Indicators
While evaluating some experimental data, some live indicators comes handy
Crossbar and coordinates field
If you are an Origin Pro user, this one is an essential tool for picking data points from your graph.
Essentially we need two things Line and TextView
Normal way
point = {0.,0.};
(* plot some dummy function *)
Plot[Sinc[x], {x,-10,10}, Epilog->{
Red,
(* crossbar *)
Line[With[{p = point[[1]]},
{{p, -10}, {p, 10}}
] // Offload],
Line[With[{p = point[[2]]},
{{-10, p}, {10, p}}
] // Offload],
(* attach listener *)
EventHandler[Graphics`Canvas[], {
"mousemove" -> Function[xy, point = xy]
}]
}]
It attaches an EventHandler
to a Graphics`Canvas[]
object. Every-time user moves a mouse over it, an event handler is fired and point
symbol is updated, that causes updates of all lines
You can reduce the lag by tuning TransitionDuration to a lower value.
Now the text field
TextView[point // Offload]
An accuracy might be too large. We can output there separately by using another variable or a symbol
point = {0.,0.};
text = " ";
(* plot some dummy function *)
Plot[Sinc[x], {x,-10,10}, Epilog->{
Red,
(* crossbar *)
Line[With[{p = point[[1]]},
{{p, -10}, {p, 10}}
] // Offload],
Line[With[{p = point[[2]]},
{{-10, p}, {10, p}}
] // Offload],
EventHandler[Graphics`Canvas[], {
"mousemove" -> Function[xy,
point = xy;
text = ToString[Round[xy, 0.01]];
]
}]
}]
TextView[text // Offload]
Now it is much better
Dynamically append to a plot
One can also append it to a plot dynamically afterwards using MetaMarker. Sometimes it is better, since all variables are scoped
placeCrossbar[meta_String, pos_:{0.,0.}] := LeakyModule[{point = pos, text = ""},
FrontSubmit[{
Red,
(* crossbar *)
Line[With[{p = point[[1]]},
{{p, -10}, {p, 10}}
] // Offload],
Line[With[{p = point[[2]]},
{{-10, p}, {10, p}}
] // Offload],
EventHandler[Graphics`Canvas[], {
"mousemove" -> Function[xy,
point = xy;
text = ToString[Round[xy, 0.01]];
]
}]
}, MetaMarker[meta]];
TextView[text // Offload]
]
Now the only thing we need is to scope
(* plot some dummy function *)
Plot[Sinc[x], {x,-10,10}, Epilog->{MetaMarker["plt"]}]
and after evaluation we can append it
placeCrossbar["plt"]
Progress bar
During a long evaluation process we need some sort of indication. For this thing we need a couple of ingredients: Rectangle, CellPrint
One can think about it if it was a typical OOP. We need a constructor that returns an instance for tracking the evaluation progress
progressBar[max_Real | max_Integer] := LeakyModule[{
progress = 0.,
bar,
increment,
timer = AbsoluteTime[]
},
bar = CellPrint[ToString[
Graphics[{
LightBlue, Rectangle[{-1,-1}, {1,1}],
Green, Rectangle[{-1,-1}, {Offload[2 progress - 1], 1}]
}, ImagePadding->None, ImageSize->{400, 30}]
, StandardForm], "After"->EvaluationCell[]];
(* throttling *)
increment[value_Real | value_Integer] := If[AbsoluteTime[] - timer > 0.1,
timer = AbsoluteTime[];
progress = value / max // N;
If[progress >= 0.99,
ClearAll[increment];
Delete[bar];
];
];
increment
]
here we also use sort of throttling not to overstress frontend if our progress tracking function is called too often. A progress bar itself is printed to another cell as basically a growing green rectangle.
Let us try to use it
bar = progressBar[10];
Table[bar[i]; Pause[0.5]; i, {i, 10}]