Re: read real*8 binary

*To*: mathgroup at smc.vnet.net*Subject*: [mg97504] Re: read real*8 binary*From*: David Bailey <dave at removedbailey.co.uk>*Date*: Sat, 14 Mar 2009 05:41:05 -0500 (EST)*References*: <gp7vus$1f4$1@smc.vnet.net>

Jan Schmedes wrote: > Dear group, > > I have a fortran program which writes a real array into a binary file. > This binary file I could read without problems using > Import["..."."Real32"]; But when I changed real to real*8 in the > fortran program I could not read the file anymore (I used "Real64" > instead of "Real32"), meaning I get numbers like 10^275. I used the > same fortran compiler (ifort 10) and the same computer (Mac Pro) in > both computations. > Anyone has an idea why this does not work??? > > Thank you! > > Jan > This sounds rather puzzling to me.I would write a mini Fortran program to output a number of REAL*8 numbers with known bit patterns - possibly equivalencing them to integers so that you can print out the exact bit pattern. Then you can check with a hex editor that the resultant file actually contains the bit patterns you expect. My guess is that there is a typo in your program somewhere. Have you checked that your Fortran program is actually producing the numbers you expect. For example, when you changed to REAL*8, did you end up calling a function that required a REAL*4 with an argument that was now REAL*8 perhaps. David Bailey http://www.dbaileyconsultancy.co.uk