Help Providing a Module

*To*: mathgroup at smc.vnet.net*Subject*: [mg39696] Help Providing a Module*From*: "flip" <flip_alpha at safebunch.com>*Date*: Sat, 1 Mar 2003 22:06:16 -0500 (EST)*Sender*: owner-wri-mathgroup at wolfram.com

Hello, can someone help with this? I have a = {-1, 2, 3, 61}; q = {{{-1, 1}, {3, 2}}, {{-1, 1}, {2, 3}, {3, 6}, {61, 1}}, {{2, 2}, {61, 1}}} I want a module vects[a_, q_ ] that will produce (notice, the number of vectors is the length of q and the number of values within each vector is the length of "a": evects = {{1 , 0, 0, 0} , {1, 0, 0, 1}, {0, 1, 0, 0}} We see that the first values of the submatrices in q have -1 and 3, and those exist in "a", so in each position where the values in a exists, we take the mod base 2 of the second value of that value. So for example, we have {-1, 1} and {-1} exists in a, thus we take Mod[1, 2] = 1 as the first evect. Then we see that there is no 2 in q, so we have a zero, Then we have 3 in q and that does exist, so we take Mod[2, 2] = 0 as the value in the evect. Then, there is no 61, so we have a zero. Thus, the first vector is {1, 0, 0, 0}. (The values in this vector are either zero if the value in the first position of the submatrix doesn't exist, otherwise we take the Mod[*, 2] of the second value for the value in the vector). I hope that makes sense. We then look at he second submatrix in q and it contains as the first value of each submatrix, so we can take Mod[*, 2] of each second value and get {1, 1, 0, 1}. The tird would be {0, 0, 0, 1}. And so on (as q could be larger). Thus, the vect[a, q] will return (in this example): {{1, 0, 0, 0}, {1, 1, 0, 1}, {0, 0, 0, 1}} The length of a varies and the length of q varies. We could have a = {-1, 2} and q = {{{-1, 1},{2, 3}, {5, 6}, {7, 8}}, {{-1, 1}, {3, 2}}}, for example. I tried doing this, but made a mess of things. Can someone provide such a module? Thank you, Flip To email me remove "_alpha".