Compute temperature autocorrelation graphs

20221216.temperature-autocorell

## Get data from https://zenodo.org/record/6961511#.Y4-HhqIo9hE
## in era-nuts-t2m.zip we want era-nuts-t2m-nuts0-daily-singleindex.csv

perl -F',' -ne 'next if $F[0]=~m/time/; die unless $F[0]=~m/^\"([0-9]{4})\/([0-9]{2})\/([0-9]{2}) ([0-9]{2})\:([0-9]{2})\:([0-9]{2})\"$/; print "$1-$2-$3T$4:$5:$6Z\t$F[14]\n"' era-nuts-t2m-nuts0-daily-singleindex.csv > /tmp/temp-fr-daily.dat

: > /tmp/temp-fr-autocorrels.dat ; for i in $(seq 0 400) ; do
    echo "$i days"
    ifmt=$(printf %03d $i)
    ip1=$((i+1))
    paste /tmp/temp-fr-daily.dat <(tail +$ip1 /tmp/temp-fr-daily.dat) > /tmp/temp-fr-shifted.dat
    (echo 'set terminal pngcairo size 800,600' ; echo 'set output "/tmp/temp-fr-autocorrel-'"$ifmt"'days.png"' ; echo 'stats "/tmp/temp-fr-shifted.dat" using ($2):($4) name "st"' ; echo 'w(x)=st_intercept+st_slope*x' ; echo 'regrtitle=sprintf("[r=%s%.4f]", (st_correlation<0?"−":""), abs(st_correlation))' ; echo 'set title "Distribution de températures en France à '"$i"' jours d'\''écart {/*0.5 (1980–2021)}"' ; echo 'set xlabel "Température jour J"' ; echo 'set ylabel "Température jour J+'"$i"'"' ; echo 'set key bottom right' ; echo 'plot [st_min_x:st_max_x] [st_min_x:st_max_x] "/tmp/temp-fr-shifted.dat" using ($2):($4) pt 7 lc rgb "#000080" ps 0.1 notitle, [x=st_min_x:st_max_x] w(x) lc rgb "#ff0080" title regrtitle' ; echo 'set print "/tmp/temp-fr-autocorrels.dat" append' ; echo 'print sprintf("%d%c%.6f", '"$i"', 9, st_correlation)') | gnuplot
done

(echo 'set terminal pngcairo size 800,600' ; echo 'set output "/tmp/temp-fr-autocorrels.png"' ; echo 'set title "Autocorrélation de la température moyenne en France {/*0.5 (1980–2021)}"' ; echo 'set xlabel "Nombre de jours d'\''écart"' ; echo 'set ylabel "Coefficient de corrélation (r)"' ; echo 'set key bottom right' ; echo 'plot [0:400] "/tmp/temp-fr-autocorrels.dat" with lines title "autocorrélation"') | gnuplot

(echo 'set terminal pngcairo size 800,600' ; echo 'set output "/tmp/temp-fr-autocorrels-short.png"' ; echo 'set title "Autocorrélation de la température moyenne en France {/*0.5 (1980–2021)}"' ; echo 'set xlabel "Nombre de jours d'\''écart"' ; echo 'set ylabel "Coefficient de corrélation (r)"' ; echo 'set key bottom right' ; echo 'plot [0:20] "/tmp/temp-fr-autocorrels.dat" with lines title "autocorrélation"') | gnuplot

See https://twitter.com/gro_tsen/status/1603808798157709313 for context.