ledger -> gnuplot with monthly cumulatives

---

food.gnuplot

# == Setup ==
set terminal qt
set xdata time
set timefmt "%Y/%m/%d"

set label "COVID" at "2020/03/20",850

set key on left top vertical enhanced title "Categories"
set title "Food Expenses"

set offsets -328725, 0, 0, 0

# == Monthly-Bucketed Expenses ==
plot \
  "monthly_expenses/food_groceries.txt" using 1:2 title "Groceries" with fillsteps, \
  "monthly_expenses/food_in.txt" using 1:2 title "Take-out" with fillsteps,  \
  "monthly_expenses/food_out.txt" using 1:2 title "Eat-out" with fillsteps, \
  "monthly_expenses/food_all.txt" using 1:2 title "Total" with fillsteps

---

get_viz-data.sh

# manufacture zeros at the beginning of each month between START_DATE and END_DATE
BLANKS=mktemp
start_date=$1
end_date=$2
current_date=$(gdate -d "$start_date" "+%Y/%m/01")
while [[ "$current_date" < "$end_date" ]]; do
    echo "$current_date 0.0" >>$BLANKS
    current_date=$(gdate -d "$current_date 1 month" "+%Y/%m/01")
done
echo "$current_date 0.0" >>$BLANKS

ledger --effective -f ledgers/main.ldg reg --sort date -F '%D %t\n' \
    Expenses:Food:Groceries |
    tr -d "$," |
    gawk -F " " -f viz-bucket.awk \
        >$MONTHLY_DIR/food_groceries.txt

ledger --effective -f ledgers/main.ldg reg --sort date -F '%D %t\n' \
    Expenses:Food:Out |
    tr -d "$," |
    awk -F " " -f viz-bucket.awk \
        >$MONTHLY_DIR/food_out.txt

ledger --effective -f ledgers/main.ldg reg --sort date -F '%D %t\n' \
    Expenses:Food:In |
    tr -d "$," |
    awk -F " " -f viz-bucket.awk \
        >$MONTHLY_DIR/food_in.txt

ledger --effective -f ledgers/main.ldg reg --sort date -F '%D %t\n' \
    Expenses:Food |
    tr -d "$," |
    awk -F " " -f viz-bucket.awk \
        >$MONTHLY_DIR/food_all.txt

# merge blanks into monthly expense files (tricky!)
ls $MONTHLY_DIR | xargs -R 2 -I % \
    gsort \
    -k1,1 \
    -s \
    $MONTHLY_DIR/% $BLANKS \
    -o $MONTHLY_DIR/%

# clean up blanks
rm $BLANKS

---

viz-bucket.awk

BEGIN {
    sum=0
    bucket_month=""
} {
    line_date = substr($1, 0, 10)
    line_year = substr(line_date, 0, 4)
    line_month = substr(line_date, 6, 2)
    line_amt = $2

    if (bucket_month == line_month) {
        sum += line_amt
        printf "%s/%s/%s %s\n", line_year, line_month, substr(line_date, 9, 2), sum
    } else {
        sum = line_amt
        bucket_month=line_month
        printf "%s/%s/%s %s\n", line_year, line_month, substr(line_date, 9, 2), sum
    }
}