[Numpy-discussion] bug in array instanciation?

2012-01-27 Thread Emmanuel Mayssat 
In [20]: dt_knobs =
[('pvName',(str,40)),('start','float'),('stop','float'),('mode',(str,10))]

In [21]: r_knobs = np.recarray([],dtype=dt_knobs)

In [22]: r_knobs
Out[22]:
rec.array(('\xa0\x8c\xc9\x02\x00\x00\x00\x00(\xc8v\x02\x00\x00\x00\x00\x00\xd3\x86\x02\x00\x00\x00\x00\x10\xdeJ\x02\x00\x00\x00\x00\x906\xb9\x02',
1.63e-322, 1.351330465085e-312, '\x90\xc6\xa3\x02\x00\x00\x00\x00P'),
  dtype=[('pvName', '|S40'), ('start', 'f8'), ('stop', 'f8'),
('mode', '|S10')])

why is the array not empty?
--
E
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[Numpy-discussion] array metadata

2012-01-25 Thread Emmanuel Mayssat 
Is there a way to store metadata for an array?
For example, date the samples were collected, name of the operator, etc.

Regards,
--
Emmanuel
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[Numpy-discussion] Saving and loading a structured array from a TEXT file

2012-01-23 Thread Emmanuel Mayssat 
Is there a way to save a structured array in a text file?
My problem is not so much in the saving procedure, but rather in the
'reloading' procedure.
See below


In [3]: import numpy as np

In [4]: r = np.ones(3,dtype=[('name', '|S5'), ('foo', 'i8'), ('bar', 'f8')])

In [5]: r.tofile('toto.txt',sep='\n')

bash-4.2$ cat toto.txt
('1', 1, 1.0)
('1', 1, 1.0)
('1', 1, 1.0)

In [7]: r2 = np.fromfile('toto.txt',sep='\n',dtype=r.dtype)
---
ValueErrorTraceback (most recent call last)
/home/cls1fs/clseng/10/ipython-input-7-b07ba265ede7 in module()
 1 r2 = np.fromfile('toto.txt',sep='\n',dtype=r.dtype)

ValueError: Unable to read character files of that array type


--
Emmanuel
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[Numpy-discussion] 'Advanced' save and restore operation

2012-01-23 Thread Emmanuel Mayssat 
After having saved data, I need to know/remember the data dtype to
restore it correctly.
Is there a way to save the dtype with the data?
(I guess the header parameter of savedata could help, but they are
only available in v2.0+ )

I would like to save several related structured array and a dictionary
of parameters into a TEXT file.
Is there an easy way to do that?
(maybe xml file, or maybe archive zip file of other files, or . )

Any recommendation is helpful.

Regards,
--
Emmanuel
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