AHELP for CIAO 4.13 Sherpa v1

# create_arf

Context: data

Create an ARF.

## Syntax

```create_arf(elo, ehi, specresp=None, exposure=None, ethresh=None,
name='test-arf')

elo - numpy.ndarray
ehi - numpy.ndarray
specresp - None or array, optional
exposure - number or None, optional
ethresh - number or None, optional
name - str, optional```

## Examples

### Example 1

Create a flat ARF, with a value of 1.0 cm^2 for each bin, over the energy range 0.1 to 10 keV, with a bin spacing of 0.01 keV.

```>>> egrid = np.arange(0.1, 10, 0.01)
>>> arf = create_arf(egrid[:-1], egrid[1:])```

### Example 2

Create an ARF that has 10 percent more area than the ARF from the default data set:

```>>> arf1 = get_arf()
>>> elo = arf1.energ_lo
>>> ehi = arf1.energ_hi
>>> y = 1.1 * arf1.specresp
>>> arf2 = create_arf(elo, ehi, y, exposure=arf1.exposure)```

### PARAMETERS

The parameters for this function are:

Parameter Definition
elo The energy bins (low and high, in keV) for the ARF. It is assumed that ehi_i > elo_i, elo_j > 0, the energy bins are either ascending - so elo_i+1 > elo_i - or descending (elo_i+1 < elo_i), and that there are no overlaps.
ehi The energy bins (low and high, in keV) for the ARF. It is assumed that ehi_i > elo_i, elo_j > 0, the energy bins are either ascending - so elo_i+1 > elo_i - or descending (elo_i+1 < elo_i), and that there are no overlaps.
specresp The spectral response (in cm^2) for the ARF. It is assumed to be >= 0. If not given a flat response of 1.0 is used.
exposure If not None, the exposure of the ARF in seconds.
ethresh Passed through to the DataARF call. It controls whether zero-energy bins are replaced.
name The name of the ARF data set