Will do. I have a few other things on hand right now though but I'll definitely get to it eventually. In the meantime, anyone else feel free to review this.
On Thursday, May 9, 2013 8:17:30 PM UTC-7, Kenneth Lin wrote: > > Hey everyone, > > So I'm not sure if I discovered two bugs in random_matrix or if I'm > reading the documentation wrong. Firstly, in the documentation, it says: > > Random integer matrices. With no arguments, the majority of the >> entries are -1 and 1, never zero, and rarely "large." >> sage: random_matrix(ZZ, 5, 5) >> [ -8 2 0 0 1] >> [ -1 2 1 -95 -1] >> [ -2 -12 0 0 1] >> [ -1 1 -1 -2 -1] >> [ 4 -4 -6 5 0] > > > Now, it appears that there are 0's in the matrix produced. This also > happens when I run the exact function above. Is this a bug in the > documentation or the function? > > Secondly, the documentation says this about random matrices in rational > fields: > > Random rational matrices. Now "num_bound" and "den_bound" control >> the generation of random elements, by specifying limits on the >> absolute value of numerators and denominators (respectively). >> Entries will be positive and negative (map the absolute value >> function through the entries to get all positive values), and zeros >> are avoided unless the density is set. If either the numerator or >> denominator bound (or both) is not used, then the values default to >> the distribution for ZZ described above that is most frequently >> positive or negative one. > > > > However, when I run <code>random_matrix(QQ, 10, 10)</code>, it appears all > the numbers are either 0, 1, 2, -1, -2, 1/2, and -1/2. This doesn't seem to > be the "most frequently positive or negative one" distribution, but instead > the "uniform" one for integers. I could imagine it being such that two > numbers every time with the uniform distribution as the numerator and > denominator and the two are divided. Could anyone else verify this behavior? > > Thanks > -- You received this message because you are subscribed to the Google Groups "sage-devel" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To post to this group, send email to [email protected]. Visit this group at http://groups.google.com/group/sage-devel?hl=en. For more options, visit https://groups.google.com/groups/opt_out.
