第九十章 Caché 函数大全 $ZLOG 函数

返回指定正数值表达式的以10为底的对数值。

大纲

$ZLOG(n)

参数

• n 任何正数、非零数，可以指定为值、变量或表达式。

描述

$ZLOG返回以10为底的对数值n。

指定零或负数会导致<ILLEGAL VALUE>错误。

对应的自然对数(base e)函数是$ZLN。

示例

以下示例写入整数1到10的以10为基数的对数:

/// d ##class(PHA.TEST.Function).ZLOG()
ClassMethod ZLOG()
{
	FOR x=1:1:10 {
		WRITE !,"The log of ",x," = ",$ZLOG(x) 
	}
	QUIT
}

DHC-APP>d ##class(PHA.TEST.Function).ZLOG()
 
The log of 1 = 0
The log of 2 = .301029995663981195
The log of 3 = .477121254719662437
The log of 4 = .60205999132796239
The log of 5 = .698970004336018805
The log of 6 = .778151250383643633
The log of 7 = .845098040014256831
The log of 8 = .903089986991943586
The log of 9 = .954242509439324875
The log of 10 = 1

DHC-APP>WRITE $ZLOG($ZPI)
.4971498726941338541

DHC-APP>WRITE $ZLOG(.5)
-.301029995663981195

DHC-APP>WRITE $ZLOG(0)
 
WRITE $ZLOG(0)
^
<ILLEGAL VALUE>