DynamicMap hover features displays fictional data values

HoloViews
1

I’ve recently been learning HoloViews, and while digging into an unexpected output I noticed that my DynamicMap is displaying fictional data values at the pixel level. I’ve got a DEM (raster dataset), which I read into an XArray and then plot using hvplot.image. If I open the same DEM in QGIS and zoom in to identical pixels of each, I get different height values for that pixel. If I search for those pixel values in the underlying XArray DataSet, I can find the QGIS height but not the HoloViews height. What’s happening (during rendering?) to make this happen, and is there a way to force it to return exact pixel values in the info/hover?

2

Hello, are the hover values of this small example fine to you?

import xarray as xr
import hvplot.xarray

da = xr.DataArray([[1,2],[3,4]],coords=dict(x=range(2),y=range(2)),dims=['y','x'])
ds = xr.Dataset(dict(value=da))
ds.hvplot.image('x','y').opts(colorbar=False)

If so, is your dataset as simple as that in its structure?

3

Thanks @marcbernot! The hover values in this small example work fine.

I think my data are similar in structure (x, y, and z), though less simple because it’s a much larger dataset and x, y, and z are floats (x and y have a 50m resolution geospatially).

I just found out about this issue, which could explain it…