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Solve : 7-zip Cannot Compress? |
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Answer» I have got the first billion digits of pi in .txt FORMAT. It is 1.5 GB big. I'm planning on sharing it on the internet, but I don't want to put a 1.5 GB text file up there. So, I tried to compress it using 7-zip. Unfortunately, 7-zip failed to compress it...it came up with a message: "system cannot allocate the required amount of memory." Is the nonobjective speed or size? The objective was reduced size, for web sharing. Time taken to compress is not, I think, an issue. This approach might be fun: With curl.exe http://curl.haxx.se/ you can download a range of pi digits so if you want to examine them you don't even need the billion digit file to be stored locally. Store the first 10 digits of Pi in pi-10-digits.txt (the start character is 2 because the first character of the file is the decimal point) curl -o pi-10-digits.txt -r 2-11 http://stuff.mit.edu/afs/sipb/contrib/pi/pi-billion.txt result: 1415926535 Store the 50 digits of Pi starting at the 70th digit in pi-50-digits-from70.txt curl -o pi-50-digits-from-70.txt -r 71-121 http://stuff.mit.edu/afs/sipb/contrib/pi/pi-billion.txt result: 406286208998628034825342117067982148086513282306647 Salmon Trout, you are beyond brilliant! How do you find such things? Are you riving inside of Google?Came back, and saw all these great, helpful replies.....thanks very much. And Salmon Trout, the curl.exe was very INTERESTING! Thanks!You can use curl.exe to get a range of bytes (or in this case, characters) from a local file. You have to convert the file path to a file url starting file:/// and using forward slashes instead of backslashes: From the local file D:\Pi\pi-billion.txt, create a text file with the first 10 digits of Pi (the start character is 2 because the first character of the file is the decimal point): curl -o pi-10-digits.txt -r 2-11 file:///d:/pi/pi-billion.txt Thus you see that curl.exe can be used as a local file splitter. I found a pi calculator program for Windows by Fabrice Bellard http://www.bellard.org/pi/pi2700e9/tpi-0.9.3-win.zip I calculated the first billion places of Pi on my home PC (AMD Phenom II 945, 4GB RAM, Windows 7 64 bit) and it took 1 hour 4 minutes. I chose to limit RAM usage to 1 GB and also to store some of the intermediate results on disk rather than keep them in RAM. If I had gone for the all-RAM option it would have been a lot quicker but the PC would have been quite slow at doing other tasks. I compared the first million digits of my CALCULATION with the first million of the MIT billion digit file and they are the same. Next: compare the full billion. Of course it won't prove that either set is "right"... Pi' are round... |
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