# Updating Filters of Live Programmable Sources on New Data

**URL:** https://discourse.paraview.org/t/updating-filters-of-live-programmable-sources-on-new-data/2959
**Category:** ParaView Support
**Tags:** python
**Created:** [November 12, 2019, 1:31am UTC](https://discourse.paraview.org/t/updating-filters-of-live-programmable-sources-on-new-data/2959 "2019-11-12T01:31:46Z")
**Posts on this page:** 2
**Page:** 1

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### Author: ![misho88](https://discourse.paraview.org/user_avatar/discourse.paraview.org/misho88/32/2364_2.png) [@misho88](https://discourse.paraview.org/u/misho88)
#### Post date: [November 12, 2019, 1:31am UTC](https://discourse.paraview.org/t/updating-filters-of-live-programmable-sources-on-new-data/2959/1 "2019-11-12T01:31:46Z")

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I don’t know how to get the rest of a pipeline to update in response to a Live Programmable Source changing its output. For example, let’s say I add such a source that outputs a vtkTable with a simple script:

```
from numpy.random import randn
output.RowData.append(randn(50), 'noise')

```

and make it always update with CheckNeedsUpdate script set to:

```
self.SetNeedsUpdate(True)

```

If any of this up to here is not how I’m meant to use the Live Programmable Source, please do let me know, but this part more or less works as I want it to, other than the fact that I can’t seem to change the update interval.

Now, let’s say I add a filter to it, like Extract Selection, and plot it. The filter will only update when I move my mouse across the plot rather than when the source data changes. Is there some way to do this? What if I have something more flexible like a programmable filter?

If the answer to the above questions is ‘no’, is there something I can enter into the Python Shell to force an update on demand?

Thanks in advance for any help!

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### Author: ![nicolas.vuaille](https://discourse.paraview.org/user_avatar/discourse.paraview.org/nicolas.vuaille/32/5873_2.png) [@nicolas.vuaille](https://discourse.paraview.org/u/nicolas.vuaille)
#### Post date: [December 23, 2019, 10:30am UTC](https://discourse.paraview.org/t/updating-filters-of-live-programmable-sources-on-new-data/2959/2 "2019-12-23T10:30:41Z")

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Mainly, if a source is updated, views should also be updated … I opened a bug report ([https://gitlab.kitware.com/paraview/paraview/issues/19553](https://gitlab.kitware.com/paraview/paraview/issues/19553)).

In the python shell, you can use the command `Update()` on the choosen view. (see `GetActiveView()` and `GetViews()`)

Concerning the update interval, you can add a python attribute on the live source to compare with current time and update each n seconds. See this thread : [update automatic data input](https://discourse.paraview.org/t/update-automatic-data-input/3222/2)