Problem with LogarithmicAxisValueConverter() and Zoom

Hi all,

I have a cartesian graphic where I put a checkBox called "Log Scale". When is checked, I convert XAxis and YAxis to a logarithmic axis using the function below:

chart.XAxis.ValueConverter = new LogarithmicAxisValueConverter(); chart.YAxis.ValueConverter = new LogarithmicAxisValueConverter();

After this action, when I try to use a Zoom Mode, my graphic disappear. I'm probably doing something wrong.

Anyone have an idea?

Best regards, Raphaela.

Hello Raphaela

This may be a bug in the chart control, but I have not been able to reproduce this issue. Could you please send a project that I can use to reproduce the issue, then I'll fix this up for you.

Jason Fauchelle

Hi Jason !

I forgot to tell you that I work in Petrobras together with Jean Phillipe Francois, and I´m starting to use Mindscape.

I updated my Mindscape version to nightly build (October 25) and the problem disappear !!! May be this was a bug of the older version....

But I have some doubts:

1) It's possible to add a checkBoxColumn into a data grid?

2) It´s possible to change the caption of the ms:ZoomMode property ? I would like to have the options in another language....

3) Can I select a range of points in a scatter chart? Do you have any example ?

4) I saw that is possible to use chart events to listen mouse movement. In Mindscape samples it´s possible to use mouse events to get the position of mouse pointer. I would like to use this event to get a point value in a scatter chart. It's possible?

Best regards, Raphaela.

Hello Raphaela

1) The best way to set up a check box column is to add a PropertyEditor to the Editors collection of the DataGrid. Here is an example of this which will hookup the check boxes to the IsChecked property of the underlying row model objects. Make sure you also either set AutoGenerateColumns to True, or add a DataGridColumn to the DataGrid with the PropertyName set to the property you want it to bind to ("IsChecked" in this example).

<ms:DataGrid>
  <ms:DataGrid.Editors>
    <ms:PropertyEditor PropertyName="IsChecked" EditorTemplate="{StaticResource {x:Static ms:PropertyGrid.CheckBoxEditorKey}}" />
  </ms:DataGrid.Editors>
</ms:DataGrid>

2) The easiest way to do this would be to fill the ComboBox with strings instead of the ZoomMode enums. The strings would be the values you want to be displayed. Then on the SelectedItem binding on the ComboBox, you could implement an IValueConverter that converts back and forth between the ZoomMode enum values and the string values.

3) Currently the only way to select multiple scatter points is to set SelectionMode to Multiple. Then the user can select multiple points, but only by clicking on one point at a time. If you mean to create a rectangle that you can drag that selects multiple points, you could implement this by using the chart events and a custom foreground element. Or if you mean to hold down a key such as Shift and then click a point to select a range, you'd be able to implement this by listening to selection changed events.

4) Do you mean to find which data symbol the mouse is over? If so, this can not be done using the events you are referring to. Let me know the behavior you want to implement and I'll see what the best way would be. A picture of the result you want may also help.

Let me know if you have further questions about any of this.

Jason Fauchelle

Jason,

Thank you so much for your tips. I'll try to implement them and if I have any problem, I contact you.

About my question number 4, I think I wasn't very clear. I'll try to explain again. Today, when we plot a scatter chart, It's possible to click in a point of the graphic. I would like to know how can we get the value of this point to show in a label... Or, if it's possible to pass the mouse over the point and see it's value.

Best regards, Raphaela.

Hello Raphaela

If you want a label to display on mouse over, the easiest way would be to use a ToolTip. We provide a simple way of setting this up by setting the ToolTipBinding property of a ScatterSeries. For example if you set ToolTipBinding="{Binding}", putting the mouse over a point will cause a tooltip to display the ToString value of your data points. If you are using custom data implementations, you can override the ToString method to return what you want, or use a converter in the binding.

If you want a label to be displayed when the point is clicked, you can do this by creating a custom scatter point style. In this style, include the visual for a label such as a border containing a TextBlock binding to the data context of the chart symbol. By default this label would be hidden, and could be made visible by a trigger listening to the selected state of the chart symbol. Positioning the label could be tricky.

I recommend going with the tooltip approach as it is easiest to implement and is more commonly used.

Jason Fauchelle