LinuxQuestions.org - [SOLVED] Gfortran's strange behavior

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Gfortran's strange behavior

Hi there,

My environment is Oracle VM (Ubuntu)==>GFortran.

I have a problem with my GFortran. I have an input file (anglesV1.dat) with two columns of numbers:

Code:

  0.7439803D-01  0.1107149D+01        

  0.7321435D-01  0.1099019D+01        

  0.7203546D-01  0.1090621D+01        

  0.7086159D-01  0.1081944D+01        

  0.6969303D-01  0.1072974D+01        

  0.6853005D-01  0.1063698D+01        

  0.6737297D-01  0.1054101D+01        

  0.6622212D-01  0.1044169D+01

Then I run a subroutine that reads them and prints them on the screen:

Code:

    subroutine determinant                

          real*8 :: phi,theta

          integer*4 :: counter

          open (unit=1,file='anglesV1.dat', status='old')

          counter = 0

10        FORMAT (2F12.5)

          do while (counter .lt. 20)

            counter = counter + 1

            read (1,10) theta,phi

            write (6,10) theta,phi

          enddo

          close(unit=1)

        end subroutine determinant

This is what I get in the terminal:

Code:

    0.74398  -10.11071

    0.73214  -10.10990

    0.72035  -10.10906

    0.70862  -10.10819

    0.69693  -10.10729

    0.68530  -10.10636

    0.67373  -10.10541

    0.66222  -10.10441

I don't understand the result. In the first column all exponents are -1. It means that the numbers (mantissas) must be multiplied by 10 to the power -1, meaning it is 1/10, correct? So when I use F12.6 format the numbers in the first column should come out like this:

Code:

    0.074398  

    0.073214 etc.,

In the second column the exponents are +1 meaning that the mantissas should be multiplied by 10.0, that is:

Code:

                1.107149    

                1.099019

Why do I have negative sign in the output for the second column?

Please help, thanks.

This

Code:

  0.7439803D-01  0.1107149D+01        

  0.7321435D-01  0.1099019D+01        

  0.7203546D-01  0.1090621D+01        

  0.7086159D-01  0.1081944D+01        

  0.6969303D-01  0.1072974D+01        

  0.6853005D-01  0.1063698D+01        

  0.6737297D-01  0.1054101D+01        

  0.6622212D-01  0.1044169D+01

Is not 2F12.5, it's 2D15.7, so when you tell it to parse it as 2F12.5 you'll get the wrong result.
Reading this line

Code:

0.7439803D-01 0.1107149D+01

as 2F12.5, will see this

Code:

0.7439803D

for the first number, and this

Code:

-01 0.11071

for the second number.

Either remove the format code from the read, or change it to match the format of the data you're reading.

I am in AWE with you, suicidaleggroll. I will try it in a minute. Many thanks.

It's awesome! It worked. Another lesson for me. Thanks again.