(use-modules (charting))

(define (observations->data observations)
  (define (mean l)
    (/ (apply + l) (length l)))
  (define (stddev l)
    (let ((xbar (mean l)))
      (sqrt (mean (map (lambda (x) (expt (- x xbar) 2)) l)))))
  (map
   (lambda (group)
     (cons
      (car group)
      (map
       (lambda (observation)
         (let ((tbar (mean (cddr observation))))
           `(,tbar ,(car observation)
                   (#:y-bracket ,(stddev (cddr observation))))))
       (cdr group))))
   observations))

;; Hint: export TIMEFORMAT='%3R'
(define *observations*
  '(("Initialization"
     ("Python 2.5.1c1"
      "for i in `seq 10`; do time python -c 1; done"
      0.075
      0.073
      0.073
      0.073
      0.072
      0.074
      0.071
      0.081
      0.072
      0.073)
     ("SCM 5e3"
      #f
      0.099
      0.099
      0.098
      0.100
      0.097
      0.101
      0.096
      0.096
      0.098
      0.106)
     ("Guile 1.6.8"
      "for i in `seq 10`; do time guile -c 1; done"
      0.082
      0.082
      0.082
      0.081
      0.081
      0.088
      0.080
      0.082
      0.081
      0.083)
     ("Guile 1.8 CVS"
      ;; with Ludovic's module lookup patch, CFLAGS=-g -O2
      "for i in `seq 10`; do time guile -c 1; done"
      0.143
      0.141
      0.139
      0.139
      0.138
      0.140
      0.148
      0.147
      0.149
      0.160)
     ("Guile 1.8 CVS with TLS"
      "for i in `seq 10`; do time guile -c 1; done"
      0.131
      0.126
      0.126
      0.124
      0.123
      0.123
      0.137
      0.123
      0.124
      0.121)
     )
    ("(use-modules (oop goops))"
     ("Guile 1.6.8"
      "for i in `seq 10`; do time guile -c '(use-modules (oop goops))'; done"
      0.137
      0.136
      0.130
      0.133
      0.131
      0.131
      0.142
      0.151
      0.135
      0.131
      )
     ("Guile 1.8 CVS"
      "for i in `seq 10`; do time guile -c '(use-modules (oop goops))'; done"
      0.260
      0.263
      0.256
      0.252
      0.274
      0.289
      0.274
      0.280
      0.324
      0.294)

     ("Guile 1.8 CVS with TLS"
      "for i in `seq 10`; do time guile -c '(use-modules (oop goops))'; done"
      0.244
      0.242
      0.261
      0.245
      0.244
      0.243
      0.275
      0.272
      0.269
      0.275))))

(make-bar-chart "Guile Benchmarks" (observations->data *observations*)
                :write-to-png "/tmp/guile-benchmarks.png"
                :bar-width 40 :group-spacing 40 :chart-height 240
                :bar-value-format "~f"
                :chart-params '(:y-axis-label "Wall-clock execution time (s)"))