0

I have a file with data fields which I have imported as CSV. When I look at the Field Attribute Table, the empty fields appear clearly as NULL values. However when I interpolate the data, the NULL values are being tenter image description herereated as 0 (zero).

How do I get around that?

  • Which interpolation tool are you using? – ndawson May 9 '18 at 20:48
  • I have used IDW interploation – Jordaan Fouche May 10 '18 at 12:42
1

You could try to filter your data (in layer properties > source > Query Builder with the expression : "MY_FIELD" is not NULL) to remove the null value before interpolating

  • Thank you. That really worked for me. But I find it counter intuitive. I expected the interpolation routine to honor the null values as NULL. I am new to QGIS. – Jordaan Fouche May 10 '18 at 13:11

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.