Ruby/Gnuplot/ GnuplotRB 中的时间轴格式

Question

在过去的几个小时里拉着我的头发。使用 GnuplotRB。尝试绘制一些时间序列，以及我尝试使用的任何格式和 xrange 选项，X 轴始终显示 1990 到 2035（这是从哪里来的？？）

下面有类似数据的例子

require 'gnuplotrb'
include GnuplotRB

x = ["2013-05-22 02:49:49",    "2013-05-22 02:56:49", "2013-05-22 02:56:59"]
y = [ 2,5,9]

p x.first
p x.last

element = Dataset.new(
  [x, y], 
  with:'lines lw 3 lt rgb "black"', 
  timefmt: "%Y-%m-%d %H:%M:%S",
  xdata: 'time',
  format_x:  "%Y-%m-%d %H:%M:%S",
#  xrange: '[ "#{x.first}":"#{x.last}" ]'
  xrange: '[ "2013-05-22 02:49:00" : "2013-05-22 02:50:00" ]'
  )

myBRTraces = Plot.new(
  element
   )

p myBRTraces.inspect
myBRTraces.to_png("/media/sf_D_DRIVE/Test/a.svg", size: [1200, 1800], truecolor:true)

[编辑] - 进一步简化代码。

我还完成了this tweak 以实际从 gnuplot 获得一些错误日志记录。我确实帮助确定了 xrange 是一个 b***，但我仍然不知道如何使它工作：

$  ruby test.rb 
"2013-05-22 02:49:49"
"2013-05-22 02:56:59"
 "#<GnuplotRB::Plot:0x00000001ba21f0 @options=Hamster::Hash[], @datasets=Hamster::Vector[#<GnuplotRB::Dataset:0x00000001ba2100 @type=:datablock, @data=#<GnuplotRB::Datablock:0x00000001ba1f70 @stored_in_file=false, @data=\"2013-05-22 02:49:49 2\\n2013-05-22 02:56:49 5\\n2013-05-22 02:56:59 9\">, @options=Hamster::Hash[:with => \"lines lw 3 lt rgb \\\"black\\\"\", :timefmt => \"%Y-%m-%d %H:%M:%S\", :xdata => \"time\", :format_x => \"%Y-%m-%d %H:%M:%S\", :xrange => \"[ \\\"2013-05-22 02:49:00\\\" : \\\"2013-05-22 02:50:00\\\" ]\"]>], @cmd=\"plot \">"    
/var/lib/gems/2.3.0/gems/gnuplotrb-0.4.0/lib/gnuplotrb/mixins/error_handling.rb:28:in `check_errors': Error in previous command ("Warning: empty x range [2013:2013], adjusting to [1992.87:2033.13]"): "Warning: empty y range [2:2], adjusting to [1.98:2.02]; gnuplot> plot $DATA1 with lines lw 3 lt rgb "black" timefmt "%Y-%m-%d %H:%M:%S" xdata time format x "%Y-%m-%d %H:%M:%S" xrange [ "2013-05-22 02:49:00" : "2013-05-22 02:50:00" ]; line 4: unexpected or unrecognized token" (GnuplotRB::GnuplotError)
from /var/lib/gems/2.3.0/gems/gnuplotrb-0.4.0/lib/gnuplotrb/staff/terminal.rb:183:in `close'
from /var/lib/gems/2.3.0/gems/gnuplotrb-0.4.0/lib/gnuplotrb/plot.rb:85:in `plot'
from /var/lib/gems/2.3.0/gems/gnuplotrb-0.4.0/lib/gnuplotrb/mixins/plottable.rb:111:in `to_specific_term'
from /var/lib/gems/2.3.0/gems/gnuplotrb-0.4.0/lib/gnuplotrb/mixins/plottable.rb:53:in `method_missing'

我没有收到“警告：空 x 范围 [2013:2013]”

Answer 1

从documentation 看来，似乎需要将特定于情节的设置传递给Plot.new 调用：

在 gnuplot doc (pp. 105-181) 中解释了 Plot 的选项。阴谋 选项以与 Dataset 相同的方式转换为 gnuplot 格式 （除了在每个选项之前添加“设置”）。

因此：

element = Dataset.new(
  [x, y],
  with: 'lines lw 3 lt rgb "black"',
  using: '1:2'
)

myBRTraces = Plot.new(
  element,
  timefmt: "%Y-%m-%d %H:%M:%S",
  xdata: 'time',
  format_x:  "%Y-%m-%d %H:%M:%S",
  xrange: '[ "2013-05-22 02:49:00" : "2013-05-22 02:50:00" ]',
  yrange: '[0:10]'
)

否则，gnuplotrb 会尝试在单个 plot 命令中组合传递给 Dataset.new 的所有选项（如您发布的错误消息中所示），然后失败：

plot $DATA1 with lines lw 3 lt rgb "black" timefmt "%Y-%m-%d %H:%M:%S" xdata time format x "%Y-%m-%d %H:%M:%S" xrange [ "2013-05-22 02:49:00" : "2013-05-22 02:50:00" ];