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<DIV><FONT color=#000000>Thanks Saber, Micha and Carlos for your
responses,</FONT></DIV>
<DIV><FONT color=#000000></FONT> </DIV>
<DIV><FONT color=#000000>I tried the <FONT
style="FONT-SIZE: 11pt">v.to.rast.attribute route (and also v.rast.value), but
couldn’t get those tool to work with my data set (and I’m still exploring this
issue and trying to work out what’s going on as they look like useful tools to
be able to use).</FONT></FONT></DIV>
<DIV><FONT style="FONT-SIZE: 11pt" color=#000000></FONT> </DIV>
<DIV><FONT style="FONT-SIZE: 11pt"><FONT color=#000000>However, returning to the
original Rasterize tool, I examined the raster data layer which was created in
more detail and found that while the histogram was saying that the maximum value
was <FONT style="FONT-SIZE: 12pt">0.995968, when I interrogated the individual
grid cells with the Interrogate Features tool, the values were indeed one where
they should be. Thus, my problem was not that the Rasterize tool was not
working, but rather that it wasn’t being displayed correctly in QGIS.
</FONT></FONT></FONT></DIV>
<DIV><FONT style="FONT-SIZE: 11pt"><FONT style="FONT-SIZE: 12pt"
color=#000000></FONT></FONT> </DIV>
<DIV><FONT style="FONT-SIZE: 11pt"><FONT color=#000000><FONT
style="FONT-SIZE: 12pt">To deal with this, I went into the Layer Properties and
under the Style tab, I changed the maximum value from 0.995968 to 1</FONT>. This
made the legend in the Table Of Contents window look a little odd, but the layer
displayed correctly, has the right value in it, and does the correct
calculations when using the raster calculator tool. </FONT></FONT></DIV>
<DIV><FONT color=#000000></FONT> </DIV>
<DIV><FONT color=#000000>I’m not too sure why the layer is not being displayed
correctly in the Table Of Contents window in the first place. Similarly, if I
remove the raster data layer from the my project and add it back in again, it
reverts to saying the maximum value is 0.995968 rather than 1 in the legend in
the Table Of Contents window and in the histogram for the data layer. Thus, each
time I use it in a new project, I have to manually change the maximum number to
1. </FONT></DIV>
<DIV><FONT color=#000000></FONT> </DIV>
<DIV><FONT color=#000000>I don’t know if this is a bug as such, or if this
happens with other data sets (it happened with both of mine – one point and one
line data layer), but it is certainly a potential pitfall for the novice user
when it occurs.</FONT></DIV>
<DIV> </DIV>
<DIV><FONT color=#000000>All the best,</FONT></DIV>
<DIV><FONT color=#000000></FONT> </DIV>
<DIV><FONT color=#000000>Colin</FONT></DIV>
<DIV> </DIV>
<DIV
style="FONT-FAMILY: 'Calibri'; COLOR: #000000; FONT-SIZE: 12pt">==================================================================================<BR>GIS
IN ECOLOGY - Providing Training, Advice And Consultancy On The Use Of GIS In
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<BR>An Introduction To Using GIS In Marine Biology: Supplementary Workbook Two -
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<DIV> </DIV>
<DIV style="BACKGROUND: #f5f5f5">
<DIV style="font-color: black"><B>From:</B> <A title=sig.upagu@gmail.com
href="mailto:sig.upagu@gmail.com">Carlos Cerdán</A> </DIV>
<DIV><B>Sent:</B> Thursday, April 10, 2014 9:23 PM</DIV>
<DIV><B>To:</B> <A title=qgis-user@lists.osgeo.org
href="mailto:qgis-user@lists.osgeo.org">qgis-user@lists.osgeo.org</A> </DIV>
<DIV><B>Subject:</B> Re: [Qgis-user] Problem with Rasterize (Vector to raster)
tool</DIV></DIV></DIV>
<DIV> </DIV></DIV>
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<DIV dir=ltr>
<DIV>
<DIV>Perhaps raster calculator can also help
you<BR><BR>Expression:<BR><BR>(layer>0 and layer <= 1)<BR><BR>Gives us 1
when sentence is true and 0 for false, for each cell in
"layer".<BR><BR></DIV>Good luck<BR><BR></DIV>Carlos<BR>
<DIV>
<DIV><BR><BR></DIV></DIV></DIV>
<DIV class=gmail_extra><BR><BR>
<DIV class=gmail_quote>2014-04-10 9:29 GMT-05:00 Micha Silver <SPAN
dir=ltr><<A href="mailto:micha@arava.co.il"
target=_blank>micha@arava.co.il</A>></SPAN>:<BR>
<BLOCKQUOTE
style="BORDER-LEFT: #ccc 1px solid; MARGIN: 0px 0px 0px 0.8ex; PADDING-LEFT: 1ex"
class=gmail_quote>
<DIV style="DIRECTION: ltr" text="#000000" bgcolor="#FFFFFF">
<DIV>Using GRASS there are two modules you can consider. First :<BR>v.to.rast
in=... out=... type=point use=val value=1<BR>will convert points into raster
cells (at the current region settings), where any cell that contains at least
one point will be given value 1.<BR><BR>Next:<BR>r.in.xyz in=... out=...
method=sum <BR>will create a raster (at the current region settings) where
each cell will have a value = the count of points in that
cell.<BR><BR>HTH,<BR>Micha
<DIV>
<DIV class=h5><BR>On 04/10/2014 04:20 PM, Colin D. MacLeod
wrote:<BR></DIV></DIV></DIV>
<BLOCKQUOTE type="cite">
<DIV>
<DIV class=h5>
<DIV dir=ltr>
<DIV style="FONT-FAMILY: 'Calibri'; FONT-SIZE: 12pt">
<DIV>Hi All,</DIV>
<DIV> </DIV>
<DIV>I’m a fairly experienced GIS user, but I’m new to QGIS. I’m using
version 2.2, and I’m trying to convert a point data layer into a raster data
layer using the Rasterize tool. The point data layer has an integer field
with a value of 1 for all records, and I want to make a raster data layer
which has a value of one for each cell which has at least one point in it
(some cells have more than one point in them). When I use the Rasterize
tool, it creates the raster data layer fine, but all cells with have points
in them appear to have a value of 0.995968. I’ve tried editing the gdal code
(even making the resulting raster data layer an integer layer), but I still
cannot get it to produce a raster with a value of 1 rather than just a
number very close to one. </DIV>
<DIV> </DIV>
<DIV>Does anyone have any suggestions of where I might be going wrong and/or
how to solve this issue?</DIV>
<DIV> </DIV>
<DIV>On a related note, is it possible to use the Rasterize tool to work out
the average or total values for all the points which fall in each grid cell?
If so, how (I can’t find anything in the gdal instructions themselves which
would suggest this is possible, but I might be missing something). If this
isn’t possible to do with the Rasterize tool, are there other tools in QGIS
which can do this?</DIV>
<DIV> </DIV>
<DIV>Thanks for any help anyone can give on this.</DIV>
<DIV> </DIV>
<DIV>All the best,</DIV>
<DIV> </DIV>
<DIV>Colin</DIV>
<DIV> </DIV>
<DIV
style="FONT-FAMILY: 'Calibri'; FONT-SIZE: 12pt">==================================================================================<BR>GIS
IN ECOLOGY - Providing Training, Advice And Consultancy On The Use Of GIS In
Ecology<BR><BR>Web: <A href="http://www.GISinEcology.com"
target=_blank>www.GISinEcology.com</A> Email: <A
href="mailto:info@GISinEcology.com"
target=_blank>info@GISinEcology.com</A><BR><BR>Need to ask a question about
using GIS? Try the GIS In Ecology Forum: <A
href="http://www.GISinEcology.com/GIS_in_Ecology_forum.htm"
target=_blank>www.GISinEcology.com/GIS_in_Ecology_forum.htm</A><BR><BR>Books
From GIS In Ecology Staff:<BR><BR>An Introduction To Using GIS In Marine
Biology; RRP: £44.99<BR>An Introduction To Using GIS In Marine Biology:
Supplementary Workbook One - Creating Maps Of Species Distribution; RRP:
£19:99 <BR>An Introduction To Using GIS In Marine Biology: Supplementary
Workbook Two - Working With Raster Data Layers; RRP: £19.99 <BR><BR>If you
wish to purchase these books, visit: <A
href="http://www.gisinecology.com/Book_Shop.htm"
target=_blank>http://www.gisinecology.com/Book_Shop.htm</A><BR><BR>To help
the environment, please do not print out this email unless it is
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