Question

Version 8.04 on windows.

I noticed that when I have 2 data sets and use ListPlot on them, that the points shown do not follow the color specified by PlotStyle setting for the line color itself when using Joined->True.

I just to see if may be I am not understanding the meaning of PlotStyle here.

Here is an example:

data1 = {{1, 1}, {2, 1.5}, {3, 2}};
data2 = {{1, 1.5}, {2, 2.5}, {3, 3}};
ListPlot[{data1, data2}, PlotStyle -> {Red, Blue}, Joined -> False, 
 Mesh -> All, AxesOrigin -> {0, 0}]

Notice that the points have the colors set correctly according to PlotStyle (red then blue).

Now when I add Joined->True, see what happens:

data1 = {{1, 1}, {2, 1.5}, {3, 2}};
data2 = {{1, 1.5}, {2, 2.5}, {3, 3}};
ListPlot[{data1, data2}, PlotStyle -> {Red, Blue}, Joined -> True, 
 Mesh -> All, AxesOrigin -> {0, 0}]

Now the points on the top line, which is blue have changed color to red, which is the color of the bottom line points!.

Does this make sense?

One way to overcome this is by explicitly adding PlotMarkers to give the colors to the points, like this:

data1 = {{1, 1}, {2, 1.5}, {3, 2}};
data2 = {{1, 1.5}, {2, 2.5}, {3, 3}};
ListPlot[{data1, data2}, PlotStyle -> {Red, Blue}, Joined -> True, 
 Mesh -> All, AxesOrigin -> {0, 0}, 
 PlotMarkers -> {{Graphics[{Red, Point[{0, 0}]}], 
    12}, {Graphics[{Blue, Point[{0, 0}]}], 12}}]

Question: Why the points change color to red in the top line (second plot above) ? and is there a simpler solution to this that what I did above?

edit(1)

trying MeshStyle -> {Red, Blue} seems to mix things also:

data1 = {{1, 1}, {2, 1.5}, {3, 2}};
data2 = {{1, 1.5}, {2, 2.5}, {3, 3}};
ListPlot[{data1, data2}, PlotStyle -> {Red, Blue}, Joined -> True, 
 AxesOrigin -> {0, 0}, Mesh -> All, MeshStyle -> {Red, Blue}]

thanks

Answer 1

I think it’s the Mesh->All which is messing things up. You can either specify the MeshStyle or just leave it off, and set PlotMarkers->Automatic.

ListPlot[{data1,data2},PlotStyle->{Red,Blue},Joined->True,
 PlotMarkers->Automatic,AxesOrigin->{0,0}]