# Multiple segment
**URL:** https://discourse.slicer.org/t/multiple-segment/2493
**Category:** Development
**Created:** [April 2, 2018, 2:53pm UTC](https://discourse.slicer.org/t/multiple-segment/2493 "2018-04-02T14:53:35Z")
**Posts on this page:** 7
**Page:** 1
### Author:  [@anandmulay3](https://discourse.slicer.org/u/anandmulay3)
#### Post date: [April 2, 2018, 2:53pm UTC](https://discourse.slicer.org/t/multiple-segment/2493/1 "2018-04-02T14:53:35Z")
i’m adding 2nd segment under same masterNode, But whenever i try to apply effects on it’s getting applied on 1st segment only,
How to select 2nd segment as active segment???
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### Author:  [@cpinter](https://discourse.slicer.org/u/cpinter)
#### Post date: [April 2, 2018, 4:05pm UTC](https://discourse.slicer.org/t/multiple-segment/2493/2 "2018-04-02T16:05:23Z")
You need to select the second segment in the segment list. It’s always the highlighted one that is edited by the selected effect.
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### Author:  [@lassoan](https://discourse.slicer.org/u/lassoan)
#### Post date: [April 2, 2018, 5:23pm UTC](https://discourse.slicer.org/t/multiple-segment/2493/3 "2018-04-02T17:23:48Z")
Programmetically you can select a segment using [setCurrentSegmentID](http://apidocs.slicer.org/master/classqMRMLSegmentEditorWidget.html#a1537f275ab7571d8b330dfb5afdfe5ed) method of the segment editor widget.
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### Author:  [@anandmulay3](https://discourse.slicer.org/u/anandmulay3)
#### Post date: [April 3, 2018, 1:21pm UTC](https://discourse.slicer.org/t/multiple-segment/2493/4 "2018-04-03T13:21:55Z")
addsegID = segmentationNode.GetSegmentation().AddEmptySegment(“bone”)
segmentEditorWidget = slicer.qMRMLSegmentEditorWidget()
segmentEditorWidget.setMRMLScene(slicer.mrmlScene)
segmentEditorNode = slicer.mrmlScene.AddNewNodeByClass(“vtkMRMLSegmentEditorNode”)
segmentEditorWidget.setMRMLSegmentEditorNode(segmentEditorNode)
segmentEditorWidget.setSegmentationNode(segmentationNode)
segmentEditorWidget.setMasterVolumeNode(masterVolumeNode)
segmentEditorWidget.setCurrentSegmentID(‘addsegID’)
segmentEditorWidget.setActiveEffectByName(“Threshold”)
Traceback (most recent call last):
File “C:\Program Files\Slicer 4.9.0-2018-03-27\lib\Slicer-4.9\qt-scripted-modules\SegmentEditorEffects\SegmentEditorEffects\SegmentEditorThresholdEffect.py”, line 54, in activate
self.segment2DFillOpacity = displayNode.GetSegmentOpacity2DFill(segmentID)
TypeError: GetSegmentOpacity2DFill argument 1: string is required
i’m getting this error when i try to switch on 2nd segment to apply effect
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### Author:  [@cpinter](https://discourse.slicer.org/u/cpinter)
#### Post date: [April 3, 2018, 3:17pm UTC](https://discourse.slicer.org/t/multiple-segment/2493/5 "2018-04-03T15:17:49Z")
Based on the code snippet you posted there is no variable named `segmentID`, so getting the error is expected. You have one variable storing a segment ID called `addsegID`. Maybe you wanted to use that?
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### Author:  [@lassoan](https://discourse.slicer.org/u/lassoan)
#### Post date: [April 3, 2018, 10:23pm UTC](https://discourse.slicer.org/t/multiple-segment/2493/6 "2018-04-03T22:23:07Z")
> [@anandmulay3](#):
>
> segmentEditorWidget.setCurrentSegmentID(‘addsegID’)
Another issue is that here you probably wanted to set the string that is stored in addSegID variable, so the quotes around addSegID must be removed.
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### Author:  [@anandmulay3](https://discourse.slicer.org/u/anandmulay3)
#### Post date: [April 4, 2018, 7:42am UTC](https://discourse.slicer.org/t/multiple-segment/2493/7 "2018-04-04T07:42:44Z")
ohh yes that was the fault, thanks