Pulling arrays from database for plotting

[Kurt Schwehr]

Hi all,

What's the best way to pull arrays from a database for plotting?
Right now, this is what I do, but can it be done simpler / more
efficiently?

ipython -pylab
import sqlite3
cx = sqlite3.connect('20080407.decimated.db3')
a = array( [tuple(row) for row in cx.execute('SELECT cg_offset,
delta_t_sec FROM bs_time WHERE recvr=2;')] )
x = a[:,0]
y = a[:,1]
plot(x,y)

However, if I try to plot it directly using transpose, it hangs:

import sqlite3
cx = sqlite3.connect('20080407.decimated.db3')
plot(array( [tuple(row) for row in cx.execute('SELECT cg_offset,
delta_t_sec FROM bs_time WHERE recvr=2;')] ).transpose())

It is that plot just doesn't know what to do with a 2D array?  Then I
tried this and it works, but is long and confusing to the uninitiated.

plot(*array( [tuple(row) for row in cx.execute('SELECT cg_offset,
delta_t_sec FROM bs_time WHERE recvr=2;')] ).T)



In [4]: a
Out[4]:
array([[  2.40000000e+01,   0.00000000e+00],
       [  2.50000000e+01,  -1.00000000e+00],
       [  3.40000000e+01,   0.00000000e+00],
       ...,
       [  8.63840000e+04,   2.00000000e+01],
       [  8.63940000e+04,   2.00000000e+01],
       [  8.64040000e+04,   2.00000000e+01]])

In [5]: a.transpose()
Out[5]:
array([[  2.40000000e+01,   2.50000000e+01,   3.40000000e+01, ...,
          8.63840000e+04,   8.63940000e+04,   8.64040000e+04],
       [  0.00000000e+00,  -1.00000000e+00,   0.00000000e+00, ...,
          2.00000000e+01,   2.00000000e+01,   2.00000000e+01]])