    Create the independent axis for a 1D data set.

dataspace1d(start, stop, step=1, numbins=None, id=None, bkg_id=None, dstype=Data1DInt)
start - number
stop - number
step - number, optional
numbins - int, optional
id - int or str, optional
bkg_id - int or str, optional
dstype - data class to use, optional

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.

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 (note that the axis values are in channels, and there are 1024 channels set):

>>> dataspace1d(1, 1024, id='jet', dstype=DataPHA) >>> dataspace1d(1, 1024, id='jet', bkg_id=1, dstype=DataPHA)

PARAMETERS

The parameters for this function are:

Parameter
Definition
start
The minimum value of the axis.
stop
The maximum value of the axis.
step
The separation between each grid point. This is not used if

numbins is set.
numbins
The number of grid points. This over-rides the step

setting.
id
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
If set, the grid is for the background component of the data set.
dstype
What type of data is to be used. Supported values include

`Data1DInt` (the default), `Data1D` , and `DataPHA` .

Notes

The meaning of the stop parameter depends on whether it is a binned or unbinned data set (as set by the dstype

parameter).

See the bugs pages on the Sherpa website for an up-to-date listing of known bugs.

December 2023