How to use scatter with transparent dots?

facealpha is not working for me

[KSSV]

Show the code..which you tried.

Answer 1

[Adam Danz]

MarkerFaceAlpha and MarkerEdgeAlpha are what you're looking for. Check out this example.

https://www.mathworks.com/examples/matlab/mw/graphics-ex36949892-create-scatter-chart-with-transparency

[from the link]

x = [5 10 11 13 18];
y1 = [40 80 150 80 50];
a1 = 100*[100 50 80 30 50];
scatter(x,y1,a1,'MarkerFaceColor','b','MarkerEdgeColor','b',...
    'MarkerFaceAlpha',.2,'MarkerEdgeAlpha',.2)
axis([0 20 0 200])
x = [2 6 8 11 13];
y2 = [30 40 100 60 140];
a2 = 100*[30 50 30 80 80];
hold on
scatter(x,y2,a2,'MarkerFaceColor','r','MarkerEdgeColor','r',...
    'MarkerFaceAlpha',.2,'MarkerEdgeAlpha',.2)
hold off

[Craig Puetz]

I am trying this with v2020b and it simply doesn't work - no combination of parameters makes the markers transparent.

Goal:

1) Plot a group of points on a geoaxis with a 3rd dataset that varies in color: Working

2) Plot two additional groups of points with the areas covered in a lightly tinted "blob": Not working, blob is full intensity, not transparent

Code:

f1 = figure(1);
clf;
gx1 = geoaxes;
geobasemap satellite
hold on
std_scaled = paawDF.std_Alt/(max(paawDF.std_Alt)-min(paawDF.std_Alt));
h1 = scatter(gx1,paawDF.lat_dd,paawDF.lon_dd,20,std_scaled,"filled");
h2 = scatter(gx1,decBigData.Latitude(taFilter),decBigData.Longitude(taFilter),5,"filled", ...
    "Marker", 'o', ...
    "MarkerFaceColor", [0 1 0],"MarkerEdgeColor",'none', ...
    "MarkerFaceAlpha", .3, "MarkerEdgeAlpha", .3);
% param
% set(h2.MarkerHandle, 'FaceColorType','truecoloralpha', 'FaceColorData',uint8([0;200;0; 50]));

% h2 = plot(gx1,decBigData.Latitude(taFilter),decBigData.Longitude(taFilter),'o','Color',[0 1 0 0.2]);
h3 = plot(gx1,decBigDataWheel.Latitude(taFilterWheel),decBigDataWheel.Longitude(taFilterWheel),'.r');
% h2.MarkerFaceAlpha = .2;
% h2.MarkerEdgeAlpha = .2;
% h3.MarkerFaceAlpha = .2;
% h3.MarkerEdgeAlpha = .2;

Obviously, I have not run all of these settings at the same time, those commented out are other things I have tried.

All comments are welcome!

[Image Analyst]

@Craig Puetz ok what you tried did not work. (I can't try it because I don't have the Mapping Toolbox.) But does @Adam Danz's original code work for you?

[Adam Danz]

Moving @Craig Puetz's answer here

----------------------------------------------------

I went back and ran the original code (took me a minute to remember what this was even about!).

@Adam Danz Your code works properly and produces exactly the image shown in this example. I don't know why similiar commands don't produce similiar results in my example with the Mapping toolbox.

[Adam Danz]

@Craig Puetz, we can't run your code without having the data (ie, paawDF, ect). Have you tried using geoscatter and geoplot instead of scatter and plot?

[Jacek Wodecki]

markerfacealpha and markeredgealpha is not doing anything, Matlab 2021b. Anyone else?

[Damon Bradley]

Depends on the marker you use. If you use a dot '.', you will not see any result. With other markers, you will. I've done this on R2020a though, so please double-check with your rev. Good luck!

[Benjamin]

@Damon Bradley, thank you! Would have been confused for a long time without this post.