spacepy.toolbox.interpol

spacepy.toolbox.interpol(newx, x, y, wrap=None, **kwargs)[source]

1-D linear interpolation with interpolation of hours/longitude

Parameters
newxarray_like

x values where we want the interpolated values

xarray_like

x values of the original data (must be monotonically increasing or wrapping)

yarray_like

y values of the original data

wrapstring, optional

for continuous x data that wraps in y at ‘hours’ (24), ‘longitude’ (360), or arbitrary value (int, float)

kwargsdict

additional keywords, currently accepts baddata that sets baddata for masked arrays

Returns
outnumpy.masked_array

interpolated data values for new abscissa values

Examples

For a simple interpolation

>>> import spacepy.toolbox as tb
>>> import numpy
>>> x = numpy.arange(10)
>>> y = numpy.arange(10)
>>> tb.interpol(numpy.arange(5)+0.5, x, y)
array([ 0.5,  1.5,  2.5,  3.5,  4.5])

To use the wrap functionality, without the wrap keyword you get the wrong answer

>>> y = range(24)*2
>>> x = range(len(y))
>>> tb.interpol([1.5, 10.5, 23.5], x, y, wrap='hour').compressed() # compress removed the masked array
array([  1.5,  10.5,  23.5])
>>> tb.interpol([1.5, 10.5, 23.5], x, y)
array([  1.5,  10.5,  11.5])