# [ncl-talk] Time interpolation problem, annual to monthly

Mon Feb 5 15:44:32 MST 2018

```Hi Hyacinth,
Are your x&time and y&time arrays in the same range? The following worked
for me:
x = (/1,2,3./)
x!0 = "time"
x&time = (/1980.5,1981.5,1982.5/)

time2 = yyyymm_time(1980,1982,"float")
time3 = yyyymm_to_yyyyfrac(time2,0)   ; creating time in units of fraction
to match x&time
xNew = linint1(x&time,x,False,time3,0)
print(xNew)

Variable: xNew
Type: float
Total Size: 144 bytes
36 values
Number of Dimensions: 1
Dimensions and sizes: [36]
Coordinates:
Number Of Attributes: 1
_FillValue : 9.96921e+36
(0) 9.96921e+36
(1) 9.96921e+36
(2) 9.96921e+36
(3) 9.96921e+36
(4) 9.96921e+36
(5) 9.96921e+36
(6) 1
(7) 1.083374
(8) 1.166626
(9) 1.25
(10) 1.333374
(11) 1.416626
(12) 1.5
(13) 1.583374
(14) 1.666626
(15) 1.75
(16) 1.833374
(17) 1.916626
(18) 2
(19) 2.083374
(20) 2.166626
(21) 2.25
(22) 2.333374
(23) 2.416626
(24) 2.5
(25) 2.583374
(26) 2.666626
(27) 2.75
(28) 2.833374
(29) 2.916626
(30) 3
(31) 9.96921e+36
(32) 9.96921e+36
(33) 9.96921e+36
(34) 9.96921e+36
(35) 9.96921e+36

Hope that helps. If not, or if you have further questions please respond to
the ncl-talk email list only.

On Mon, Feb 5, 2018 at 11:49 AM, Hyacinth Nnamchi <hyacinth.1 at hotmail.com>
wrote:

> Hi NLCers,
>
>
> I have an annual time series I want to re-interpolate to monthly values. I
> do this and get the correct size but everything is missing (and setting the
> @_FillValue and @missingvalue doesn't change result).
>
>
> x  is an annual time series, 80 years
>
> y is a monthly time series, 80 years (i.e. 80 x 12 months)
>
>
> xNew   = linint1_n(x&time,x,False,y&time,0,0)
>
>
> This new time series (xNew) contains all missing values (monthly, 80
> years). Defining x&time and y&time outside the equation doesn't change the
> result.
>
>
> Does anyone know why I'm having the wrong values?
>
>
>
>
> Hyacinth
>
>
>
>
>
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