为什么我收到以下错误
d = Atan ( 1_Real32 / 110443_Real32 )
1
Error: 'x' argument of 'atan' intrinsic at (1) must
be REAL or COMPLEX
有趣的是，当我使用
时，我没有遇到任何问题d = Atan ( Real(1,Real32) / Real(110443,Real32) )
答案 0 :(得分：4)
The value 1_Real32 is an int-literal-constant (R407, Fortran2008 4.4.2.2 5).
To get a real value instead you need to change it to 1._Real32. The presence of the decimal makes it a real-literal-constant (R413, Fortran2008 4.4.2.3 6).
Remember that Real32 in your code is just a number, e.g. 4 and it only specifies a kind, not a type e.g. 1_4 is an integer of kind 4 and 1._4 is a real of kind 4.
You don't encounter the error in the second example because the intrinsic real() always returns a real value including when supplied an integer as its first argument.
答案 1 :(得分：3)
casey's answer是完全正确的，但在回答这个问题时可能需要明确指出一件事。
内在$xml->xpath(//d:ServiceId[.= '123'])接受整数参数并返回默认或指定种类的实数。 <?xml>
<feed xmlns:m="" xmlns:d="">
<entry>
<content>
<m:properties>
<d:ServiceId>123</d:ServiceId>
<d:ServiceName>Service 1</d:ServiceName>
<d:DMA>DMA 1</d:DMAName>
<d:Abbreviation>ABC</d:Abbreviation>
</m:properties>
</content>
<content>
<m:properties>
<d:ServiceId>456</d:ServiceId>
<d:ServiceName>Service 2</d:ServiceName>
<d:DMA>DMA 2</d:DMAName>
<d:Abbreviation>DEF</d:Abbreviation>
</m:properties>
</content>
<content>
<m:properties>
<d:ServiceId>789</d:ServiceId>
<d:ServiceName>Service 3</d:ServiceName>
<d:DMA>DMA 3</d:DMAName>
<d:Abbreviation>HIJ</d:Abbreviation>
</m:properties>
</content>
</entry>
</feed>
</xml>
是整数（如果real是整数的有效种类数），1_real32是真实的。