astLib.astSED.Passband

Package astLib :: Module astSED :: Class Passband |
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[frames] | no frames]

# Class Passband

source code

Known Subclasses:
  - TopHatPassband

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. | source code
rescale(self, maxTransmission) Rescales the passband so that maximum value of the transmission is equal to maxTransmission. | source code
plot(self, xmin=`'``min``'`, xmax=`'``max``'`, maxTransmission=None) Plots the passband, rescaling the maximum of the tranmission curve to maxTransmission if required. | source code
float |
effectiveWavelength(self) Calculates effective wavelength for the passband. | source code

Method Details | [hide private]

### asList(self) | source code
Returns a two dimensional list of [wavelength, transmission], suitable for plotting by gnuplot. Returns: list list in format [wavelength, transmission]

### rescale(self, maxTransmission) | source code
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) | source code
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