FillingStyle Thickness Distorting ListPlot image

Question

I'm trying to create a histogram using ListPlot using the Filling->Axis and FillingStyle -> {{LightGray, Thickness[.1]}} as options. However, when I use this the columns are actually higher than the value in the lists. Below is an example

   n = 6;
   p = 0.5;
   (*calculate probabilities *)
   list = Table[
     c = Binomial[n, k];
     d = p^k (1 - p)^(n - k);
     {k, c* d}, {k, 0, n}]


   (*FillingStyle Thickness results in additional height being added to \
   top of each column*)
   ListPlot[(list), 
    Joined -> False,
    Axes -> True,
    FrameTicks -> {Table[i, {i, 0 , n, 1}], 
      Table[i, {i, 0, 0.3, 0.05}]},
    FrameLabel -> {"Successes k", "Probability"},
    Frame -> {True, True, False, False},
    PlotStyle -> Automatic,
    Filling -> Axis,
    FillingStyle -> {{LightGray, Thickness[.1]}},
    ImageSize -> 6*72 ]

Does anyone have a suggestion for a solution for this problem while still using ListPlot?

Thanks,

Mike

Answer 1

This can be controlled by CapForm

ListPlot[(list), Joined -> False, 
 FrameTicks -> {Table[i, {i, 0, n, 1}], Table[i, {i, 0, 0.3, 0.05}]}, 
 FrameLabel -> {"Successes k", "Probability"}, 
 Frame -> {True, True, False, False}, PlotStyle -> Automatic, 
 Filling -> Bottom, 
 PlotRangePadding -> {Automatic, {None, Automatic}}, 
 FillingStyle -> {{LightGray, Thickness[.1], CapForm[None]}}, 
 ImageSize -> 6*72]

Answer 2

BarChart[Labeled[#2, #1] & @@@ list]

Answer 3

As you figured out, the Thickness command applies to the width of the Filling line in both the horizontal and vertical directions. I don't see how to make the boxes wider without also increasing their maximum height.

Here is a quick and dirty way to get what you want:

ListPlot[Flatten[
  Table[{list[[n, 1]] + dx, list[[n, 2]]}, {n, 
    Length[list]}, {dx, -.2, .2, .001}], 1], Filling -> Axis, 
 FillingStyle -> Directive[LightGray, Thickness[.001]], 
 PlotStyle -> None, Epilog -> First@ListPlot[list]]

Edit: This is a better way to get what you are looking for.

    dx = 0.2; (*half width of the rectangles *)
Show[Table[
  Graphics[{LightGray, 
    Rectangle[{list[[n, 1]] - dx, 0}, {list[[n, 1]] + dx, 
      list[[n, 2]]}]}], {n, Length[list]}], ListPlot[(list)], 
 PlotRange -> {0, All}, 
 FrameTicks -> {Table[i, {i, 0, n, 1}], Table[i, {i, 0, 0.3, 0.05}]}, 
 FrameLabel -> {"Successes k", "Probability"}, 
 Frame -> {True, True, False, False}, AspectRatio -> .6, 
 ImageSize -> 6*72]

(Although, as belisarius pointed out, you can use BarChart to get what you want, but you'll need to fiddle around with it to get better looking results).

Answer 4

I think you need to make some compromise for creating histogram by using ListPlot...I would suggest...

PlotStyle ->PointSize[Large],
Filling -> Axis,
FillingStyle -> {{LightGray, {Thickness[.025]}}}

Or use barchart