On Friday, 05 February, 2016 08:38:42 pl...@pi... wrote:
> Hi,
>
> I have fitted an analytic fn to some data using gnuplot and now I want
> to create a synthetic monthly dataset by outputting to "table".
>
> Since gnuplot will always produce a point at start and end of range I
> specify the plot range in integer years and set samples to (years-1)
> *12 +1 to account for the last year in the range just having one datum
> point.
>
>
> plot [1978:2016] cos3(x) * cos2(x)
> set samples (2015-1978)*12+1 # 445
> set table "synth.txt"
> rep
> unset table
>
> This gives the expected number of data lines but the dates are not
> consistent from year to year. There is a small drift in the decimal part
> of the dates.
>
> Only a handful of data lines get an exact beginning of year , ie no
> decimal part:
>
> awk '($1 !~ /[0-9]\./){print}' "synth.txt"
>
> # Curve 0 of 1, 445 points
> # Curve title: "cos3(x) * cos2(x))"
> # x y type
> 1978 -0.801801 i
> 1981 -0.895154 i
> 1994 -0.105538 i
> 1997 -0.733846 i
> 2000 -0.563258 i
> 2013 0.204895 i
> 2016 -0.168844 i
>
>
> On a 200y range it worked as expected. Is there some rounding error
> issue or trick I am missing?
Leap years?
The leap-year cycle is 200 years.
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