Plot arrays/multiarrays as graphs?

[lucasw]

For example if a message is received with [0, 1, 2] in it, the current plot would have only those values plotted in a line left to right (assume a nominal point spacing for 1d data), and if a new message arrives with [3, 4, 5] the old graph would be completely replaced, there would be no message time history at all.

At the time of these questions it looks like the answer was no, but maybe this is possible now?

https://answers.ros.org/question/321890/visualize-or-plot-float32multiarray-data-field/
https://answers.ros.org/question/175151/rqt_plot-plot-2d-data/

[facontidavide]

With the new "Reactive Lua" function, you can do pretty much everything you want with your data.
To give more concrete suggestions, I probably need a more concrete example (I am not understanding exactly your data layout)

https://slides.com/davidefaconti/plotjuggler-reactive-scripts/fullscreen

[lucasw]

The lua scripting does look capable of it.

In this example I'm using Float32MultiArray as a 1D array, and plotting just the most recent array like this:

layout: 
  dim: []
  data_offset: 0
data: [1.9999999949504854e-06, 6.000000212225132e-06, 1.2000000424450263e-05, 1.9999999494757503e-05, 2.9999999242136255e-05, 4.199999966658652e-05, 5.6000000768108293e-05, 7.200000254670158e-05, 9.000000136438757e-05, 0.00011000000085914508, 0.0001340000017080456, 0.00016199999663513154, 0.0001939999929163605, 0.0002300000051036477, 0.0002699999895412475, 0.00031400000443682075, 0.00036199999158270657, 0.0004140000091865659, 0.00046999999904073775, 0.0005300000193528831, 0.0005939999828115106, 0.0006619999767281115, 0.0007340000011026859, 0.0008099999977275729, 0.0008900000248104334, 0.0009740000241436064, 0.001062000053934753, 0.001154000055976212, 0.0012499999720603228, 0.0013500000350177288, 0.0014400000218302011, 0.0015200000489130616, 0.0015899999998509884, 0.0016499999910593033, 0.0017000000225380063, 0.0017399999778717756, 0.001769999973475933, 0.0017900000093504786, 0.0017999999690800905, 0.0017999999690800905, 0.001791000016964972, 0.0017729999963194132, 0.0017460000235587358, 0.0017099999822676182, 0.001664999988861382, 0.0016110000433400273, 0.0015480000292882323, 0.001475999946705997, 0.001395000028423965, 0.0013050000416114926, 0.0012080000014975667, 0.001104000024497509, 0.0009929999941959977, 0.0008750000270083547, 0.000750000006519258, 0.0006179999909363687, 0.00047900000936351717, 0.0003330000035930425, 0.00018000000272877514, 1.9999999494757503e-05, -0.00014699999883305281, -0.0003209999995306134, -0.0005019999807700515, -0.0006900000153109431, -0.0008849999867379665, -0.0010870000114664435, -0.0012959999730810523, -0.0015119999879971147, -0.0017350000562146306, -0.0019650000613182783, -0.0022100000642240047, -0.002469999948516488, -0.002744999947026372, -0.0030350000597536564, -0.0033400000538676977, -0.003659999929368496, -0.003994999919086695, -0.00434499979019165, -0.00471000000834465, -0.005090000107884407]

It looks like there would need to be a for loop around getting the value of each element of the array

... for i in length of data
  series_x = TiimeseriesView.find("mobile_base/yaw_0/data.%d", index)
  -- append series_x.at(0) to list 
...

Or I could get it all in one call?

series_x = TiimeseriesView.find("mobile_base/yaw_0/data")

[facontidavide]

The correct formula would look more like:

new_series = MutableScatterXY.new("trajectory_XY")
  
function( tracker_time )
  index = 0
  while(true) do

    str = string.format("mobile_base/yaw_0/data.%d") -- X
    series_yaw = TimeseriesView.find( str )
    if series_yaw == nil then break end	 
    
    yaw = series_yaw:atTime(tracker_time)
    new_series:push_back(index, yaw)

    index = index + 1
  end 
end

As explained in the tuorial ;)

[lucasw]

Ok I put the new_series = ... line in the 'Global code' box, and cut and paste the body of function( tracker_time ) ino the same titled box below it (it appears not to care about the extra indent, so I didn't remove it). I'm allowed to save it, so no syntax errors.

I'm getting a lot of crashes, this one I think because the timeseries wasn't getting cleared and it built up too many points, it happened after a few minutes:

...
#1    Object "/opt/ros/noetic/lib/plotjuggler/plotjuggler", at 0x55c86abbb7e1, in std::_Rb_tree<QString, std::pair<QString const, QColor>, std::_Select1st<std::pair<QString const, QColor> >, std::less<QString>, std::allocator<std::pair<QString const, QColor> > >::_M_erase(std::_Rb_tree_node<std::pair<QString const, QColor> >*)
#0    Object "/opt/ros/noetic/lib/plotjuggler/plotjuggler", at 0x55c86ac65b54, in luaopen_package
Segmentation fault (Address not mapped to object [0x30])
Segmentation fault (core dumped)

But it also crashes when I put a new_series.clear() at the top of the function box- new_series doesn't necessarily exist the first time the function is called? Or an empty series can't be cleared?

[DEBUG] Create scatterplot, bool timeseries=0
Stack trace (most recent call last):
#28   Object "", at 0xffffffffffffffff, in 
#27   Object "/opt/ros/noetic/lib/plotjuggler/plotjuggler", at 0x55a2bd9e19ed, in 
#26   Object "/lib/x86_64-linux-gnu/libc.so.6", at 0x7f3f55ee40b2, in __libc_start_main
#25   Object "/opt/ros/noetic/lib/plotjuggler/plotjuggler", at 0x55a2bd9e07de, in 
#24   Object "/lib/x86_64-linux-gnu/libQt5Core.so.5", at 0x7f3f5668a115, in QCoreApplication::exec()
#23   Object "/lib/x86_64-linux-gnu/libQt5Core.so.5", at 0x7f3f566823aa, in QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>)
#22   Object "/lib/x86_64-linux-gnu/libQt5Core.so.5", at 0x7f3f566db434, in QEventDispatcherGlib::processEvents(QFlags<QEventLoop::ProcessEventsFlag>)
#21   Object "/lib/x86_64-linux-gnu/libglib-2.0.so.0", at 0x7f3f556524a2, in g_main_context_iteration
#20   Object "/lib/x86_64-linux-gnu/libglib-2.0.so.0", at 0x7f3f556523ff, in g_main_context_dispatch
#19   Object "/lib/x86_64-linux-gnu/libglib-2.0.so.0", at 0x7f3f5565217c, in g_main_context_dispatch
#18   Object "/lib/x86_64-linux-gnu/libQt5Core.so.5", at 0x7f3f566db06b, in QEventDispatcherGlib::flush()
#17   Object "/lib/x86_64-linux-gnu/libQt5Core.so.5", at 0x7f3f566da77f, in QTimerInfoList::activateTimers()
#16   Object "/lib/x86_64-linux-gnu/libQt5Core.so.5", at 0x7f3f56683809, in QCoreApplication::notifyInternal2(QObject*, QEvent*)
#15   Object "/lib/x86_64-linux-gnu/libQt5Widgets.so.5", at 0x7f3f570a50ef, in QApplication::notify(QObject*, QEvent*)
#14   Object "/lib/x86_64-linux-gnu/libQt5Widgets.so.5", at 0x7f3f5709ba65, in QApplicationPrivate::notify_helper(QObject*, QEvent*)
#13   Object "/lib/x86_64-linux-gnu/libQt5Core.so.5", at 0x7f3f566afbc4, in QObject::event(QEvent*)
#12   Object "/lib/x86_64-linux-gnu/libQt5Core.so.5", at 0x7f3f566bc3ed, in QTimer::timeout(QTimer::QPrivateSignal)
#11   Object "/lib/x86_64-linux-gnu/libQt5Core.so.5", at 0x7f3f566af327, in QMetaObject::activate(QObject*, int, int, void**)
#10   Object "/opt/ros/noetic/lib/plotjuggler/plotjuggler", at 0x55a2bda0f2f7, in QString::QString(char const*)
#9    Object "/opt/ros/noetic/lib/plotjuggler/plotjuggler", at 0x55a2bda0eb65, in QString::QString(char const*)
#8    Object "/opt/ros/noetic/lib/libplotjuggler_base.so", at 0x7f3f5787af30, in PJ::ReactiveLuaFunction::calculate()
#7    Object "/opt/ros/noetic/lib/plotjuggler/plotjuggler", at 0x55a2bdad32fd, in lua_pcallk
#6    Object "/opt/ros/noetic/lib/plotjuggler/plotjuggler", at 0x55a2bdad67b1, in lua_newuserdatauv
#5    Object "/opt/ros/noetic/lib/plotjuggler/plotjuggler", at 0x55a2bdad5624, in lua_newuserdatauv
#4    Object "/opt/ros/noetic/lib/plotjuggler/plotjuggler", at 0x55a2bdad63bf, in lua_newuserdatauv
#3    Object "/opt/ros/noetic/lib/plotjuggler/plotjuggler", at 0x55a2bdae43bb, in lua_close
#2    Object "/opt/ros/noetic/lib/plotjuggler/plotjuggler", at 0x55a2bdad6249, in lua_newuserdatauv
#1    Object "/opt/ros/noetic/lib/libplotjuggler_base.so", at 0x7f3f57886550, in sol::detail::lua_cfunction_trampoline(lua_State*, int (*)(lua_State*))
#0    Object "/opt/ros/noetic/lib/libplotjuggler_base.so", at 0x7f3f578a9248, in int sol::u_detail::binding<char const*, void (PJ::CreatedSeriesBase::*)(), PJ::CreatedSeriesXY>::call_<false, false>(lua_State*)
Segmentation fault (Address not mapped to object [(nil)])
Segmentation fault (core dumped)

When my array is larger than 100 (or whatever the max array size is set to) it doesn't update, even with clamp set.

What I have currently:

Global:

new_series = MutableScatterXY.new("trajectory_XY")

function:

  -- doesn't help
  -- if new_series == nil then
  --  return
  -- end
  -- this crashes
  -- print(new_series)
  -- this crashes, but without it it will keep building up
  -- points without end
  -- new_series.clear()

  index = 0
  while(true) do
    str = string.format("/mobile_base/yaw_0/data.%d", index)
    series_yaw = TimeseriesView.find( str )
    -- print(str, series_yaw)
    if series_yaw == nil then break end	 
 
    yaw = series_yaw:atTime(tracker_time)
    -- print(index, yaw)
    new_series:push_back(index, yaw)

    -- new_series:push_back(index, 0.34 * index)
    -- if index == 100 then break end
    index = index + 1
  end

Instead of all the overlaid plots I'd like the old ones cleared out (reducing the Buffer doesn't effect it either)

(it's also drawing a line from the last value to the first, but not super important to fix)

PlotJuggler-3 3.4.1

[facontidavide]

1. Careful, the syntax is new_series:clear(), NOT new_series.clear()
2. it is normal thet if new_series == nil then doesn't help, it will be always true.
3. The print function print(new_series) is not supported in any way.

[facontidavide]

I need to investigate the crash, though, it must not happen

[lucasw]

Ok : vs. . was the main issue (https://stackoverflow.com/questions/4911186/difference-between-and-in-lua)

[lucasw]

Looks to be working, condensing the other threads into this:

Global

new_series = MutableScatterXY.new("trajectory_XY")

function

 new_series:clear()

  index = 0
  while(true) do
    str = string.format("/mobile_base/yaw_0/data.%d", index)
    series_yaw = TimeseriesView.find( str )
    if series_yaw == nil then break end	 
 
    yaw = series_yaw:atTime(tracker_time)
    new_series:push_back(index, yaw)

    index = index + 1
  end

The 'Maximum size of arrays' may need to be increased.

plotjuggler_arrays.mp4

[yuting-fu]

I'm using ROS2 galactic, and changing MutableScatterXY to ScatterXY does the trick. Otherwise I keep getting the nil error msg. I guess because only ScatterXY or Timeseries are supported?

The rest of your script works like a charm! Thanks for the great job!

[facontidavide]

So, it is not ideal, but I added a message box with the Lua error

In this way, at least you have a (confusing) hint about errors in your script