# Tagged Questions

1answer
87 views

### Bug in GeneratingFunction?

According to the documentation GeneratingFunction[a[n],n,x]==Sum[a[n]x^n,{n,0,Infinity}] However, for $a_n=1/(n+2)$ I obtain ...
0answers
75 views

### Det and MatrixRank freezes on SparseArray with nonzero default value

Why does the following simple code never come to an end (at least with version 8) n = 5; mat = SparseArray[{i_, i_} -> 1, {n, n}, -1/(n - 1)]; MatrixRank[mat] ...
2answers
366 views

### Problem importing URL with Greek characters

I'm considering buying a car. So I thought why not make a web-crawler in Mathematica to pile-up car data? Brilliant idea. Then I found this Greek website, gocar.gr, which just so happens to have all ...
2answers
416 views

### Problem with ContourPlot3D

The following line works fine: ...
0answers
92 views

### An recurrence equation that can be solved in version 7 but not in version 8

A friend of mine showed me this code sample: RSolve[{a[n] == a[n - 5] + 1, Sequence @@ Table[a[i] == 1, {i, 5}]}, a[n], n] // Timing It's solved by version 7 in ...
1answer
146 views

### Version 7 and 8, different behavior of NSolve. Is it reproducible?

I noticed the following difference, and I wonder if it's a problem of my system or the results difference is actually due to the two different versions ...
2answers
429 views

### backward compatibility

When producing or enhancing code, it is tempting to use recent new primitives of Mathematica introduced in version 7 and 8, but for library code or in preparation or future version change in ...
0answers
227 views

### NullSpace[_, Method->“OneStepRowReduction”] is sometimes wrong; how can I work out when this happens?

(This is on MMA 7.0.1.0 on OS X) I've just found a large matrix m for which NullSpace[m] and ...