Delphi

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Abs

Ceil

Exp

Floor

frac

Frexp

int

intpower

Ldexp

max

min

返回

(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) = -2

Ceil(2.8) = 3

Ceil(-1.0) = -1)

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。)

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

Call Floor to obtain the highest integer less than or equal to X. For example:

Floor(-2.8) = -3

Floor(2.8) = 2

Floor(-1.0) = -1

Note: 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) = -3

Floor(2.8) = 2

Floor(-1.0) = -1

注意：X的绝对值必须小于整形数的最大值)

返回

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)。)

var
a,b:Real;
begin
a := 1.54;
b := frac(a);
end;
此时，a= 1.54,b=0.54

返回

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

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。)
 

var 

  R: Real;
begin
  R := Int(123.456);    { 123.0 }
  R := Int(-123.456);   { -123.0 }
end;

返回

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)

返回

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

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;

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

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

Use Pi in mathematical calculations that require pi, the ratio of a circle's 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

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:

Coefficients[0] + Coefficients[1]*X + ... + Coefficients[N]*(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：Coefficients[0]+
coefficients[1]*X+…..+Cofficients[n]*[X**N])

返回

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

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)

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

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)

返回

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)

返回

The Trunc function truncates a real-type value to an integer-type value. X is a real-type expression. Trunc returns an Int64 value that is the value of X rounded toward zero.

If the truncated value of X is not within the Int64 range, an EInvalidOp exception is raised.