I’m relearning GIS after a ten year gap and, just like when I first learnt it, it’s doing things randomly that I can’t solve. Google hasn’t thrown up any answers. I’m trying to do some interpolation in QGIS 3.1- I did it yesterday following the instructions in this video –

Now, two days later, it won’t play ball. I do the interpolation and either there’s no output or a single colour output using an average value of the data I’m interpolating between.

Here’s what I’m doing-

1- I have five data points showing levels of an element in groundwater. I want an interpolation between them.

[url=https://flic.kr/p/2id1q14]1[/url] by Luke Bradley, on Flickr

2- Here’s the attribute table for the field-

[url=https://flic.kr/p/2id2tYd]2[/url] by Luke Bradley, on Flickr

3- Here’s what I’ve put into the IDW Interpolation box-

[url=https://flic.kr/p/2icY3nk]3[/url] by Luke Bradley, on Flickr

4 – The output interpolation layer only has a single value. Changing this value in the Style dialog box doesn’t do anything – the interpolation visualisation doesn’t display.

[url=https://flic.kr/p/2icY3mP]4[/url] by Luke Bradley, on Flickr

5 – Here’s what my map looks like after I’ve run the interpolation. Nothing.

[url=https://flic.kr/p/2icY3md]5[/url] by Luke Bradley, on Flickr

If I run it using Layer Extent as the area – a black square (using singleband grey for the style) –

[url=https://flic.kr/p/2id2FgP]6[/url] by Luke Bradley, on Flickr

What am I doing wrong? I’ve not changed anything from when I ran this on Wednesday and got a lovely colourful display using singleband pseudocolour.

Is the CRS of your map layer set to EPSG:27700 (bottom right next to Render)

Is it because value 5 is selected in the attribute table?

Oooh a nice juicy contaminated site.

Dye works?

What have you changed?

Reimported the points?

Altered the CSV?

I don’t have an answer, but I applaud your ability to beautifully form a question.

Is it pronounced jizz???

Bit of a wild card, but are you using the same monitor? It shouldn’t affect the generation of the output raster, but I wouldn’t rule it out.

It’s not a display issue, the black raster generated is because the pixels all have the same value.

In screenshot 4 you can see the min and max of the Raster displayed under the layer (505.002 and 505.002)

I don’t have quite the same version of QGIS, but it should just be as simple as following the steps the OP has included.

Does the log window shed any light?