Opened 12 years ago

Closed 11 years ago

#105 closed enhancement (fixed)

r.in.xyz: zscale parameter addition patch

Reported by: neteler Owned by: hamish
Priority: major Milestone: 6.4.0
Component: Default Version: svn-trunk
Keywords: r.in.xyz Cc: grass-dev@…
CPU: Unspecified Platform: Unspecified

Description

Hi,

I have implemented a zscale parameter in r.in.xyz. Patch submitted to trac for review.

Markus

Attachments (1)

diff (3.3 KB) - added by neteler 12 years ago.
r.in.xyz new zscale param

Download all attachments as: .zip

Change History (8)

Changed 12 years ago by neteler

Attachment: diff added

r.in.xyz new zscale param

comment:1 Changed 12 years ago by hamish

Cc: grass-dev@… added
Owner: changed from grass-dev@… to hamish
Status: newassigned

Hi,

Sorry I missed the earlier discussion of the -i flag [for ignoring malformed lines in the data stream]; I had been out of town.

In general my plan for r.in.xyz was to keep the interface (and code) as simple as possible. The idea is to keep the methodology clean + light, and so the code bug free + fast.

The code for the -i flag won't slow down the module any (vs prior) and doesn't really add program complexity, so I don't have a technical problem with it. Still, for reducing methodology mistakes & encouraging a hands-on approach to data management, I consider it preferable that the user should be forced to do something to fix their broken input files rather than hack their way around them without careful study of what the problem really is. If there are many files to process they could filter the stream through any number of UNIX tools like sed or awk and then pipe the result to r.in.xyz's stdin in some automated way.

--

A zscale= option seems like a reasonable request. Is the purpose that the elevation data comes in feet and you want it in meters?

I will review the patch, run some speed tests, and take care of committing as soon as time allows.

Hamish

comment:2 Changed 12 years ago by neteler

I would appreciate if you don't revert the -i flag. It's a major PITA to manually fix files as in the indicated case (with Lidar, you often have hundreds of tiles to process).

The purpose that the elevation data comes in feet and you want it in meters or you want centimeters or whatever. Data often come in a different way than desired.

Markus

comment:3 Changed 12 years ago by hamish

Don't worry, I don't mean to revert the -i flag, but I did want to make clear my design philosophy. If the input file is that badly broken then a million WARNINGs should be disincentive enough to discourage lazy abuse of the flag.

FWIW, to chop off the last row of a file, use head with a negative index:

head -n -1 filename.txt | r.in.xyz in=- out=foo ...

Hamish

comment:4 Changed 11 years ago by hamish

Keywords: r.in.xyz added

Patch committed by Markus; looks good. Closing wish.

Hamish

comment:5 Changed 11 years ago by hamish

Resolution: fixed
Status: assignedclosed

comment:6 Changed 11 years ago by hamish

Resolution: fixed
Status: closedreopened
z=z/zscale;

shouldn't that be z *= zscale; ??

Hamish

comment:7 Changed 11 years ago by hamish

Resolution: fixed
Status: reopenedclosed

With r31713 r.in.xyz's zscale has been changed in svn to multiply by the scale factor, not divide.

reclosing ticket.

Hamish

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