> > [...] > >> So leave the testing to just ints and document on the user guide that is > >> what we are testing. > > > > +1 > > OK. That seems simplest. > > Given all the stress tests will be rerun shall I go ahead and reorder the > existing files, user guide .apt file and the GeneratorsList to be in the > order of the RandomSource enum?
We could wait for the new results before updating the site. > > > Big/Little Endian for Dieharder: > > I’ve spent some time looking at the source code for Dieharder. It reads > binary file data using this (taken from libdieharder/rng_file_input_raw.c): > > unsigned int iret; > // ... > fread(&iret,sizeof(uint),1,state->fp); > > So it reads single unsigned integers using fread(). > > Given that it is possible to run die harder using numbers from ascii and > binary input files I set up a test. I created them using a RNG with the same > seed with the standard output from a DataOutputStream and the byte reversed > output using Integer.reverseBytes. Here’s what happens: > > > dieharder -g 201 -d 0 -f raw.bin.rev > diehard_birthdays| 0| 100| 100|0.89220858| PASSED > > dieharder -g 202 -d 0 -f raw.txt > diehard_birthdays| 0| 100| 100|0.89220858| PASSED > > > dieharder -g 201 -d 0 -f raw.bin > diehard_birthdays| 0| 100| 100|0.30776452| PASSED > > dieharder -g 202 -d 0 -f raw.txt.rev > diehard_birthdays| 0| 100| 100|0.30776452| PASSED > > > cat raw.bin | dieharder -g 200 -d 0 > diehard_birthdays| 0| 100| 100|0.30776452| PASSED > > > Note the reversed byte sequence (.rev suffix) is required to get the same > results from the binary (.bin) file as from the text (.txt) file. > > So the binary read of Dieharder is using the little endian representation, as > was required for TestU01. > > I had modified the stdin2testu01.c bridge to detect if the system was little > endian and then correct the input data by reversing the bytes. It may be a > better idea to write a test c program to detect the endianness of the system > for reference. Then update the stress test benchmark to have an argument for > little or big endian output when piping the int data to the command line > program. > > I think it is important to get the endianness of the data correct. At least > for Dieharder it runs tests using tuples of bits from the data which can span > multiple bytes. For example the sts_serial test (-d 102) uses overlapping > n-tuples of bits with n from 1 to 16. Other tests using non overlapping > tuples such as rgb_bitdist (-d 200) use n 1 to 12. > > Reversing the bytes in the Java code is the easiest option. +1 [With an option flag for selecting whether the output should be BE or LE.] Best, Gilles > Others are: > > - Write binary data to file and then run it using that. This will end up > looping the file though and repeating the sequence unless the binary file is > huge. > - Call Dieharder from a bridge program using the libdieharder API. I’ve not > checked if there is an API method call for Dieharder to run everything. > > Alex --------------------------------------------------------------------- To unsubscribe, e-mail: dev-unsubscr...@commons.apache.org For additional commands, e-mail: dev-h...@commons.apache.org
