- sherpa.utils.get_fwhm(y, x, xhi=None)
Estimate the width of the data.
This is only valid for positive data values (
y (array_like) – The data points. The x array must be in ascending order.
x (array_like) – The data points. The x array must be in ascending order.
xhi (None or array_like, optional) – If given then the x array is taken to be the low-edge of each bin. This is unused.
ans – An estimate of the full-width half-maximum of the peak. If the data is negative, or no edge is found then half the X range is returned.
- Return type:
If there are multiple peaks of the same height then the first peak is used.
The approach is to find the maximum position and then extend out to the first bins which fall below half the height. The difference of the two points is used. If only one side falls below the value then twice this separation is used. If the half-height is not reached then the value is set to be half the width of the x array. In all cases the upper-edge of the x arrays is ignored, if given.