For labels that want it add nice arrow paths that point just over the
respective axis. Couple label text offset from the axis line based on
parent 'tickTextOffset' setting. Drop `YSticky` it was not enough
meat to bother with.
The min tick size is the smallest step an instrument can move in value
(think the number of decimals places of precision the value can have).
We start leveraging this in a few places:
- make our internal "symbol" type expose it as part of it's api
so that it can be passed around by UI components
- in y-axis view box scaling, use it to keep the bid/ask spread (L1 UI)
always on screen even in the case where the spread has moved further
out of view then the last clearing price
- allows the EMS to determine dark order live order submission offsets
Our first major UI "mode" (yes kinda like the modes in emacs) that has
handles to a client side order book api, line and arrow editors, and
interacts with a spawned `emsd` (the EMS daemon actor).
Buncha cleaning and fixes in here for various thingers as well.
Since the "crosshair" is growing more and more UX implementation details
it probably makes sense to call it what it is; a python level mouse
abstraction. Add 2 internal sets: `_hovered` for allowing mouse hovered
objects to register themselves to other cursor aware components, and
`_trackers` for allowing scene items to "track" cursor movements via
a `on_tracked_source()` callback.
Support tracking the mouse cursor using a new `on_tracked_sources()`
callback method. Make hovered highlight a bit thicker and highlight when
click-dragged. Add a delete method for removing from the scene along
with label.
Leverages `QGraphicsItem.cacheMode` to speed up interactivity via
less `.paint()` calls (on mouse interaction) and redraws of the
underlying path when there are no transformations (other then a shift).
In order to keep the "flat bar on new time period" UX, a couple special
methods have to be triggered to get a redraw of the pixel buffer when
appending new data.
Use `QPainterPath.controlPointRect()` over `.boundingRect()` since
supposedly it's a lot faster. Drop all use of `QPicture` (since it seems
to conflict with the pixel buffer stuff?) and it doesn't give any
measurable speedup when drawing the "last bar" lines.
Oh, and add some profiling for now.
This is a bit hacky (what with array indexing semantics being relative
to the primary index's "start" value but it works. We'll likely want
to somehow wrap this index finagling into an API soon.
Failed at using either.
Quirks in numba's typing require specifying readonly arrays by
composing types manually.
The graphics item path thing, while it does take less time to write on
bar appends, seems to be slower in general in calculating the
``.boundingRect()`` value. Likely we'll just add manual max/min tracking
on array updates like ``pg.PlotCurveItem`` to squeeze some final juices
on this.
Pertains further to #109.
Instead of redrawing the entire `QPainterPath` every time there's
a historical bars update just use `.addPath()` to slap in latest
history. It seems to work and is fast. This also seems like it will be
a great strategy for filling in earlier data, woot!
This gives a massive speedup when viewing large bar sets (think a day's
worth of 5s bars) by using the `pg.functions.arrayToQPath()` "magic"
binary array writing that is also used in `PlotCurveItem`. We're using
this same (lower level) function directly to draw bars as part of one
large path and it seems to be painting 15k (ish) bars with around 3ms
`.paint()` latency. The only thing still a bit slow is the path array
generation despite doing it with `numba`. Likely, either having multiple
paths or, only regenerating the missing backing array elements should
speed this up further to avoid slight delays when incrementing the bar
step.
This is of course a first draft and more cleanups are coming.
This makes it so you don't have to ctrl-c kill apps.
Add in the experimental openGL support even though I'm pretty sure it's
not being used much for curve plotting (but could be wrong).
Break the chart update code for fsps into a new task (add a nursery) in
new `spawn_fsps` (was `chart_from_fsps`) that async requests actor
spawning and initial historical data (all CPU bound work). For multiple
fsp subcharts this allows processing initial output in parallel
(multi-core). We might want to wrap this in a "feed" like api
eventually. Basically the fsp startup sequence is now:
- start all requested fsp actors in an async loop and wait for
historical data to arrive
- loop through them all again to start update tasks which do chart
graphics rendering
Add separate x-axis objects for each new subchart (required by
pyqtgraph); still need to fix hiding unnecessary ones.
Add a `ChartPlotWidget._arrays: dict` for holding overlay data distinct
from ohlc. Drop the sizing yrange to label heights for now since it's
pretty much all gone to hell since adding L1 labels. Fix y-stickies to
look up correct overly arrays.
Requires decent modification of the built-in ``ViewBox``.
We do away with the zoom functionality for now and instead just add
a label full of some simple stats on the bounded data.
I think this gets us to the same output as TWS both on booktrader and
the quote details pane. In theory there might be logic needed to
decreases an L1 queue size on trades but can't seem to get it without
getting -ves displayed occasionally - thus leaving it for now.
Also, fix the max-min streaming logic to actually do its job, lel.
Start a simple API for L1 bid/ask labels.
Make `LevelLabel` draw a line above/below it's text (instead of the
rect fill we had before) since it looks much simpler/slicker.
Generalize the label text orientation through bounding rect
geometry positioning.
Until we get a better datum "cursor" figured out just draw the flat bar
despite the extra overhead. The reason to do this in 2 separate calls is
detailed in the comment but basic gist is that there's a race between
writer and reader of the last shm index.
Oh, and toss in some draft symbol search label code.
Not sure what fixed it exactly, and I guess we didn't need any relative
DPI scaling factor after all. Using the 3px margin on the level label
seems to make it look nice for any font size (i think) as well.
Gonna need some cleanup after this one.
Make our own ``Axis`` and have it call an impl specific ``.resize()``
such that different axes can size to their own spec. Allow passing in a
"typical maximum value string" which will be used by default for sizing
the axis' minor dimension; a common value should be passed to all axes
in a linked split charts widget. Add size hinting for axes labels such
that they can check their parent (axis) for desired dimensions if
needed.
Compute the size in pixels the label based on the label's contents.
Eventually we want to have an update system that can iterate through
axes and labels to do this whenever needed (eg. after widget is moved
to a new screen with a different DPI).
Avoid drawing a new new sticky position if the mouse hasn't moved to the
next (rounded) index in terms of the scene's coordinates. This completes
the "discrete-ization" of the mouse/cursor UX.
Finalizing this feature helped discover and solve
pyqtgraph/pyqtgraph#1418 which masssively improves interaction
performance throughout the whole lib!
Hide stickys on startup until cursor shows up on plot.
This is likely a marginal improvement but is slightly less execution and
adds a coolio black border around the label. Drop all the legacy code
from quantdom which was quite a convoluted mess for "coloring".
Had to tweak sticky offsets to get the crosshair to line up right; not
sure what that's all about yet.
With the improved update logic on `BarsItems` it doesn't seem to be
necessary. Remove y sticky for overlays for now to avoid clutter that
looks like double draws when the last overlay value is close to the last
price.
It seems a plethora of problems (including drawing performance) are due
to trying to hack around the strange rendering bug in Qt with `QLineF`
with y1 == y2. There was all sorts of weirdness that would show up with
trying (a hack) to just set all 4 points to the same value including
strange infinite diagonal ghost lines randomly on charts. Instead, just
place hold these flat bar's 'body' line with a `None` and filter the
null values out before calling `QPainter.drawLines()`. This results
in simply no body lines drawn for these datums. We can probably `numba`
the filtering too if it turns out to be a bottleneck.
Add a new graphic `LineDot` which is a `pg.CurvePoint` that draws
a simple filled dot over a curve at the specified index.
Add support for adding these cursor-dots to the crosshair/mouse through
a new `CrossHair.add_curve_cursor()`. Discretized the vertical line
updates on the crosshair such that it's only drawn in the middle of
the current bar in the main chart.
Makes the chart act like tws where each new time step increment the
chart shifts to the right so that the last bar stays in place. This
gets things looking like a proper auto-trading UX.
Added a couple methods to ``ChartPlotWidget`` to make this work:
- ``.default_view()`` to set the preferred view based on user settings
- ``.increment_view()`` to shift the view one time frame right
Also, split up the `.update_from_array()` method to be curve/ohlc
specific allowing for passing in a struct array with a named field
containing curve data more straightforwardly. This also simplifies the
contest label update functions.
Lookup overlay contents from the OHLC struct array (for now / to make
things work) and fix anchoring logic with better offsets to keep
contents labels super tight to the edge of the view box. Unfortunately,
had to hack the label-height-calc thing for avoiding overlap of graphics
with the label; haven't found a better solution yet and pyqtgraph seems
to require more rabbit holing to figure out something better. Slap in
some inf lines for over[sold/bought] rsi conditions thresholding.
If we know the max and min in view then on datum updates we can avoid
resizing the y-range when a new max/min has not yet arrived.
This adds a very naive numpy calc in the drawing thread which we can
likely improve with a more efficient streaming alternative which can
also likely be run in a fsp subactor. Also, since this same calc is
essentially done inside `._set_yrange()` we will likely want to allow
passing the result into the method to avoid duplicate work.
Just like for the source OHLC, we now have the chart parent actor create
an fsp shm array and use it to read back signal data for plotting.
Some tweaks to get the price chart (and sub-charts) to load historical
datums immediately instead of waiting on an initial quote.
Added a comment to clarify, ish.
Add `ChartPlotWidget._overlays` as registry of curves added on top of
main graphics. Hackishly (ad-hoc-ishly?) update the curve assuming the
data resides in the same `._array` for now (which it does for historical
vwap).
Allow passing a fixed ylow, yhigh tuple to `._set_yrange()` which avoids
recomputing the range from data if desired (eg. rsi-like bounded
signals). Add support for overlay curves to the OHLC chart and add basic
support to brokers which provide a historical 'vwap`. The data array
increment logic had to be tweaked to copy the vwap from the last bar.
Oh, and hack the subchart curves with two extra prepended datums to make
them align "better" with the ohlc main chart; need to talk to
`pyqtgraph` core about how to do this more correctly.
By mapping any in view "contents labels" to the range of the
``ViewBox``'s data we can avoid having graphics overlap with labels.
Take this approach instead of specifying a min y-range using the std
and activate the range compute on resize and mouser scrolling.
Also, add y-sticky update for signal plots.
Use two separate `QPicture` instances:
- one for the 3 lines for the last bar
- one for all the historical bars lines
On price changes update the last bar and only update historical bars
when the current bar's period expires (when a new bar is "added").
Add a flag `just_history` for this `BarItems.draw_lines()`.
Also, switch the internal lines array/buffer to a 2D numpy array to avoid
the type-cast step and instead just flatten using `numpy.ravel()`.
Overall this should avoid the problem of draws getting slower over time
as new bars are added to the history since price updates only redraw
a single bar to the "last" `QPicture` instance. Ideally in the future we
can make the `history` `QPicture` a `QPixmap` but it looks like this
will require some internal work in `pyqtgraph` to support it.
Use a ``rec2array`` struct array converter to generate lines sequence
faster. Start looking into using a `QPixmap` to avoid redrawing all
bars every update.
Add a default "contents label" (eg. OHLC values for bar charts) to each
chart and update on crosshair interaction.
Few technical changes to make this happen:
- adjust bar graphics to have the HL line be in the "middle" of the
underlying arrays' "index range" in the containing view.
- add a label dict each chart's graphics name to a label + update routine
- use symbol names instead of this "main" identifier crap for referring to
particular price curves/graphics
This is a first attempt at a financial signal processing subsystem which
utilizes async generators for streaming frames of numpy array data
between actors. In this initial attempt the focus is on processing price
data and relaying it to the chart app for real-time display. So far this
seems to work (with decent latency) but much more work is likely needed
around improving the data model for even better latency and less data
duplication.
Surprisingly (or not?) a lot of simplifications to the charting code
came out of this in terms of conducting graphics updates in streaming
tasks instead of hiding them inside the obfuscated mess that is the
Qt-style-inheritance-OO-90s-trash. The goal from here on wards will be
to enforce strict semantics around reading and writing of data such that
state is kept outside "object trees" as much as possible and streaming
function semantics guide our flow model. Unsurprisingly, this reduction
in "instance state" is happening wherever we use `trio` ;)
A little summary on the technical changes:
- not going to explain the fsp system yet; it's too nascent and
probably going to get some heavy editing.
- drop any "update" methods from the `LinkedCharts` type since each
sub-chart will have it's own update task and thus a separate update
loop; further individual graphics (per chart) may eventually require
this same design.
- delete `ChartView`; moved into separate mod.
- add "stream from fsp" task to start our foray into real-time actor
processed numpy streaming.
Wait for a first actual real-time quote before starting graphics update
tasks. Use the new normalized tick format brokers are expected to emit
as a `quotes['ticks']` list. Auto detect time frame from historical
bars.
Add `ChartPlotWidget.add_plot()` to add sub charts for indicators which
can be updated independently. Clean up rt bar update code and drop some
legacy ohlc loading cruft.
Stop with all this "main chart" special treatment.
Manage all lines in the same way across all referenced plots.
Add `CrossHair.add_plot()` for adding new plots dynamically.
Just, smh.
There's really nothing coupling it to the graphics class (which frankly
also seems like it doesn't need to be a class.. Qt).
Add support to `.update_from_array()` for diffing with the input array
and creating additional bar-lines where necessary. Note, there are still
issues with the "correctness" here in terms of bucketing open/close
values in the time frame / bar range. Also, this jamming of each bar's 3
lines into a homogeneous array seems like it could be better done with
struct arrays and avoid all this "index + 3" stuff.
Flat bars have a rendering issue we work around by hacking values in `QLineF`
but we have to revert those on any last bar that is being updated in
real-time. Comment out candle implementations for now; we can get back
to it if/when the tinas unite. Oh, and make bars have a little space
between them.
Don't allow zooming to less then a min number of data points. Allow
panning "outside" the data set (i.e. moving one of the sequence "ends"
to the middle of the view. Start adding logging.
For whatever reason if the `QLineF` high/low values are the same a weird
little rectangle is drawn (my guess is a `float` precision error of some
sort). Instead, if they're the same just use one of the values.
Also, store local vars to avoid so many lookups.
`pg.PlotCurveItem.setData()` is normally used for real-time updates to
curves and takes in a whole new array of data to graphics.
It makes sense to stick with this interface especially if
the current datum graphic will originally be drawn from tick quotes and
later filled in when bars data is available (eg. IB has this option in
TWS charts for volume). Additionally, having a data feed api where the push
process/task can write to shared memory and the UI task(s) can read from
that space is ideal. It allows for indicator and algo calculations to be
run in parallel (via actors) with initial price draw instructions
such that plotting of downstream metrics can be "pipelined" into the
chart UI's render loop. This essentially makes the chart UI async
programmable from multiple remote processes (or at least that's the
goal).
Some details:
- Only store a single ref to the source array data on the
`LinkedSplitCharts`. There should only be one reference since the main
relation is **that** x-time aligned sequence.
- Add `LinkedSplitCharts.update_from_quote()` which takes in a quote
dict and updates the OHLC array from it's contents.
- Add `ChartPlotWidget.update_from_array()` method to trigger graphics
updates per chart with consideration for overlay curves.
This makes a OHLC graphics "sequence" update very similar (actually API
compatible) with `pg.PlotCurveItem.setData()`. The difference here is
that only latest OHLC datum is used to update the charts last bar.
This was a mess before with a weird loop using the parent split charts
to update all "indicators". Instead just have each plot do its own
yrange updates since the signals are being handled just fine per plot.
Handle both the OHLC and plane line chart cases with a hacky `try:,
except IndexError:` for now.
Oh, and move the main entry point for the chart app to the relevant
module. I added some WIP bar update code for the moment.
Speed up the lines array creation using proper slice assignment.
This gives another 10% speedup to the historical price rendering.
Drop ``_tina_mode`` support for now since we're not testing it.
Previously graphics were loaded and rendered implicitly during the
import and creation of certain objects. Remove all this and instead
expect client code to pass in the OHLC sequence to plot. Speed up
the bars graphics rendering by simplifying to a single iteration of
the input array; gives about a 2x speedup.
Move chart resize code into our ``ViewBox`` subtype (a ``ChartView``)
in an effort to start organizing interaction behaviour closer to the
appropriate underlying objects. Add some docs for all this and do some
renaming.
Modify the default ``ViewBox`` scroll to zoom behaviour such that
whatever right-most point is visible is used as the "center" for
zooming. Add a "traditional" cross-hair cursor.
- Move out equity plotting to new module.
- Make axis margins and fonts look good on i3.
- Adjust axis labels colors to gray.
- Start commenting a lot of the code after figuring out what it all does
when cross referencing with ``pyqtgraph``.
- Add option to move date axis to middle.
Hand select necessary components to get real-time charting with
`pyqtgraph` from the `Quantdom` projects:
https://github.com/constverum/Quantdom
We've offered to collaborate with the author but have received no
response and the project has not been updated in over a year.
Given this, we are moving forward with taking the required components to
make further improvements upon especially since the `pyqtgraph` project
is now being actively maintained again.
If the author comes back we will be more then happy to contribute
modified components upstream:
https://github.com/constverum/Quantdom/issues/18
Relates to #80
This required some copy-paste of code from @matham's branch:
https://github.com/kivy/kivy/pull/5241
namely, the stuff in the `utils_async.py` module. I've added all that as
a standalone file for now.
Update the pipfile to use `kivy`'s master branch (since there seems to
be some lingering cython issues in the current release wheels).
- stop displaying search bar widget on <ctrl-c>
- if there's existing search bar content highlight it automatically
to allow user to start typing new content right away
- when activated allow search bar to insert its own set of keybinding
controls; restore prior bindings on exit
Look up the broker module and set up the loglevel locally.
Ask the arbiter for a portal to the data daemon since we can't
pass one to a subactor by reference.
Tyler Goodlet
Tyler Goodlet