;详细解释：Use Pi in mathematical calculations that require pi, the ratio of a circles circumference to its diameter. Pi is approximated as 3.1415926535897932385.(使用Pi函数精确计算返回圆周率Pi，圆周率是一个圆的周长除以它的直径。Pi的值近似于3.1415926535897932385.)返回函数名poly(本条翻译无把握)简要介绍：Evaluates a uniform polynomial of one variable at the value X.所属单元：Math定义：function Poly(X: Extended; const Coefficients: array of Double): Extended;详细解释：Call Poly to evaluate the polynomial represented by the Coefficients parameter at the point where the variable equals the value of the X parameter. The coefficients are ordered in increasing powers of X:Coefficients0 + Coefficients1*X + . + CoefficientsN*(X*N)(Poly估计一个变量在同一多项式的X值。调用Poly评估由Coefficients参数表达的多项式在一位置的值等同于X参数的值。参数是顺序的以X的幂增加：Coefficients0+coefficients1*X+.+Cofficientsn*X*N)返回函数名power简要介绍：Raises Base to any power.(取一个实数的幂）所属单元：Math定义：function Power(Base, Exponent: Extended): Extended;详细解释：Power raises Base to any power. For fractional exponents or exponents greater than MaxInt, Base must be greater than 0.（返回一个实数的幂。 当指数Exponent为小数或大于MaxInt时，底数Base必须大于0.）返回函数名Round简要介绍：Returns the value of X rounded to the nearest whole number.(对一个实数进行四舍五入)所属单元：System定义：function Round(X: Extended): Int64;详细解释：The Round function rounds a real-type value to an integer-type value.X is a real-type expression. Round returns an Int64 value that is the value of X rounded to the nearest whole number. If X is exactly halfway between two whole numbers, the result is always the even number.If the rounded value of X is not within the Int64 range, a run-time error is generated, which can be handled using the EInvalidOp exception.(Round返回X向最近整数值的舍入。函数将一个实型值舍入为一个整型值。X是一个实型表达式。Round返回一个长整型值，是离X最近的整数值。如果X是两个整数值的正中间，结果是绝对值最大的一个。如果X的舍入值不是在长整型范围内，一个运行时间错误将产生，可以使用EinvalidOp异常来处理)范例：var S, T: string;begin Str(1.4:2:1, T); S := T + rounds to + IntToStr(Round(1.4) + #13#10; Str(1.5:2:1, T); S := S + T + rounds to + IntToStr(Round(1.5) + #13#10; Str(-1.4:2:1, T); S := S + T + rounds to + IntToStr(Round(-1.4) + #13#10; Str(-1.5:2:1, T); S := S + T + rounds to + IntToStr(Round(-1.5); MessageDlg(S, mtInformation, mbOk, 0);end;返回函数名Sqr简要介绍：Returns the square of a number.(取给定值的平方)所属单元：System定义：function Sqr(X: Extended): Extended;详细解释：The Sqr function returns the square of the argument.X is a floating-point expression. The result, of the same type as X, is the square of X, or X*X.(Sqr返回X得平方值，X是一个浮点型的数,返回值的类型与X 相同,值为X*X)范例：var S, Temp: string;begin Str(Sqr(5.0):3:1, Temp); S := 5 squared is + Temp + #13#10; Str(Sqrt(2.0):5:4, Temp); S := S + The square root of 2 is + Temp; MessageDlg(S, mtInformation, mbOk, 0);end;返回函数名sqrt简要介绍：Returns the square root of X.所属单元：System定义：function Sqrt(X: Extended): Extended;详细解释：X is a floating-point expression. The result is the square root of X.(取X的平方根,X是一个浮点数，返回值也是个浮点数)范例：var S, Temp: string;begin Str(Sqr(5.0):3:1, Temp); S := 5 squared is + Temp + #13#10; Str(Sqrt(2.0):5:4, Temp); S := S + The square root of 2 is + Temp; MessageDlg(S, mt