dataspace1d¶
- sherpa.astro.ui.dataspace1d(start, stop, step=1, numbins=None, id=None, bkg_id=None, dstype=<class 'sherpa.data.Data1DInt'>)¶
Create the independent axis for a 1D data set.
Create an “empty” one-dimensional data set by defining the grid on which the points are defined (the independent axis). The values are set to 0.
- Parameters
start (number) – The minimum value of the axis.
stop (number) – The maximum value of the axis.
step (number, optional) – The separation between each grid point. This is not used if
numbins
is set.numbins (int, optional) – The number of grid points. This over-rides the
step
setting.id (int or str, optional) – The identifier for the data set to use. If not given then the default identifier is used, as returned by
get_default_id
.bkg_id (int or str, optional) – If set, the grid is for the background component of the data set.
dstype (data class to use, optional) – What type of data is to be used. Supported values include
Data1DInt
(the default),Data1D
, andDataPHA
.
See also
dataspace2d
Create the independent axis for a 2D data set.
get_dep
Return the dependent axis of a data set.
get_indep
Return the independent axes of a data set.
set_dep
Set the dependent axis of a data set.
Notes
The meaning of the
stop
parameter depends on whether it is a binned or unbinned data set (as set by thedstype
parameter).Examples
Create a binned data set, starting at 1 and with a bin-width of 1.
>>> dataspace1d(1, 5, 1) >>> print(get_indep()) (array([ 1., 2., 3., 4.]), array([ 2., 3., 4., 5.]))
This time for an un-binned data set:
>>> dataspace1d(1, 5, 1, dstype=Data1D) >>> print(get_indep()) (array([ 1., 2., 3., 4., 5.]),)
Specify the number of bins rather than the grid spacing:
>>> dataspace1d(1, 5, numbins=5, id=2) >>> (xlo, xhi) = get_indep(2) >>> xlo array([ 1. , 1.8, 2.6, 3.4, 4.2]) >>> xhi array([ 1.8, 2.6, 3.4, 4.2, 5. ])
>>> dataspace1d(1, 5, numbins=5, id=3, dstype=Data1D) >>> (x, ) = get_indep(3) >>> x array([ 1., 2., 3., 4., 5.])
Create a grid for a PHA data set called ‘jet’, and for its background component:
>>> dataspace1d(0.01, 11, 0.01, id='jet', dstype=DataPHA) >>> dataspace1d(0.01, 11, 0.01, id='jet', bkg_id=1, ... dstype=DataPHA)