[?] Plot all points with Show[ListPlot[data]]?

Questions
1

I have not been using Mathematica for some time. I did quite complex things in the past. But today I met a trivial one.

    data = {
                  {22.74, 26.45},
                  {22.91, 26.95},
                  {23.08, 29.20},
                  {23.13, 27.19},
                  {23.25, 26.60}
                  };

Show[ListPlot[data]]

How many point do you account on the plot ? I see only 4 points.
Now pls do (I update the y of the 3rd number):

data = {
               {22.74, 26.45},
               {22.91, 26.95},
               {23.08, 29.00}, 
               {23.13, 27.19},
               {23.25, 26.60}
               };
Show[ListPlot[data]]

In this case I see 5 points, the 3rd appears !!

Please let me again thrust this language.

2

Dear Ettore,

I cannot reproduce that problem.

data = {{22.74, 26.45}, {22.91, 26.95}, {23.08, 29.20}, {23.13, 27.19}, {23.25, 26.60}}; 
Show[ListPlot[data]]

gives

ScreenShot2017-08-10at16.46.57.png
ScreenShot2017-08-10at16.46.57.png752×478 8.62 KB

and I see all five points.

Cheers,

Marco

PS: What’s your OS and MMA version? You might want to try the PlotRange option:

Show[ListPlot[data,PlotRange->All]]
3

I see (on my system Mma 7) 5 points with both inputs.

What about

ListPlot[data, PlotRange -> {{22.5, 23.5}, {26, 30}}, PlotStyle -> PointSize[.03]]
4

Is there any chance that

Show[ListPlot[data], PlotRange -> All]

might make your problem go away?

5

Thank you, I use Mma 11.0 on a mac OS Sierra. It might be a rendering problem, but it’s impressive because the vertical scale is autoscaled as the point a Y 29.00 goes to 29.20 .

Anyhow, mysteriously, if I specifying the PlotRange (which indeed should be automated)

ListPlot.png
ListPlot.png1626×1548 68.5 KB

6

Ah. Then PlotRange was a good guess for the cause of this. The precise behavior of plotting, with or without PlotRange, has always been a little uncertain.