# Sample1d: don't eliminate duplicate values **URL:** \ **Category:** Q&A\ **Tags:** gmt\ **Created:** [August 11, 2021, 6:50am UTC](https://forum.generic-mapping-tools.org/t/sample1d-dont-eliminate-duplicate-values/1976 "2021-08-11T06:50:10Z")\ **Posts on this page:** 5\ **Page:** 1
**Author:** ![mjh217](https://avatars.discourse-cdn.com/v4/letter/m/bc8723/32.png) [@mjh217](https://forum.generic-mapping-tools.org/u/mjh217)\ **Post date:** [August 11, 2021, 6:50am UTC](https://forum.generic-mapping-tools.org/t/sample1d-dont-eliminate-duplicate-values/1976/1 "2021-08-11T06:50:10Z")
Hi all, I recently updated to gmt 6.2.0 from 6.1.0 and am having trouble with one of the updates to sample1d. Originally, if I had a look-up table (lookup.xy) like this: 0 00 1 10 2 20 And sampled it at these points (sample.x): 0.5 1.5 1.9 1.5 Using “gmt sample1d -Fl -Tsample.x lookup.xy” would return: 0.5 5 1.5 15 1.9 19 1.5 15 But the updated version gives: sample1d [WARNING]: Eliminated 1 duplicate values from the sorted array 0.5 5 1.5 15 1.9 19 I understand from this thread ([Sample1d on gmt6.1 and gmt6.2](https://flint.soest.hawaii.edu/t/sample1d-on-gmt6-1-and-gmt6-2/830/5)) why this update was made, but is there a way to not skip the duplicates? Often I am stripping columns from a data file, using sample1d to find a corresponding value, and pasting things back together, which now doesn’t work when there happen to be duplicate values due to the rows no longer corresponding. Or am I using the wrong tool for the job? Also, has a sorting procedure been added, such that the points are not necessarily returned in their original order? Thanks a lot for your help! ---
**Author:** ![pwessel](https://yyz1.discourse-cdn.com/flex047/user_avatar/forum.generic-mapping-tools.org/pwessel/32/30_2.png) [@pwessel](https://forum.generic-mapping-tools.org/u/pwessel)\ **Post date:** [August 12, 2021, 2:09am UTC](https://forum.generic-mapping-tools.org/t/sample1d-dont-eliminate-duplicate-values/1976/2 "2021-08-12T02:09:44Z")
Hm, yes I agree there really should not be any reason to ban duplicate points given via -T. Once the spline is defined by lookup.xy then you should be able to sample at any value and repeatedly. So not quite what the other thread was all about but I will need to check things as I do not want to break something we have fixed. I will have a look. ---
**Author:** ![mjh217](https://avatars.discourse-cdn.com/v4/letter/m/bc8723/32.png) [@mjh217](https://forum.generic-mapping-tools.org/u/mjh217)\ **Post date:** [April 7, 2022, 3:14am UTC](https://forum.generic-mapping-tools.org/t/sample1d-dont-eliminate-duplicate-values/1976/3 "2022-04-07T03:14:56Z")
Hi Paul, I was just wondering if this got fixed at some point? Or whether anyone came up with a workaround? I tried it in 6.3.0 with the same result. Cheers! ---
**Author:** ![pwessel](https://yyz1.discourse-cdn.com/flex047/user_avatar/forum.generic-mapping-tools.org/pwessel/32/30_2.png) [@pwessel](https://forum.generic-mapping-tools.org/u/pwessel)\ **Post date:** [April 7, 2022, 9:00am UTC](https://forum.generic-mapping-tools.org/t/sample1d-dont-eliminate-duplicate-values/1976/4 "2022-04-07T09:00:17Z")
Works fine in master so either build from github or wait for 6.4 (\< 1 month): ``` gmt sample1d -Fl -Tlookup.xy sample.x 0.5 5 1.5 15 1.9 19 1.5 15 ``` ---
**Author:** ![mjh217](https://avatars.discourse-cdn.com/v4/letter/m/bc8723/32.png) [@mjh217](https://forum.generic-mapping-tools.org/u/mjh217)\ **Post date:** [April 7, 2022, 9:46pm UTC](https://forum.generic-mapping-tools.org/t/sample1d-dont-eliminate-duplicate-values/1976/5 "2022-04-07T21:46:41Z")
Thanks a lot! Much appreciated