FORTRAN READ（） [英] FORTRAN READ()

问题描述

READ（）在FORTRAN中做什么？

>

例如：

  READ（1,82）
  

解决方案

1是文件句柄，您必须打开正确的公开呼叫。
82是一种引用格式的标签，意味着您将如何以视觉格式报告数据。

 程序foo 
隐式无
整数:: i 
双精度:: a 
 
写（*，*）'给我一个整数和一个浮点数'
 read（*，82）i，a 
 write（*，82）i，
 82格式（I4，F8.3）
结束程序
  
 
 
如果我运行程序现在，我没有完全遵循这种格式，程序会发出抱怨和崩溃，因为前4列预期会表示一个整数（由于I4格式），5 3。是不是一个有效的整数
 
 
  $ ./a.out 
给我一个整数和一个浮点数
 5 3.5 
在文件test.f（Unit 5）的第7行
 Traceback：不可用，用-ftrace = frame或-ftrace = full编译
 Fortran运行时错误：整数阅读
  
然而，正确的规格（请注意数字5之前的三个空格）将执行正确操作（有一点宽容，这不是严格的）
  $ ./a.out 
给我一个整数和一个浮点数
 5 3.5 
 5 3.500 
 $ 
  
 
Excuse me if this is a duplicate question, but I didn't see anything exactly like this.

What does READ() do in FORTRAN?

For example:
READ(1,82)

解决方案
1 is the file handle, which you have to open with the proper open call.
82 is a label that references a format, meaning how you will report the data in terms of visual formatting.
        program foo
        implicit none
        integer :: i
        double precision :: a

        write (*,*) 'give me an integer and a float'
        read (*,82) i,a
        write (*,82) i,a
82      format (I4, F8.3)
        end program
In this example, the program accepts from the standard input (whose unit number is not specified, and so I put a *) an integer and a floating point value. the format says that the integer occupies the first four columns, then I have a float which stays in 8 columns, with 3 digits after the decimal point

If I run the program now, and I don't follow exactly this format, the program will complain and crash, because the first 4 columns are expected to represent an integer (due to the I4 format), and "5 3." is not a valid integer
$ ./a.out 
 give me an integer and a float
5 3.5
At line 7 of file test.f (Unit 5)
Traceback: not available, compile with -ftrace=frame or -ftrace=full
Fortran runtime error: Bad value during integer read
However, a correct specification (please note the three spaces before the number 5) will perform the correct operation (with a little tolerance, it's not that strict)
$ ./a.out 
 give me an integer and a float
   5 3.5
   5   3.500
$ 


                        
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