def get_signature(self, spectrumID):
'''Returns a spectrum with some additional metadata.
Usage::
sig = aster.get_signature(spectrumID)
Arguments:
`spectrumID` (int):
The **SpectrumID** value for the desired spectrum from the
**Spectra** table in the database.
Returns:
`sig` (:class:`~spectral.database.aster.Signature`):
An object with the following attributes:
============== ===== ========================================
Attribute Type Description
============== ===== ========================================
measurement_id int SpectrumID value from Spectra table
sample_name str **Sample** from the **Samples** table
sample_id int **SampleID** from the **Samples** table
x list list of band center wavelengths
y list list of spectrum values for each band
============== ===== ========================================
'''
import array
# Retrieve spectrum from Spectra table
query = '''SELECT Samples.Name, Samples.SampleID, XData, YData
FROM Samples, Spectra WHERE Samples.SampleID = Spectra.SampleID
AND Spectra.SpectrumID = ?'''
result = self.cursor.execute(query, (spectrumID, ))
results = result.fetchall()
if len(results) < 1:
raise "Measurement record not found"
sig = Signature()
sig.measurement_id = spectrumID
sig.sample_name = results[0][0]
sig.sample_id = results[0][1]
x = array.array(arraytypecode)
frombytes(x, results[0][2])
sig.x = list(x)
y = array.array(arraytypecode)
frombytes(y, results[0][3])
sig.y = list(y)
return sig
def get_spectrum(self, spectrumID):
'''Returns a spectrum from the database.
Usage:
(x, y) = aster.get_spectrum(spectrumID)
Arguments:
`spectrumID` (int):
The **SpectrumID** value for the desired spectrum from the
**Spectra** table in the database.
Returns:
`x` (list):
Band centers for the spectrum.
`y` (list):
Spectrum data values for each band.
Returns a pair of vectors containing the wavelengths and measured
values values of a measurment. For additional metadata, call
"get_signature" instead.
'''
import array
query = '''SELECT XData, YData FROM Spectra WHERE SpectrumID = ?'''
result = self.cursor.execute(query, (spectrumID, ))
rows = result.fetchall()
if len(rows) < 1:
raise 'Measurement record not found'
x = array.array(arraytypecode)
frombytes(x, rows[0][0])
y = array.array(arraytypecode)
frombytes(y, rows[0][1])
return (list(x), list(y))
def array_from_blob(blob):
a = array.array(arraytypecode)
frombytes(a, blob)
return a