Kernel eval peculiarities

eval code

bind = binding
eval 'require "rubyvis"', bind
vis = eval 'test.rb', bind, __FILE__, __LINE__
svg_s = vis.to_svg # a string
File.open("tmp.svg", "w") { |f| f.puts svg_s } # output for debugging only
svg_h = RSVG::Handle.new_from_data(svg_s).tap { |s| s.close }
# now render svg_h with GTK/Shoes...

test.explicit_hash.rb

# Incorrect STDERR output, incorrect plot, no errors.

require 'rubyvis'

dat = pv.range(0, 10, 0.1).map {|x|
  o = Hash.new({:x=> x, :y=> Math.sin(x) + 2+rand()})
  STDERR.puts o.inspect
  o
}
STDERR.puts "size of dat: #{dat.size}"
STDERR.puts "first x = #{dat.first[:x]}"
STDERR.puts "first y = #{dat.first[:y]}"


#dat.each do |d|
#  STDERR.puts [d.x,d.y].join("\t")
#end

#p data
w = 400
h = 200
x = pv.Scale.linear(dat, lambda {|d| d[:x]}).range(0, w)
y = pv.Scale.linear(dat, lambda {|d| d[:y]}).range(0, h)

STDERR.puts "after scale"

#/* The root panel. */
vis = pv.Panel.new()
  .width(w)
  .height(h)
  .bottom(20)
  .left(20)
  .right(10)
  .top(5)

STDERR.puts "a"
vis.add(pv.Line).
  data(dat).
  line_width(5).
  left(lambda {|d| x.scale(d[:x])}).
  bottom(lambda {|d| y.scale(d[:y])}).
  anchor("bottom").add(pv.Line).
    stroke_style('red').
    line_width(1)

STDERR.puts "b"

vis

test.implicit_hash.rb

# No errors. Works fine, output is correct.

require 'rubyvis'

dat = pv.range(0, 10, 0.1).map {|x|
  o = {:x=> x, :y=> Math.sin(x) + 2+rand()}
  STDERR.puts o.inspect
  o
}
STDERR.puts "size of dat: #{dat.size}"
STDERR.puts "first x = #{dat.first[:x]}"
STDERR.puts "first y = #{dat.first[:y]}"


#dat.each do |d|
#  STDERR.puts [d.x,d.y].join("\t")
#end

#p data
w = 400
h = 200
x = pv.Scale.linear(dat, lambda {|d| d[:x]}).range(0, w)
y = pv.Scale.linear(dat, lambda {|d| d[:y]}).range(0, h)

STDERR.puts "after scale"

#/* The root panel. */
vis = pv.Panel.new()
  .width(w)
  .height(h)
  .bottom(20)
  .left(20)
  .right(10)
  .top(5)

STDERR.puts "a"
vis.add(pv.Line).
  data(dat).
  line_width(5).
  left(lambda {|d| x.scale(d[:x])}).
  bottom(lambda {|d| y.scale(d[:y])}).
  anchor("bottom").add(pv.Line).
    stroke_style('red').
    line_width(1)

STDERR.puts "b"

vis

test.openstruct.rb

# Incorrect STDERR output and incorrect plot, no errors.

require 'rubyvis'
require 'ostruct'

dat = pv.range(0, 10, 0.1).map {|x|
  o = OpenStruct.new(:x=> x, :y=> Math.sin(x) + 2+rand())
  STDERR.puts o.inspect
  o
}
STDERR.puts "size of dat: #{dat.size}"
STDERR.puts "first x = #{dat.first.x}"
STDERR.puts "first y = #{dat.first.y}"


#dat.each do |d|
#  STDERR.puts [d.x,d.y].join("\t")
#end

#p data
w = 400
h = 200
x = pv.Scale.linear(dat, lambda {|d| d.x}).range(0, w)
y = pv.Scale.linear(dat, lambda {|d| d.y}).range(0, h)

STDERR.puts "after scale"

#/* The root panel. */
vis = pv.Panel.new()
  .width(w)
  .height(h)
  .bottom(20)
  .left(20)
  .right(10)
  .top(5)

STDERR.puts "a"
vis.add(pv.Line).
  data(dat).
  line_width(5).
  left(lambda {|d| x.scale(d.x)}).
  bottom(lambda {|d| y.scale(d.y)}).
  anchor("bottom").add(pv.Line).
    stroke_style('red').
    line_width(1)

STDERR.puts "b"

vis

test.rb

# Original test.rb. Incorrect plot.

require "rubyvis"

data = pv.range(0, 10, 0.1).map {|x| 
  OpenStruct.new({:x=> x, :y=> Math.sin(x) + 2+rand()})
}

#p data
w = 400
h = 200
x = pv.Scale.linear(data, lambda {|d| d.x}).range(0, w)
y = pv.Scale.linear(data, lambda {|d| d.y}).range(0, h)

#/* The root panel. */
vis = pv.Panel.new().
  width(w).
  height(h).
  bottom(20).
  left(20).
  right(10).
  top(5)

vis.add(pv.Line).
  data(data).
  line_width(5).
  left(lambda {|d| x.scale(d.x)}).
  bottom(lambda {|d| y.scale(d.y)}).
  anchor("bottom").add(pv.Line).
    stroke_style('red').
    line_width(1)
     
vis

#
# Next two lines are uncommented when running without continuous evaluation.
#  My app calls these after getting the Rubyvis::Panel (vis) back from eval.
#

# vis.render()
# vis.to_svg()