Re: Mathematica 9 does not read mathematica 8 ".mx" files

*To*: mathgroup at smc.vnet.net*Subject*: [mg129100] Re: Mathematica 9 does not read mathematica 8 ".mx" files*From*: Bill Rowe <readnews at sbcglobal.net>*Date*: Sat, 15 Dec 2012 05:49:41 -0500 (EST)*Delivered-to*: l-mathgroup@mail-archive0.wolfram.com*Delivered-to*: l-mathgroup@wolfram.com*Delivered-to*: mathgroup-newout@smc.vnet.net*Delivered-to*: mathgroup-newsend@smc.vnet.net

On 12/14/12 at 2:58 AM, noomenov at gmail.com (noomen mechri) wrote: >Thanks for your reply! yes, that's what I had to do ... rerun the >whole calculation on M9 which again took a few hours!! (I know ... >not good at optimizing code) But then what is the purpose of having >.mx files to save the workspace variables for future use ... if they >can only be read by the version in which they have been produced ... >it is senseless ... No. It is still useful for saving time from one session to the next in the same version on the same machine. It is just the .mx format cannot be used for something more than this at this point in time. Note, it is possible to create data files that do preserve variables that can be used across versions and platforms. For example, if you create a text file with a={{4,3,5},{3.24,5.38,3.98},{0,1,0}}; in it and load it with Get, then the variable a will be created with the expected value in any version of Mathematica on any platform. True, this will not load as quickly as a .mx file and you have more work to do to create this type of file form Mathematica than simply using DumpSave. Also, if you think about it, minimum load/write times for computations would be achieved by simply writing out whatever is in memory to storage in the format it is in. Anything else requires some CPU effort to modify format during the load/write process. And if you forgo any processing during the load/write process to minimize the time these take, there can never be an expectation the saved files can work across versions or platforms.