Re: octave and postgres examples

[Olaf Till]

On Wed, Jun 19, 2013 at 04:36:10PM -0400, Thomas Grzybowski wrote:
> <snip>
> I could really use some examples of reading and writing tables to
> and from octave arrays.  If anyone could post some example code that
> would be very much appreciated.

octave:2> conn = pq_connect (setdbopts ("dbname", "test"));
octave:4> pq_exec_params (conn, "create table octave_array (a float8, b float8, 
c float8);")
ans = 0
octave:5> array = reshape (linspace (0, 1, 12), 4, 3)
array =

   0.00000   0.36364   0.72727
   0.09091   0.45455   0.81818
   0.18182   0.54545   0.90909
   0.27273   0.63636   1.00000

octave:6> pq_exec_params (conn, "copy octave_array from stdin with binary;", 
setdbopts ("copy_in_from_variable", true, "copy_in_data", num2cell (array)))
octave:7> table = pq_exec_params (conn, "select * from octave_array;");
octave:9> cell2mat (table.data)
ans =

   0.00000   0.36364   0.72727
   0.09091   0.45455   0.81818
   0.18182   0.54545   0.90909
   0.27273   0.63636   1.00000

octave:10> table.columns
ans = 
{
  [1,1] = a
  [1,2] = b
  [1,3] = c
}
octave:11> pq_exec_params (conn, "drop table octave_array;")
ans = 0
octave:12> pq_close (conn)

Olaf

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