[GRASS-user] i.PCA r.info output format

GRASS GRASS user
1

Rebecca wrote:

I have undertaken a number of transformations of spectral
data using the i.pca in both GRASS 6.4 and GRASS 7.
Unfortunately when more than 6 bands are used r.info cannot
display the eigen vectors and % importance
Output for r.info should look like this:

  PC1 1170.12 ( -0.63 -0.65 -0.43 ) [ 88.07% ]
PC2 152.49 ( 0.23 0.37 -0.90 ) [ 11.48% ]

But instead looks like this:

PC1 13770134.87 ( 0.1019, 0.5087, 0.1896, 0.5185, 0.4578, 0.4527, 0.107
6PC2 174134.96 ( 0.6530,-0.1228,-0.0673,-0.1493,-0.0026, 0.0203, 0.7289

with the full metadata being truncated.

As I know the values are being calculated as they display
in the i.pca output upon completion, so this appears to be a
size issue with the display of r.info?

GRASS 6's metadata system has a historical wart which limits
the history file's column width to 80 characters and 40 lines.

Is there any way to access the full metadata for the rasters
without recalculating them?

If you're lucky, the data will be in the $MAPSET/hist/$MAPNAME
file and r.info is just failing to pass it on.

If it's not, please let us know/file a bug report.

Hamish

2

Thanks Hamish. I am not lucky this time, the information in this file is also truncated. :frowning:
I have tried to create a bug report but failed as I am not a recognised user?
Cheers,
Rebecca

From: Hamish hamish_b@yahoo.com
To: GRASS user list grass-user@lists.osgeo.org; Rebecca Bennett rabennett@ymail.com
Sent: Thu, 10 February, 2011 22:31:08
Subject: Re: [GRASS-user] i.PCA r.info output format

Rebecca wrote:

I have undertaken a number of transformations of spectral
data using the i.pca in both GRASS 6.4 and GRASS 7.
Unfortunately when more than 6 bands are used r.info cannot
display the eigen vectors and % importance
Output for r.info should look like this:

PC1 1170.12 ( -0.63 -0.65 -0.43 ) [ 88.07% ]
PC2 152.49 ( 0.23 0.37 -0.90 ) [ 11.48% ]

But instead looks like this:

PC1 13770134.87 ( 0.1019, 0.5087, 0.1896, 0.5185, 0.4578, 0.4527, 0.107
6PC2 174134.96 ( 0.6530,-0.1228,-0.0673,-0.1493,-0.0026, 0.0203, 0.7289

with the full metadata being truncated.

As I know the values are being calculated as they display
in the i.pca output upon completion, so this appears to be a
size issue with the display of r.info?

GRASS 6’s metadata system has a historical wart which limits
the history file’s column width to 80 characters and 40 lines.

Is there any way to access the full metadata for the rasters
without recalculating them?

If you’re lucky, the data will be in the $MAPSET/hist/$MAPNAME
file and r.info is just failing to pass it on.

If it’s not, please let us know/file a bug report.

Hamish