get alpha (color) value of a line

5 Ansichten (letzte 30 Tage)
Ali Hilo
Ali Hilo am 27 Sep. 2022
Kommentiert: Rik am 27 Sep. 2022
i need to copy a line to another plot, the copied line have alpha color value (Transperency / grey visibility) :
when drawing the line I use :
>> plot(...,'Color',[Color_Vect , Alpha],'LineWidth',10)
Color_Vect : vector of the colors i.e. [ 1 0 0] . Alpha =0.2.
in another section, when i need to copy the line to another plot I want to extract the alpha value of the line to add it to the new line.
I've been searching in all the values of the Line handles but couldnt find any aplha value.
do anyone knows were is this value stored ??
Thank you

Akzeptierte Antwort

Rik
Rik am 27 Sep. 2022
Bearbeitet: Rik am 27 Sep. 2022
I have no clue why this is hidden, but converting the object to a struct and hunting for a few appropriate candidates I found that h.Edge.ColorData was a 4x1 uint8.
h=plot(rand(1,10),1:10,'Color',[1 0 0 0.2],'LineWidth',10);
warning('off','MATLAB:structOnObject')
h_=struct(h);h_.Edge.ColorData ,close
Warning: The LineSmoothing property will be removed in a future release.
Warning: The EraseMode property is no longer supported and will error in a future release.
ans = 4×1
255 0 0 51
Note that this is undocumented, and may be specific to a release and/or OS. This works on my Windows copy, as well as online, but it might only work for R2022b, you'll have to test this on R2019a yourself. Just look for anything that might fit after converting the object to a struct.
  2 Kommentare
Ali Hilo
Ali Hilo am 27 Sep. 2022
thank you Rik, it's working now and i can extract this value
Rik
Rik am 27 Sep. 2022
You're welcome.
I did a quick test, and it appears this works on R2020b and later (at least on Windows).

Melden Sie sich an, um zu kommentieren.

Weitere Antworten (0)

Kategorien

Mehr zu Graphics finden Sie in Help Center und File Exchange

Produkte


Version

R2019a

Community Treasure Hunt

Find the treasures in MATLAB Central and discover how the community can help you!

Start Hunting!

Translated by