# Grdtrack -Z overrides -s?

**URL:** <https://forum.generic-mapping-tools.org/t/grdtrack-z-overrides-s/1745>\
**Category:** Q&A\
**Created:** [June 1, 2021, 2:06am UTC](https://forum.generic-mapping-tools.org/t/grdtrack-z-overrides-s/1745 "2021-06-01T02:06:36Z")\
**Posts on this page:** 3\
**Page:** 1

<div class="post-metadata">

**Author:** ![thwbecker](https://yyz1.discourse-cdn.com/flex047/user_avatar/forum.generic-mapping-tools.org/thwbecker/32/1215_2.png) [@thwbecker](https://forum.generic-mapping-tools.org/u/thwbecker)\
**Post date:** [June 1, 2021, 2:06am UTC](https://forum.generic-mapping-tools.org/t/grdtrack-z-overrides-s/1745/1 "2021-06-01T02:06:36Z")

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It appears that github GMT grdtrack has the -Z (only value output) override the -s option (suppress NaN). I would expect this

```
#!/bin/bash
grdmath -R0/1/0/1 -I0.1 Y 0.5 GE 1 NAN = tmp.grd
for opt in "-s" "-s -Z";do
    echo $0: option $opt
    echo 0.5 0.75 | grdtrack -Gtmp.grd $opt
    echo 0.5 0.25 | grdtrack -Gtmp.grd $opt
done

```

to out only the y = 0.25 entry (grid is meant to be NaN for y \> 0.5, zero else), but I get

```
> ./test_grdtrack
./test_grdtrack: option -s
0.5	0.25	0
./test_grdtrack: option -s -Z
NaN
0
```

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<div class="post-metadata">

**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:** [June 1, 2021, 4:39pm UTC](https://forum.generic-mapping-tools.org/t/grdtrack-z-overrides-s/1745/2 "2021-06-01T16:39:00Z")

</div>

Thanks Thorsten, has now been fixed in [master](https://github.com/GenericMappingTools/gmt/pull/5286). Please give it a spin and let us know if anything else shows up.

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<div class="post-metadata">

**Author:** ![thwbecker](https://yyz1.discourse-cdn.com/flex047/user_avatar/forum.generic-mapping-tools.org/thwbecker/32/1215_2.png) [@thwbecker](https://forum.generic-mapping-tools.org/u/thwbecker)\
**Post date:** [June 1, 2021, 5:05pm UTC](https://forum.generic-mapping-tools.org/t/grdtrack-z-overrides-s/1745/3 "2021-06-01T17:05:47Z")

</div>

Thanks! Works now for my test cases.