Invalid points in grid -problem with data items

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lilianseiler@yahoo.com.br
MOHID User
Posts: 24
Joined: Thu Jan 01, 1970 00:00

Invalid points in grid -problem with data items

Postby lilianseiler@yahoo.com.br » Fri Aug 28, 2009 19:48

Hi

I´m beginer user of MOHID GIS and i have some problems to make my grid. Data items are:

- \".Xyz\" , with structure:

<begin_xyz>
397308.57 6444322.4 0.1
397802.2 6443689.7 0.1
.
.
767239.32 6825202.6 100
776371.7 6854927.4 100
<end_xyz>



-\".xy\". with structure:
<beginpolygon>
28799.095 6122068.4 0
34388.511 6126820.2 0
40978.432 6129302.4 0
.
.
159431.4 6135870.4 0
28799.095 6122068.4 0
<endpolygon>


- \".grd\", created in MOHID GIS


Obs.: All points of bathymetry are positive



First probleman is: the data items of \".xyz\" have some points out of the points to correct bathymetry and \".xy\" some points out of the polygon,
how can i take off then?



SEcond, After imported thats data itens, i used the tool´´ Create Digital Terrain'' , that created data item \".dat\". The problem is that: why when i visualize this archive, all points of grid are with
value -99? Like this:
.
.
4900.000
5000.000
<EndYY>
<BeginGridData2D>
-999.0000
-999.0000
.
.
-999.0000
-999.0000
<EndGridData2D>


I hope answers, please


Thanks so much

Lilian :oops:

luis_at_mohid.com
MOHID Developer
Posts: 553
Joined: Thu Jan 01, 1970 00:00
Location: Instituto Superior Técnico - Technical University of Lisbon
Contact:

Postby luis_at_mohid.com » Mon Sep 21, 2009 17:31

Hi Lilian,

I could not understand the first problem. If there are XYZ and XY points outside the grid area there is no problem and you don't need to take the points out.

Second problem: I am not sure what's happening. I would have to see the files and options you are using.

Best regards,
Luis

rafael_fergo@hotmail.com
MOHID Beginner
Posts: 6
Joined: Thu Jan 01, 1970 00:00

MAYBE

Postby rafael_fergo@hotmail.com » Wed Nov 17, 2010 15:22

The first problem is maybe happening becouse your coordinates ! you collected your bathymetry points those values were in UTM or GEOGRAPHICAL ? try to fix this !buts not sure.

Second problem , maybe this values -999 are conected to land areas .. those areas that do not fill the inside polygon.

just some ideias hope it helps


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