# Cast/Create DisplacementField Python
**URL:** https://discourse.itk.org/t/cast-create-displacementfield-python/2610
**Category:** Beginner Questions
**Created:** [January 12, 2020, 9:29am UTC](https://discourse.itk.org/t/cast-create-displacementfield-python/2610 "2020-01-12T09:29:28Z")
**Posts on this page:** 3
**Page:** 1
### Author:  [@SiPyWiFi](https://discourse.itk.org/u/SiPyWiFi)
#### Post date: [January 12, 2020, 9:29am UTC](https://discourse.itk.org/t/cast-create-displacementfield-python/2610/1 "2020-01-12T09:29:28Z")
Dear All!
I have only been using ITK for a short time.
In my project the goal is to transform an input image with a displacement field.
For this I want to use the Python version.
My problems is/are (They are linked):
a) I cannot create the displacement field with the data type i want.
b) I cannot change the datatype of the displacement field.
I created a Displacement field with the following code:
field = itk.DisplacementFieldTransform[itk.D, 2].New()
a)
Double is the only allowed data type (-\> checked it with itk.DisplacementFieldTransform.GetOutputs()).
I think my problem would be solved if the function would allow other data types.
* * *
To transform the image i followed the example:
[https://itk.org/ITKExamples/src/Filtering/ImageGrid/WarpAnImageUsingADeformationField/Documentation.html](https://itk.org/ITKExamples/src/Filtering/ImageGrid/WarpAnImageUsingADeformationField/Documentation.html)
b)
To cast the displacement field to the right data type I wanted to use itk.CastImageFilter.
Because the C++ Function Itk.VectorCastImageFilter is not implemented in ITK python.
Which results in the Error:
"itk.CastImageFilter is not wrapped for input type `itk.Image[itk.Vector[itk.D,2],2], itk.Image[itk.Vector[itk.F,2],2]`"
Summary:
itk.WarpImageFilter needs itk.Image[itk.Vector[itk.F,2],2] -\> I can only create itk.Image[itk.Vector[itk.D,2],2] -\> I havenot managed to cast it to the right dtype.
What can I do?
Best Regards Simon
---
### Author:  [@matt.mccormick](https://discourse.itk.org/u/matt.mccormick)
#### Post date: [January 12, 2020, 5:53pm UTC](https://discourse.itk.org/t/cast-create-displacementfield-python/2610/2 "2020-01-12T17:53:29Z")
Hello Simon!
Welcome to the ITK community! 🌞
Good questions.
`itk.Vector[itk.D, Dimension]` support is currently missing in the binary ITK Python packages – we will add it to the ITK 5.1 RC 2 release. Then, the displacement field image can be read with `itk.imread` or `itk.ImageFileReader`, or cast with `itk.cast_image_filter`. The transform can then be set up with
```auto
transform = itk.DisplacementFieldTransform[itk.D, 2].New()
# field is the itk.Image[itk.Vector[itk.D, 2]
transform.SetDisplacementField(field)
```
---
### Author:  [@SiPyWiFi](https://discourse.itk.org/u/SiPyWiFi)
#### Post date: [March 20, 2020, 1:41pm UTC](https://discourse.itk.org/t/cast-create-displacementfield-python/2610/3 "2020-03-20T13:41:40Z")
Hi,
thank you for adding it to the new release!
This is my solution, if anyone else has the same problem:
```
VectorDimension = 3
PixelType = itk.Vector[itk.F, VectorDimension]
ImageDimension = 3
ImageType = itk.Image[PixelType, ImageDimension]
DisplacementFieldNumpy = np.zeros((100, 100, 100, 3)).astype(np.float32)
PyBuffer = itk.PyBuffer[ImageType]
VectorImage = PyBuffer.GetImageFromArray(displacementField)
```
Best Regards
Simon