Made plots in plot' and math' render nicely in PDFs (plots in docs are picts now)

Fixed errors in `linear-seq' when end <= start

collects/math/scribblings/utils.rkt

@@ -33,6 +33,6 @@
   (define eval (make-base-eval))
   (eval '(require math))
   (eval '(require (rename-in (except-in plot plot plot3d)
-                             [plot-bitmap  plot]
-                             [plot3d-bitmap  plot3d])))
+                             [plot-pict  plot]
+                             [plot3d-pict  plot3d])))
   eval)

collects/plot/common/sample.rkt

@@ -28,6 +28,8 @@
     [(zero? num)  empty]
     ; ambiguous request: arbitrarily return start
     [(and start? end? (= 1 num))  (list start)]
+    [(end . < . start)  (reverse (linear-seq end start num #:start? end? #:end? start?))]
+    [(end . = . start)  (build-list num (λ _ start))]
     [else
      (define size (- end start))
      (define step (/ size (cond [(and start? end?)  (- num 1)]

collects/plot/scribblings/common.rkt

@@ -34,8 +34,8 @@
     (eval '(begin
              (require racket/math racket/match racket/list racket/draw racket/class
                       (rename-in (except-in plot plot plot3d)
-                                 [plot-bitmap  plot]
-                                 [plot3d-bitmap  plot3d])
+                                 [plot-pict  plot]
+                                 [plot3d-pict  plot3d])
                       plot/utils)))
     eval))
 

collects/plot/scribblings/intro.scrbl

@@ -108,11 +108,19 @@ In both cases, @(racket plot) and @(racket function-interval) work together to d
 It is not always possible for renderers and @(racket plot) or @(racket plot3d) to determine the bounds:
 
 @interaction[#:eval plot-eval
+                    (eval:alts
                      (plot (function sqr))
+                     (eval:result "" "" "plot: could not determine sensible plot bounds; got x ∈ [#f,#f], y ∈ [#f,#f]"))
+                    (eval:alts
                      (plot (function sqr #f #f))
+                     (eval:result "" "" "plot: could not determine sensible plot bounds; got x ∈ [#f,#f], y ∈ [#f,#f]"))
+                    (eval:alts
                      (plot (function sqr (- pi)))
+                     (eval:result "" "" "plot: could not determine sensible plot bounds; got x ∈ [-3.141592653589793,#f], y ∈ [#f,#f]"))
+                    (eval:alts
                      (plot (list (function sqr #f 0)
-                                (function sqr 0 #f)))]
+                                 (function sqr 0 #f)))
+                     (eval:result "" "" "plot: could not determine sensible plot bounds; got x ∈ [0,0], y ∈ [0,0]"))]
 
 There is a difference between passing bounds to renderers and passing bounds to @(racket plot) or @(racket plot3d): bounds passed to @(racket plot) or @(racket plot3d) cannot be changed by a renderer that requests different bounds.
 We might say that bounds passed to renderers are @italic{suggestions}, and bounds passed to @(racket plot) and @(racket plot3d) are @italic{commandments}.

collects/plot/scribblings/porting.scrbl

@@ -52,7 +52,10 @@ The safest way to ensure that @(racket plot) can determine bounds for the plot a
 
 Because PLoT is now smarter about choosing bounds, there are better ways. For example, suppose you have
 
-@interaction[#:eval plot-eval (plot (line sin))]
+@interaction[#:eval plot-eval
+                    (eval:alts
+                     (plot (line sin))
+                     (eval:result "" "" "plot: could not determine sensible plot bounds; got x ∈ [#f,#f], y ∈ [#f,#f]"))]
 
 You could either change it to
 

collects/plot/scribblings/ticks.scrbl

@@ -50,8 +50,10 @@ A log transform. Use this to generate plots with log-scale axes. Any such axis m
 
 The beginning of the @secref["ticks and transforms"] section has a working example. An example of exceeding the bounds is
 @interaction[#:eval plot-eval
+                    (eval:alts
                      (parameterize ([plot-x-transform  log-transform])
-                      (plot (function (λ (x) x) -1 1)))]
+                       (plot (function (λ (x) x) -1 1)))
+                     (eval:result "" "" "log-transform: expects type <positive real> as 1st argument, given: -1; other arguments were: 1"))]
 See @racket[axis-transform-bound] and @racket[axis-transform-append] for ways to get around an axis transform's bounds limitations.
 }
 

collects/plot/tests/low-level-tests.rkt

@@ -17,10 +17,15 @@
                   int-str->e-str frac-str->e-str)
          plot/common/worker-thread)
 
+(check-equal? (linear-seq 1 1 2) '(1 1))
 (check-equal? (linear-seq 0 1 2 #:start? #t #:end? #t) '(0 1))
 (check-equal? (linear-seq 0 1 2 #:start? #t #:end? #f) '(0 2/3))
 (check-equal? (linear-seq 0 1 2 #:start? #f #:end? #t) '(1/3 1))
 (check-equal? (linear-seq 0 1 2 #:start? #f #:end? #f) '(1/4 3/4))
+(check-equal? (linear-seq 1 0 2 #:start? #t #:end? #t) '(1 0))
+(check-equal? (linear-seq 1 0 2 #:start? #t #:end? #f) '(1 1/3))
+(check-equal? (linear-seq 1 0 2 #:start? #f #:end? #t) '(2/3 0))
+(check-equal? (linear-seq 1 0 2 #:start? #f #:end? #f) '(3/4 1/4))
 
 (check-exn exn:fail:contract?
            (λ () (vector-field (λ (v [z 0]) v) -4 4 -4 4))