[SciPy-User] UnivariateSpline returning NaN

[Kevin Gullikson]

Hi all,

I am having a weird issue with UnivariateSpline return nan when trying to
interpolate some data. I have had this happen before a couple times, but it
was always because a nan was in the input arrays. Here, they are all real
numbers. Here is some minimal code that recreates my problem:

import numpy
x,y = numpy.loadtxt("test.out", usecols=(0,1), unpack=True)
from scipy.interpolate import UnivariateSpline
fcn = UnivariateSpline(x,y,s=0)
print fcn(numpy.median(x))

(the result of the print is nan)


Here is the data that I used:

960.38174     2218580.3     2205540
960.3904     2209433.1     2205465.9
960.39906     2202205.2     2205391.9
960.40773     2209385.9     2205317.8
960.41639     2218550.3     2205243.7
960.42505     2220656.8     2205169.7
960.43372     2220779.4     2205095.6
960.44238     2220771.8     2205021.5
960.45104     2220764.3     2204947.5
960.67545     2220409.5     2203030.8
960.68725     2220387.5     2202930.1
960.69905     2220365.5     2202829.5
960.71085     2220343.4     2202728.8
960.72265     2220321.4     2202628.2
960.73445     2220299.3     2202527.6
960.74625     2220277.3     2202427
960.75805     2220222.8     2202326.4
960.76985     2220200.7     2202225.7
960.78165     2220178.7     2202125.2
960.79345     2220156.6     2202024.6
960.80525     2220134.6     2201924
960.81705     2220080.1     2201823.4
961.16055     2219013.1     2198897.2
961.16699     2218983.4     2198842.3
961.17344     2218953.6     2198787.4
961.17988     2218923.8     2198732.5
961.18788     2218886.9     2198664.3
961.19587     2218882.5     2198596.2
961.20386     2218910.5     2198528.1
961.21186     2218906.1     2198459.9
961.21963     2218837.8     2198393.7
961.2274     2218769.4     2198327.4
961.23517     2218701.1     2198261.2
961.24294     2218697.7     2198194.9
961.25071     2218661.8     2198128.7
961.25695     2218633     2198075.6
961.26317     2218604.3     2198022.5
961.27485     2218550.4     2197922.9
961.28653     2218496.5     2197823.4
961.2982     2218475     2197723.8
961.30988     2218421.1     2197624.3
961.32156     2218367.3     2197524.8
961.75259     2216379.3     2193857.4
961.75259     2225525.5     2193857.4
962.04986     2222983.5     2191338.5
962.05175     2222942.3     2191322.5
962.69908     2217396.7     2185841.9
962.71837     2217210.7     2185678.5
962.73766     2217024.8     2185515.2
962.75695     2214605.6     2185352
962.77624     2180663.5     2185188.7
962.79552     2080767.6     2185025.6
962.81481     2027222.1     2184862.4
962.83411     2080471.4     2184699.3
962.8534     2180022.7     2184536.2
962.87269     2213620.2     2184373.1



Thanks,

Kevin Gullikson
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