)abbrev domain PLOT Plot
++ Author: Michael Monagan (revised by Clifton J. Williamson)
++ Date Created: Jan 1988
++ Basic Operations: plot, pointPlot, plotPolar, parametric?, zoom, refine,
++ tRange, minPoints, setMinPoints, maxPoints, screenResolution, adaptive?,
++ setAdaptive, numFunEvals, debug
++ Related Constructors:
++ Also See:
++ AMS Classifications:
++ Keywords: plot, function, parametric
++ References:
++ Description: The Plot domain supports plotting of functions defined over a
++ real number system.  A real number system is a model for the real
++ numbers and as such may be an approximation.  For example
++ floating point numbers and infinite continued fractions.
++ The facilities at this point are limited to 2-dimensional plots
++ or either a single function or a parametric function.
Plot() : Exports == Implementation where
  B   ==> Boolean
  F   ==> DoubleFloat
  I   ==> Integer
  L   ==> List
  N   ==> NonNegativeInteger
  OUT ==> OutputForm
  P   ==> Point F
  RN  ==> Fraction Integer
  S   ==> String
  SEG ==> Segment
  R   ==> Segment F
  C   ==> Record(source : F -> P, ranges : L R, knots : L F, points : L P)

  Exports ==> PlottablePlaneCurveCategory with

--% function plots

    plot : (F -> F, R) -> %
      ++ plot(f, a..b) plots the function \spad{f(x)} on the interval \spad{[a, b]}.
    plot : (F -> F, R, R) -> %
      ++ plot(f, a..b, c..d) plots the function \spad{f(x)} on the interval
      ++ \spad{[a, b]}; y-range of \spad{[c, d]} is noted in Plot object.

--% multiple function plots

    plot : (L(F -> F), R) -> %
      ++ plot([f1, ..., fm], a..b) plots the functions \spad{y = f1(x)}, ...,
      ++ \spad{y = fm(x)} on the interval \spad{a..b}.
    plot : (L(F -> F), R, R) -> %
      ++ plot([f1, ..., fm], a..b, c..d) plots the functions \spad{y = f1(x)}, ...,
      ++ \spad{y = fm(x)} on the interval \spad{a..b}; y-range of \spad{[c, d]} is
      ++ noted in Plot object.

--% parametric plots

    plot : (F -> F, F -> F, R) -> %
      ++ plot(f, g, a..b) plots the parametric curve \spad{x = f(t)}, \spad{y = g(t)}
      ++ as t ranges over the interval \spad{[a, b]}.
    plot : (F -> F, F -> F, R, R, R) -> %
      ++ plot(f, g, a..b, c..d, e..f) plots the parametric curve \spad{x = f(t)},
      ++ \spad{y = g(t)} as t ranges over the interval \spad{[a, b]}; x-range
      ++ of \spad{[c, d]} and y-range of \spad{[e, f]} are noted in Plot object.

--% parametric plots

    pointPlot : (F -> P, R) -> %
      ++ pointPlot(t +-> (f(t), g(t)), a..b) plots the parametric curve
      ++ \spad{x = f(t)}, \spad{y = g(t)} as t ranges over the interval \spad{[a, b]}.
    pointPlot : (F -> P, R, R, R) -> %
      ++ pointPlot(t +-> (f(t), g(t)), a..b, c..d, e..f) plots the parametric
      ++ curve \spad{x = f(t)}, \spad{y = g(t)} as t ranges over the interval \spad{[a, b]};
      ++ x-range of \spad{[c, d]} and y-range of \spad{[e, f]} are noted in Plot object.

--% polar plots

    plotPolar : (F -> F, R) -> %
      ++ plotPolar(f, a..b) plots the polar curve \spad{r = f(theta)} as
      ++ theta ranges over the interval \spad{[a, b]}; this is the same as
      ++ the parametric curve \spad{x = f(t) * cos(t)}, \spad{y = f(t) * sin(t)}.

    plotPolar : (F -> F) -> %
      ++ plotPolar(f) plots the polar curve \spad{r = f(theta)} as theta
      ++ ranges over the interval \spad{[0, 2*%pi]}; this is the same as
      ++ the parametric curve \spad{x = f(t) * cos(t)}, \spad{y = f(t) * sin(t)}.

    plot : (%, R) -> %              -- change the range
        ++ plot(x, r) \undocumented
    parametric? : % -> B
      ++ parametric? determines whether it is a parametric plot?

    zoom : (%, R) -> %
        ++ zoom(x, r) \undocumented
    zoom : (%, R, R) -> %
        ++ zoom(x, r, s) \undocumented
    refine : (%, R) -> %
        ++ refine(x, r) \undocumented
    refine : % -> %
      ++ refine(p) performs a refinement on the plot p

    tRange : % -> R
      ++ tRange(p) returns the range of the parameter in a parametric plot p

    minPoints : () -> I
      ++ minPoints() returns the minimum number of points in a plot
    setMinPoints : I -> I
      ++ setMinPoints(i) sets the minimum number of points in a plot to i
    maxPoints : () -> I
      ++ maxPoints() returns the maximum number of points in a plot
    setMaxPoints : I -> I
      ++ setMaxPoints(i) sets the maximum number of points in a plot to i
    screenResolution : () -> I
      ++ screenResolution() returns the screen resolution
    setScreenResolution : I -> I
      ++ setScreenResolution(i) sets the screen resolution to i
    adaptive? : () -> B
      ++ adaptive?() determines whether plotting be done adaptively
    setAdaptive : B -> B
      ++ setAdaptive(true) turns adaptive plotting on
      ++ \spad{setAdaptive(false)} turns adaptive plotting off
    numFunEvals : () -> I
      ++ numFunEvals() returns the number of points computed
    debug : B -> B
      ++ debug(true) turns debug mode on
      ++ \spad{debug(false)} turns debug mode off

  Implementation ==> add
    import from PointPackage(DoubleFloat)

--% local functions

    checkRange     : R -> R
      -- checks that left-hand endpoint is less than right-hand endpoint
    intersect      : (R, R) -> R
      -- intersection of two intervals
    union          : (R, R) -> R
      -- union of two intervals
    join           : (L C, I) -> R
    parametricRange : % -> R
    select         : (L P, P -> F, (F, F) -> F) -> F
    rangeRefine    : (C, R) -> C
    adaptivePlot   : (C, R, R, R, I) -> C
    basicPlot      : (F -> P, R) -> C
    basicRefine    : (C, R) -> C
    pt             : (F, F) -> P
    Fnan?           : F -> Boolean
    Pnan?           : P -> Boolean

--% representation

    Rep := Record( parametric : B, _
                   display : L R, _
                   bounds : L R, _
                   axisLabels : L S, _
                   functions : L C )

--% global constants

    ADAPTIVE : B := true
    MINPOINTS : I := 49
    MAXPOINTS : I := 1000
    NUMFUNEVALS : I := 0
    SCREENRES : I := 500
    ANGLEBOUND : F := cos inv (4::F)
    DEBUG : B := false

    Fnan?(x) == x ~= x
    Pnan?(x) == any?(Fnan?, x)

--% graphics output

    listBranches plot ==
      outList : L L P := []
      for curve in plot.functions repeat
        -- curve is C
        newl : L P := []
        for p in curve.points repeat
          if not Pnan? p then newl := cons(p, newl)
          else if not empty? newl then
                outList := concat(newl := reverse! newl, outList)
                newl := []
        if not empty? newl then outList := concat(newl := reverse! newl, outList)
--      print(outList::OutputForm)
      outList

    checkRange r == (low(r) > high(r) => error "ranges cannot be negative"; r)
    intersect(s, t) == checkRange(max(low(s), low(t))..min(high(s), high(t)))
    union(s, t) == min(low(s), low(t))..max(high(s), high(t))
    join(l, i) ==
      rr := first l
      u : R :=
        i = 0 => first(rr.ranges)
        i = 1 => second(rr.ranges)
        third(rr.ranges)
      for r in rest l repeat
        i = 0 => u := union(u, first(r.ranges))
        i = 1 => u := union(u, second(r.ranges))
        u := union(u, third(r.ranges))
      u
    parametricRange r == first(r.bounds)

    minPoints() == MINPOINTS
    setMinPoints n ==
      if n < 3 then error "three points minimum required"
      if MAXPOINTS < n then MAXPOINTS := n
      MINPOINTS := n
    maxPoints() == MAXPOINTS
    setMaxPoints n ==
      if n < 3 then error "three points minimum required"
      if MINPOINTS > n then MINPOINTS := n
      MAXPOINTS := n
    screenResolution() == SCREENRES
    setScreenResolution n ==
      if n < 2 then error "buy a new terminal"
      SCREENRES := n
    adaptive?() == ADAPTIVE
    setAdaptive b == ADAPTIVE := b
    parametric? p == p.parametric

    numFunEvals() == NUMFUNEVALS
    debug b == DEBUG := b

    xRange plot == second plot.bounds
    yRange plot == third plot.bounds
    tRange plot == first plot.bounds

    select(l, f, g) ==
      m := f first l
      if Fnan? m then m := 0
      for p in rest l repeat
        n := m
        m := g(m, f p)
        if Fnan? m then m := n
      m

    rangeRefine(curve, nRange) ==
      checkRange nRange; l := low(nRange); h := high(nRange)
      t := curve.knots; p := curve.points; f := curve.source
      while not(empty?(t)) and first t < l repeat
        (t := rest t; p := rest p)
      c : L F := []; q : L P := []
      while not(empty?(t)) and (first t) <= h repeat
        c := concat(first t, c); q := concat(first p, q)
        t := rest t; p := rest p
      if empty?(c) then return basicPlot(f, nRange)
      if first c < h then
        c := concat(h, c)
        q := concat(f h, q)
        NUMFUNEVALS := NUMFUNEVALS + 1
      t := c := reverse! c; p := q := reverse! q
      s := (h-l)/(minPoints()::F-1)
      if (first t) ~= l then
        t := c := concat(l, c)
        p := q := concat(f l, p)
        NUMFUNEVALS := NUMFUNEVALS + 1
      while not(empty?(rest(t))) repeat
        n := wholePart((second(t) - first(t))/s)
        d := (second(t) - first(t))/((n+1)::F)
        for i in 1..n repeat
          t.rest := concat(first(t) + d, rest t)
          p.rest := concat(f second t, rest p)
          NUMFUNEVALS := NUMFUNEVALS + 1
          t := rest t; p := rest p
        t := rest t
        p := rest p
      xRange := select(q, xCoord, min) .. select(q, xCoord, max)
      yRange := select(q, yCoord, min) .. select(q, yCoord, max)
      [ f, [nRange, xRange, yRange], c, q]

    adaptivePlot(curve, tRange, xRange, yRange, pixelfraction) ==
      xDiff := high(xRange) - low(xRange)
      yDiff := high(yRange) - low(yRange)
      xDiff = 0 or yDiff = 0 => curve
      l := low(tRange); h := high(tRange)
      (tDiff := h-l) = 0 => curve
--      if (EQL(yDiff, _$NaNvalue$Lisp)$Lisp) then yDiff := 1::F
      t := curve.knots
      #t < 3 => curve
      p := curve.points; f := curve.source
      minLength : F := 4::F/500::F
      maxLength : F := 1::F/6::F
      tLimit := tDiff/(pixelfraction*500)::F
      while not(empty?(t)) and first t < l repeat (t := rest t; p := rest p)
      #t < 3 => curve
      headert := t; headerp := p

      -- jitter the input points
--      while not(empty?(rest rest t)) repeat
--        t0 := second(t); t1 := third(t)
--        jitter := (random()$I) :: F
--        jitter := sin (jitter)
--        val := t0 + jitter * (t1-t0)/10::F
--        t.2 := val; p.2 := f val
--        t := rest t; p := rest p
--      t := headert; p := headerp

      st := headert; sp := headerp
      n : I := 0
      while not(empty?(rest(rest(st)))) repeat
        t0 := first(st); t1 := second(st); t2 := third(st)
        if t2 > h then break
        t2 - t0 < tLimit =>
            st := rest st
            sp := rest sp
        x0 := xCoord first(sp); y0 := yCoord first(sp)
        x1 := xCoord second(sp); y1 := yCoord second(sp)
        x2 := xCoord third(sp); y2 := yCoord third(sp)
        a1 := (x1-x0)/xDiff; b1 := (y1-y0)/yDiff
        a2 := (x2-x1)/xDiff; b2 := (y2-y1)/yDiff
        s1 := sqrt(a1^2+b1^2); s2 := sqrt(a2^2+b2^2)
        dp := a1*a2+b1*b2

        s1 < maxLength and s2 < maxLength and _
          (s1 = 0::F or s2 = 0::F or
             s1 < minLength and s2 < minLength or _
             dp/s1/s2 > ANGLEBOUND) =>
                st := rest st
                sp := rest sp
        if n > MAXPOINTS then break else n := n + 1
        t := st
        p := sp
        tj := (t0+t1)/2::F
        qsetrest!(t, cons(tj, rest t))
        qsetrest!(p, cons(f tj, rest p))
        t := rest t; p := rest p
        t := rest t; p := rest p

        tj := (t1+t2)/2::F
        qsetrest!(t, cons(tj, rest t))
        qsetrest!(p, cons(f tj, rest p))
      n > 0 =>
        NUMFUNEVALS := NUMFUNEVALS + n
        t := curve.knots; p := curve.points
        xRange := select(p, xCoord, min) .. select(p, xCoord, max)
        yRange := select(p, yCoord, min) .. select(p, yCoord, max)
        [ curve.source, [tRange, xRange, yRange], t, p ]
      curve

    basicPlot(f, tRange) ==
      checkRange tRange
      l := low(tRange)
      h := high(tRange)
      t : L F := list l
      p : L P := list f l
      s := (h-l)/(minPoints()-1)::F
      for i in 2..minPoints()-1 repeat
        l := l+s
        t := concat(l, t)
        p := concat(f l, p)
      t := reverse! concat(h, t)
      p := reverse! concat(f h, p)
--      print(p::OutputForm)
      xRange : R := select(p, xCoord, min) .. select(p, xCoord, max)
      yRange : R := select(p, yCoord, min) .. select(p, yCoord, max)
      [ f, [tRange, xRange, yRange], t, p ]

    zoom(p, xRange) ==
      [p.parametric, [xRange, third(p.display)], p.bounds, _
       p.axisLabels, p.functions]
    zoom(p, xRange, yRange) ==
      [p.parametric, [xRange, yRange], p.bounds, _
       p.axisLabels, p.functions]

    basicRefine(curve, nRange) ==
      tRange : R := first curve.ranges
      -- curve := copy$C curve  -- Yet another compiler bug
      curve : C := [curve.source, curve.ranges, curve.knots, curve.points]
      t := curve.knots := copy curve.knots
      p := curve.points := copy curve.points
      l := low(nRange); h := high(nRange)
      f := curve.source
      while not(empty?(rest(t))) and first t < h repeat
        second(t) < l => (t := rest t; p := rest p)
        -- insert new point between t.0 and t.1
        tm : F := (first(t) + second(t))/2::F
--         if DEBUG then output$O (tm::E)
        pm := f tm
        NUMFUNEVALS := NUMFUNEVALS + 1
        t.rest := concat(tm, rest t); t := rest rest t
        p.rest := concat(pm, rest p); p := rest rest p
      t := curve.knots; p := curve.points
      xRange := select(p, xCoord, min) .. select(p, xCoord, max)
      yRange := select(p, yCoord, min) .. select(p, yCoord, max)
      [ curve.source, [tRange, xRange, yRange], t, p ]

    refine p == refine(p, parametricRange p)
    refine(p, nRange) ==
      NUMFUNEVALS := 0
      tRange := parametricRange p
      nRange := intersect(tRange, nRange)
      curves : L C := [basicRefine(c, nRange) for c in p.functions]
      xRange := join(curves, 1); yRange := join(curves, 2)
      if adaptive? then
        tlimit := if parametric? p then 8 else 1
        curves := [adaptivePlot(c, nRange, xRange, yRange, _
                   tlimit) for c in curves]
        xRange := join(curves, 1); yRange := join(curves, 2)
--      print(NUMFUNEVALS::OUT)
      [p.parametric, p.display, [tRange, xRange, yRange], _
       p.axisLabels, curves ]

    plot(p : %, tRange : R) ==
      -- re plot p on a new range making use of the points already
      -- computed if possible
      NUMFUNEVALS := 0
      curves : L C := [rangeRefine(c, tRange) for c in p.functions]
      xRange := join(curves, 1); yRange := join(curves, 2)
      if adaptive? then
        tlimit := if parametric? p then 8 else 1
        curves := [adaptivePlot(c, tRange, xRange, yRange, tlimit) for c in curves]
        xRange := join(curves, 1); yRange := join(curves, 2)
--      print(NUMFUNEVALS::OUT)
      [ p.parametric, [xRange, yRange], [tRange, xRange, yRange],
        p.axisLabels, curves ]

    pt(xx, yy) == point(l : L F := [xx, yy])

    myTrap : (F-> F, F) -> F
    myTrap(ff : F-> F, f : F) : F ==
      s := trapNumericErrors(ff(f))$Lisp :: Union(F, "failed")
      s case "failed" => 0
      r : F := s@F
      r > max()$F => max()$F
      r < min()$F => min()$F
      r

    plot(f : F -> F, xRange : R) ==
      p := basicPlot((u1 : F) : P +-> pt(u1, myTrap(f, u1)), xRange)
      r := p.ranges
      NUMFUNEVALS := minPoints()
      if adaptive? then
        p := adaptivePlot(p, first r, second r, third r, 1)
        r := p.ranges
      [false, rest(r), r, [], [p]]

    plot(f : F -> F, xRange : R, yRange : R) ==
      p := plot(f, xRange)
      p.display := [xRange, checkRange yRange]
      p

    plot(f : F -> F, g : F -> F, tRange : R) ==
      p := basicPlot((z1 : F) : P +-> pt(myTrap(f, z1), myTrap(g, z1)), tRange)
      r := p.ranges
      NUMFUNEVALS := minPoints()
      if adaptive? then
        p := adaptivePlot(p, first r, second r, third r, 8)
        r := p.ranges
      [true, rest(r), r, [], [p]]

    plot(f : F -> F, g : F -> F, tRange : R, xRange : R, yRange : R) ==
      p := plot(f, g, tRange)
      p.display := [checkRange xRange, checkRange yRange]
      p

    pointPlot(f : F -> P, tRange : R) ==
      p := basicPlot(f, tRange)
      r := p.ranges
      NUMFUNEVALS := minPoints()
      if adaptive? then
        p := adaptivePlot(p, first r, second r, third r, 8)
        r := p.ranges
      [true, rest(r), r, [], [p]]

    pointPlot(f : F -> P, tRange : R, xRange : R, yRange : R) ==
      p := pointPlot(f, tRange)
      p.display := [checkRange xRange, checkRange yRange]
      p

    plot(l : L(F -> F), xRange : R) ==
      if empty?(l) then error "empty list of functions"
      t : L C := [ basicPlot((z1 : F) : P +-> pt(z1, myTrap(f, z1)), xRange) for f in l ]
      yRange := join(t, 2)
      NUMFUNEVALS := # l * minPoints()
      if adaptive? then
        t := [adaptivePlot(p, xRange, xRange, yRange, 1) _
                for f in l for p in t]
        yRange := join(t, 2)
--      print(NUMFUNEVALS::OUT)
      [false, [xRange, yRange], [xRange, xRange, yRange], [], t]

    plot(l : L(F -> F), xRange : R, yRange : R) ==
      p := plot(l, xRange)
      p.display := [xRange, checkRange yRange]
      p

    plotPolar(f, thetaRange) ==
      plot((u1 : F) : F +-> f(u1) * cos(u1), (v1 : F) : F +-> f(v1) * sin(v1), thetaRange)

    plotPolar f == plotPolar(f, segment(0, 2*pi()))

--% terminal output

    coerce r ==
      spaces : OUT := message("   ")
      xSymbol := message("x = ")
      ySymbol := message("y = ")
      tSymbol := message("t = ")
      plotSymbol := message("PLOT")
      tRange := (parametricRange r) :: OUT
      f : L OUT := []
      for curve in r.functions repeat
        xRange := second(curve.ranges) :: OUT
        yRange := third(curve.ranges) :: OUT
        l : L OUT := [xSymbol, xRange, spaces, ySymbol, yRange]
        if parametric? r then
          l := concat!([tSymbol, tRange, spaces], l)
        h : OUT := hconcat l
        l := [p::OUT for p in curve.points]
        f := concat(vconcat concat(h, l), f)
      prefix(plotSymbol, reverse! f)

)abbrev package PLOT1 PlotFunctions1
++ Authors: R.T.M. Bronstein, C.J. Williamson
++ Date Created: Jan 1989
++ Basic Operations: plot, plotPolar
++ Related Constructors:
++ Also See:
++ AMS Classifications:
++ Keywords:
++ References:
++ Description: PlotFunctions1 provides facilities for plotting curves
++ where functions SF -> SF are specified by giving an expression
PlotFunctions1(S : ConvertibleTo InputForm) : with
    plot : (S, Symbol, Segment DoubleFloat) -> Plot
      ++ plot(fcn, x, seg) plots the graph of \spad{y = f(x)} on a interval
    plot : (S, S, Symbol, Segment DoubleFloat) -> Plot
      ++ plot(f, g, t, seg) plots the graph of \spad{x = f(t)}, \spad{y = g(t)} as t
      ++ ranges over an interval.
    plotPolar : (S, Symbol, Segment DoubleFloat) -> Plot
      ++ plotPolar(f, theta, seg) plots the graph of \spad{r = f(theta)} as
      ++ theta ranges over an interval
    plotPolar : (S, Symbol) -> Plot
      ++ plotPolar(f, theta) plots the graph of \spad{r = f(theta)} as
      ++ theta ranges from 0 to 2 pi
  == add
    import from MakeFloatCompiledFunction(S)

    plot(f, x, xRange) == plot(makeFloatFunction(f, x), xRange)
    plotPolar(f, theta) == plotPolar(makeFloatFunction(f, theta))
    plot(f1, f2, t, tRange) ==
      plot(makeFloatFunction(f1, t), makeFloatFunction(f2, t), tRange)
    plotPolar(f, theta, thetaRange) ==
      plotPolar(makeFloatFunction(f, theta), thetaRange)

--Copyright (c) 1991-2002, The Numerical ALgorithms Group Ltd.
--All rights reserved.
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--
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--
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--      notice, this list of conditions and the following disclaimer in
--      the documentation and/or other materials provided with the
--      distribution.
--
--    - Neither the name of The Numerical ALgorithms Group Ltd. nor the
--      names of its contributors may be used to endorse or promote products
--      derived from this software without specific prior written permission.
--
--THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS
--IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
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--PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER
--OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
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