new *.laz but old *.lax

[TLVermGeo Ciesilski, Stefan]

Hello Martin,

 

I have some *.laz file exchanged, but forgotten to create the *.lax file new.

When running lasclip, the process runs. But he is not finished and show no errors.

lasinfo does not show any errors of the lax file.

It is possible to check the *.lax separately.

 

 

Thank you very much

Stefan

[Martin Isenburg]

Hello,

when exchanging LAZ files but leaving the LAX files in place there is indeed the potential that bad things happen. For example, if you were to use las2las to drop all points with class 7 (noise) and then store the LAZ file back to the exact same file name without generating a new LAZ file, then things could go haywire. However, checking a LAX file for correctness requires - to be absolutely sure - almost as much time as generating an entirely new LAX file so the easiest would be to re-run

lasindex -i *.laz -cores 7

at the end of making modifications. However ... it seems you are not the only one who has run into this issue so maybe we'll make appending the LAX file the common practice and give the user the option to auto-generate it on-the-fly during each write when both '-olaz' and '-olax' is specified.

Martin

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[Perdue, Michael]

+1 vote from this user!

 

“make appending the LAX file the common practice and give the user the option to auto-generate it on-the-fly during each write when both '-olaz' and '-olax' is specified.”

 

[TLVermGeo Ciesilski, Stefan]

Hello Martin,
Yes exactly I have the lax with lasindex re-generated and everything worked
lasindex -i * .laz

It would be better if a error would come, that something with the lax is not true if there are problems. Since I needed something until I found why it does not work.

The on the fly creation with '-olax' is a good idea. Can lax standard always be generated with and there is an parameter to turn this off? So the reverse way

 

Thank you very much

--

[Terje Mathisen]

TLVermGeo Ciesilski, Stefan wrote:
>
> Hello Martin,
> Yes exactly I have the lax with lasindex re-generated and everything
> worked
> lasindex -i * .laz
>
> It would be better if a error would come, that something with the lax
> is not true if there are problems. Since I needed something until I
> found why it does not work.
>

The obvious approach is a simple 'make' style test, i.e.

"The LAX file has to be newer (or equal?) than the LAZ file".

For this to work you (Martin) have to close the LAX file after the LAZ
file if you generate both at the same time, but the rest should be trivial.

You probably still need the ability to force an update but the default
could be to check timestamps.

Terje

>
>
> The on the fly creation with '-olax' is a good idea. Can lax standard
> always be generated with and there is an parameter to turn this off?
> So the reverse way
>
> Thank you very much
>

> *Von:*last...@googlegroups.com [mailto:last...@googlegroups.com] *Im
> Auftrag von *Perdue, Michael
> *Gesendet:* Dienstag, 8. August 2017 17:44
> *An:* last...@googlegroups.com
> *Betreff:* RE: [LAStools] new *.laz but old *.lax

>
> +1 vote from this user!
>
> “make appending the LAX file the common practice and give the user the
> option to auto-generate it on-the-fly during each write when both
> '-olaz' and '-olax' is specified.”
>
> --
> Download LAStools at
> http://lastools.org
> http://rapidlasso.com
> Be social with LAStools at
> http://facebook.com/LAStools
> http://twitter.com/LAStools
> http://linkedin.com/groups/LAStools-4408378
> Manage your settings at
> http://groups.google.com/group/lastools/subscribe
>
> --
> Download LAStools at
> http://lastools.org
> http://rapidlasso.com
> Be social with LAStools at
> http://facebook.com/LAStools
> http://twitter.com/LAStools
> http://linkedin.com/groups/LAStools-4408378
> Manage your settings at
> http://groups.google.com/group/lastools/subscribe

--
- <Terje.M...@tmsw.no>
"almost all programming can be viewed as an exercise in caching"