Package astLib :: Module astSED :: Class Passband
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Class Passband

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Known Subclasses:

This class describes a filter transmission curve. Passband objects are created by loading data from from text files containing wavelength in angstroms in the first column, relative transmission efficiency in the second column (whitespace delimited). For example, to create a Passband object for the 2MASS J filter:

passband=astSED.Passband("J_2MASS.res")

where "J_2MASS.res" is a file in the current working directory that describes the filter.

Wavelength units can be specified as 'angstroms', 'nanometres' or 'microns'; if either of the latter, they will be converted to angstroms.

Instance Methods [hide private]
 
__init__(self, fileName, normalise=True, inputUnits='angstroms', wavelengthColumn=0, transmissionColumn=1) source code
list
asList(self)
Returns a two dimensional list of [wavelength, transmission], suitable for plotting by gnuplot.
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rescale(self, maxTransmission)
Rescales the passband so that maximum value of the transmission is equal to maxTransmission.
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plot(self, xmin='min', xmax='max', maxTransmission=None)
Plots the passband, rescaling the maximum of the tranmission curve to maxTransmission if required.
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float
effectiveWavelength(self)
Calculates effective wavelength for the passband.
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Method Details [hide private]

asList(self)

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Returns a two dimensional list of [wavelength, transmission], suitable for plotting by gnuplot.

Returns: list
list in format [wavelength, transmission]

rescale(self, maxTransmission)

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Rescales the passband so that maximum value of the transmission is equal to maxTransmission. Useful for plotting.

Parameters:
  • maxTransmission (float) - maximum value of rescaled transmission curve

plot(self, xmin='min', xmax='max', maxTransmission=None)

source code 

Plots the passband, rescaling the maximum of the tranmission curve to maxTransmission if required.

Parameters:
  • xmin (float or 'min') - minimum of the wavelength range of the plot
  • xmax (float or 'max') - maximum of the wavelength range of the plot
  • maxTransmission (float) - maximum value of rescaled transmission curve

effectiveWavelength(self)

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Calculates effective wavelength for the passband. This is the same as equation (3) of Carter et al. 2009.

Returns: float
effective wavelength of the passband, in Angstroms