Annual Leaf Cycle

# Zoe Phin, 2021/02/13
# File: lai.sh
# To Run: source lai.sh; require; download; fix; animate

require() { sudo apt-get install -y netpbm imagemagick; }

download() {
    list=$(wget -qO- 'https://neo.sci.gsfc.nasa.gov/view.php?datasetId=MOD15A2_M_LAI&date=2016-01-01' | grep '"viewDataset' | cut -f2 -d "'" | tr '\n' ' ')	
    let n=1
    for si in $list; do 
        N=$(printf "%02d" $n)
        wget -O lai$N.jpg "https://neo.sci.gsfc.nasa.gov/servlet/RenderData?si=$si&cs=rgb&format=JPEG&width=750&height=375"
        sleep 1
        let n++
    done
}

fix() { 
    for jpg in `ls -1 lai*.jpg`; do
        pnm=${jpg/.jpg/.pnm}
        echo -e 'P3\n750 375\n255\n' > $pnm
        jpegtopnm $jpg | pnmtoplainpnm | sed 's/  /\n/g' | awk '{printf "%03d %03d %03d ", $1, $2, $3}' | fold -w9000 > .tmp

        cut -c1-300 .tmp > .right
        cut -c300-  .tmp > .left
        paste -d '' .left .right >> $pnm

        pnmtopng $pnm > $jpg
    done
    rm -f *.pnm
}

animate() { convert -delay 25 -loop 0 lai*.jpg animlai.gif; }