Commands

Commands

This page lists the current interactive commands implemented in libraries/GRoot/GCommands.cxx and libraries/GRoot/GCanvas.cxx.

Most histogram commands are dispatched through the GRootInteract() TExec. GCanvas adds that exec automatically. A normal ROOT TCanvas can use the same command path if the exec is added manually:

canvas->AddExec("groot_interact", "GRootInteract()");

Prompt Help

The groot prompt catches these help commands before passing input to ROOT:

Prompt command	Action
?	Print a short command overview.
help	Print the same short overview.
help commands	Print a compact key and mouse command summary.
help markers	Print marker usage notes.
help fitting	Print 1D fit workflow notes.
help projections	Print projection workflow notes.
help roi	Print current ROI status and API entry points.
help journal	Print semantic GUI history controls.
help root	Print how to attach GRootInteract() in a normal ROOT session.

Mouse Commands

Input	Context	Action	Notes
Left click	1D or 2D histogram	Add a primary marker	Primary markers are generally limited to two.
Ctrl + left click	1D histogram	Add a fit marker	Four fit markers are used for double-Gaussian fitting. This depends on GCanvas event-state tracking.
Ctrl + left click	2D histogram	Add a cut marker	This depends on GCanvas event-state tracking.
Left click after starting 2D cut mode	2D histogram	Add another cut vertex	Once cut markers exist, ordinary clicks continue the cut.
Shift + left click	Histogram	Open a clean draw-copy in a new GCanvas	Copied helper objects such as markers and fits are removed from the copy.
Drag marker	Marker object	Move marker	Handled by GMarker::ExecuteEvent.
Drag existing TCutG	2D histogram cut	Let ROOT edit the cut	Existing cuts are left to ROOT's native interaction.

1D Histogram Keys

These commands operate on the current 1D histogram returned by GrabHist().

Key	Marker Requirement	Action	Notes
b	None	Show calculated background	GH1D only.
B	None	Toggle background display/removal state	GH1D only.
e	Two primary markers	Expand/zoom X range to the marker interval	Markers are removed after zooming.
f	Two primary markers	Run PhotoPeakFit() over the marker interval	Uses the photopeak fit model.
g	Two primary markers	Run GausFit() over the marker interval	Markers are removed after a successful fit.
g	Four fit markers	Run DoubleGausFit()	Fit markers are usually created with Ctrl + left click in GCanvas.
m	None	Remove markers	Removes all marker types on the histogram.
n	None	Clear fits, markers, residual state, sumw2, and shown peak markers	Does not delete the histogram.
o	None	Unzoom X axis	Restores the full X range.
q	None	Unbin by a factor of two	GH1D only; preserves the current viewed X range.
r	None	Toggle residual display	GH1D only. This is the current code behavior.
s	None	Show searched peaks	GH1D::ShowPeaks().
w	None	Rebin by a factor of two	GH1D only; preserves the current viewed X range.
l or z	None	Toggle log Y scale	Uses the current pad.

1D Projection Keys

These commands apply when the current 1D histogram is a GH1D projection with a GH2D parent.

Key	Marker Requirement	Action	Notes
c	Two primary markers	Store the marker interval as a background range	Only valid on a projection from a GH2D. Existing background markers are replaced.
p	Two primary markers	Project the parent matrix onto the opposite axis through the marker interval	If two background markers exist, the background projection is subtracted. Current subtraction is unscaled by gate width.

2D Histogram Keys

These commands operate on 2D histograms. Some require the histogram to be a GH2D; plain ROOT TH2 support is limited to ROOT-native behavior.

Key	Marker Requirement	Action	Notes
c	At least one primary marker	Convert primary markers into cut markers	Starts polygon cut-vertex mode.
e	Two primary markers	Expand/zoom X and Y ranges to the marker box	Markers are removed after zooming.
g	Cut markers	Build a TCutG from cut markers	The cut is named cutN, added to the histogram function list, and markers are removed.
m	None	Remove markers	Removes all marker types on the histogram.
n	None	Clear fits and markers	Also clears Sumw2.
o	None	Unzoom X and Y axes	Restores both axes.
x	None	Create and draw a full X projection in a new GCanvas	GH2D only. The projection remembers its parent.
X	None	Enable ROOT's TH2::SetShowProjectionX(1)	Works on any TH2.
y	None	Create and draw a full Y projection in a new GCanvas	GH2D only. The projection remembers its parent.
l or z	None	Toggle log Z scale	Uses the current pad.

GCanvas-Only Keys

These commands are handled by GCanvas, not by the GRootInteract() TExec alone.

Key	Context	Action	Notes
Space	Multi-pad canvas	Make the selected pad current and update pads	Useful after clicking between subpads.
Left arrow	1D histogram	Slide the viewed X range left by half a window	Shift or locked pads applies the slide to all histograms on the canvas.
Right arrow	1D histogram	Slide the viewed X range right by half a window	Shift or locked pads applies the slide to all histograms on the canvas.
Up arrow	1D projection from GH2D	Draw the next projection remembered by the parent GH2D	Projection-history navigation.
Down arrow	1D projection from GH2D	Draw the previous projection remembered by the parent GH2D	Projection-history navigation.

ROI Status

GROI currently exists as an object/API feature, not as a key-bound interactive mode. The current 1D keyboard workflow is fit-centered:

• g and f create fits from marker ranges.
• r toggles residual display for fit inspection.
• ROI creation/removal is available through GROI, GROI::CreateFromMarkers(), and GROI::RemoveAll().

GUI History

Interactive prompt input is already stored by ROOT in .gint_history. In addition, groot records semantic GUI actions to .gui_history by default. The file uses JSON Lines and is meant to describe meaningful analysis operations rather than raw mouse pixels. See GUI History for the full format, controls, and inspector commands.

Currently Unbound or Stubbed

Command	Status
Canvas ? key	Not currently bound in GCommands.cxx; use prompt ? or help.
R remove ROIs	Listed in older README text, but no current key binding was found in GCommands.cxx.
ROI creation key	Intentionally not bound in the current interaction mode. Use the GROI API directly for now.
Graph commands	GRootInteractGraph* functions currently return without doing meaningful work.