[vtkusers] vtkChartLegend Position in Python

[Cory Quammen]

On Thu, Oct 8, 2015 at 3:58 PM, Slaughter, Andrew E <
andrew.slaughter at inl.gov> wrote:

>
> On Thu, Oct 8, 2015 at 1:27 PM, Cory Quammen <cory.quammen at kitware.com>
> wrote:
>
>> Well shoot, that member function must not be wrapped.
>>
>> Instead, try this
>>
>> legend = chart.GetLegend()
>> legend.SetHorizontalAlignment(vtk.vtkChartLegend.CUSTOM)
>> legend.SetVerticalAlignment(vtk.vtkChartLegend.CUSTOM)
>> legend.SetPoint(0, 20)
>>
>
> This causes the legend to move to the lower left in the window, SetPoint
> does nothing.
>

(0, 20) is in the lower left of the window. Try with SetPoint(200, 200),
for example. The legend should be in the upper right.


> Using the Set(Horizontal/Vertical)Alignment methods move the legend to the
> various points within the
> plot window. For example, the following places it where I was hoping to
> move the legend.
> legend.SetHorizontalAlignment(vtk.vtkChartLegend.LEFT)
> legend.SetVerticalAlignment(vtk.vtkChartLegend.TOP)
>
> However, this SetPoint method does not seem to change anything. Perhaps I
> am just not understanding how the bounding box works for the object. I was
> thinking that SetPoint would locate the corner of the legend box at the
> specified point and that the Set(Horizontal/Vertical)Alignment methods
> indicate how this box aligns to the point.
>
> The behavior seems to be that the legend has a bounding box equal to the
> chart axis dimensions and that the alignment methods alter the placement of
> the legend box within this larger bounding box.
>

Yes, the alignment refers to placement within the chart, not the alignment
of the legend with respect to the position.

- Cory


>
>
>>
> HTH,
>> Cory
>>
>>
>> On Thu, Oct 8, 2015 at 3:00 PM, Slaughter, Andrew E <
>> andrew.slaughter at inl.gov> wrote:
>>
>>> Yes, that function does not exist.
>>>
>>> On Thu, Oct 8, 2015 at 12:45 PM, Cory Quammen <cory.quammen at kitware.com>
>>> wrote:
>>>
>>>> Hi Andrew,
>>>>
>>>> Have you tried vtkChartXY::SetLegendPosition(const vtkRectf & rect),
>>>> e.g.
>>>>
>>>> rect = vtkRectf(0, 20, ?, ?)
>>>> char.SetLegendPosition(rect)
>>>>
>>>> HTH,
>>>> Cory
>>>>
>>>> On Thu, Oct 8, 2015 at 2:33 PM, Slaughter, Andrew E <
>>>> andrew.slaughter at inl.gov> wrote:
>>>>
>>>>> I am writing a script to build some line charts in VTK, but I am
>>>>> having difficulty repositioning a vtkChartLegend object.
>>>>>
>>>>> The python script below will create a plot. I would like to reposition
>>>>> the legend to the upper left-hand side of the chart so as to not interfere
>>>>> with the line plot. However, I am not able to make the legend move. I would
>>>>> appreciate any help to get the legend to re-position?
>>>>>
>>>>> I am running OSX (Yosemite) with Python 2.7.6 and VTK 6.3.
>>>>>
>>>>>
>>>>> #!/usr/bin/env python
>>>>> import vtk
>>>>>
>>>>> # Num. points
>>>>> n = 10
>>>>>
>>>>> # Create some data
>>>>> x = vtk.vtkFloatArray()
>>>>> y = vtk.vtkFloatArray()
>>>>> x.SetNumberOfTuples(n)
>>>>> x.SetName('x')
>>>>> y.SetNumberOfTuples(n)
>>>>> y.SetName('y')
>>>>>
>>>>> for i in range(10):
>>>>>     x.SetValue(i, float(i))
>>>>>     y.SetValue(i, float(2*i))
>>>>>
>>>>> # Create the table and line
>>>>> table = vtk.vtkTable()
>>>>> table.AddColumn(x)
>>>>> table.AddColumn(y)
>>>>> line = vtk.vtkPlotLine()
>>>>> line.SetInputData(table, 0, 1)
>>>>>
>>>>> # Create chart
>>>>> chart = vtk.vtkChartXY()
>>>>> chart.AddPlot(line)
>>>>>
>>>>> # Create view
>>>>> view = vtk.vtkContextActor()
>>>>> view.GetScene().AddItem(chart)
>>>>>
>>>>> # Renderer
>>>>> renderer = vtk.vtkRenderer()
>>>>> renderer.SetBackground(1,1,1)
>>>>> renderer.AddViewProp(view)
>>>>>
>>>>> # Legend
>>>>> chart.SetShowLegend(True)
>>>>> legend = chart.GetLegend()
>>>>> legend.SetPoint(0, 20) # This doesn't seem to do anything
>>>>>
>>>>> # Window
>>>>> window = vtk.vtkRenderWindow()
>>>>> window.AddRenderer(renderer)
>>>>>
>>>>> # Interactor
>>>>> interactor = vtk.vtkRenderWindowInteractor()
>>>>> interactor.SetRenderWindow(window)
>>>>>
>>>>> # Render
>>>>> window.Render()
>>>>> renderer.Render()
>>>>> interactor.Start()
>>>>>
>>>>> _______________________________________________
>>>>> Powered by www.kitware.com
>>>>>
>>>>> Visit other Kitware open-source projects at
>>>>> http://www.kitware.com/opensource/opensource.html
>>>>>
>>>>> Please keep messages on-topic and check the VTK FAQ at:
>>>>> http://www.vtk.org/Wiki/VTK_FAQ
>>>>>
>>>>> Search the list archives at: http://markmail.org/search/?q=vtkusers
>>>>>
>>>>> Follow this link to subscribe/unsubscribe:
>>>>> http://public.kitware.com/mailman/listinfo/vtkusers
>>>>>
>>>>>
>>>>
>>>>
>>>> --
>>>> Cory Quammen
>>>> R&D Engineer
>>>> Kitware, Inc.
>>>>
>>>
>>>
>>
>>
>> --
>> Cory Quammen
>> R&D Engineer
>> Kitware, Inc.
>>
>
>


-- 
Cory Quammen
R&D Engineer
Kitware, Inc.
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://public.kitware.com/pipermail/vtkusers/attachments/20151008/678ee7d5/attachment.html>