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export - Size of exported MX files


I have a problem with the following piece of Mathematica code:


A = Import["fileA.mx"];
B = Import["fileB.mx"];

The following evaluates to True:


A === B

however the size of one file is about 10 times greater then the size of the other one.



Both files were created in Mathematica using the same Export[".mx" , ] incantation. What's going on here?



Answer



I think I figured out what was going on.It looks like it all boils down to how MX stores files. I'll use a small example (in reality the tables were much larger), exporting:


{Table[0 , {64} , {64}] , 1 , 2 , 3 , {Table[0 , {64} , {64}]}}


will produce a significantly larger MX file size then exporting:


{zerotable , 1 , 2 , 3 , {zerotable}}


with


zerotable = Table[0 , {64} , {64}]


evaluated beforehand.


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