<br><br><div class="gmail_quote">2010/1/21 Hamish <span dir="ltr">&lt;<a href="mailto:hamish_b@yahoo.com">hamish_b@yahoo.com</a>&gt;</span><br><blockquote class="gmail_quote" style="border-left: 1px solid rgb(204, 204, 204); margin: 0pt 0pt 0pt 0.8ex; padding-left: 1ex;">
<div><div></div><div class="h5">maven apache wrote:<br>
&gt; I have a geotiff now, and some cells have a not-expected<br>
&gt; value, so I want to Interpolation them, and I notice that<br>
&gt; there is a command named r.fillnull, however the cell to be<br>
&gt; changed is not null, so I want to :<br>
&gt; 1) change the special  cell value to null<br>
&gt;<br>
&gt; 2) use the r.fillnull to Interpolation.<br>
&gt;<br>
&gt; The problem is I do not know how to do the step 1 with<br>
&gt; grass, anyone can do me a favor?<br>
<br>
<br>
</div></div>try r.null.<br>
<font color="#888888"><br>
<br>
Hamish<br>
<br>
<br>
<br></font></blockquote><div>Hi;<br>It seems that the r.null does not work.<br><br>1) I use the <a href="http://r.info">r.info</a> to get the info of the tiff which I have imported to grass and I got that:<br>Hi:<br>
<br>
(Thu Jan 21 09:56:46 2010)                                                      <br>
<a href="http://r.info">r.info</a> map=aaa@PERMANENT                                                        <br>
 +----------------------------------------------------------------------------+<br>
 | Layer:    aaa@PERMANENT                  Date: Tue Jan 12 16:02:39 2010    |<br>
 | Mapset:   PERMANENT                      Login of Creator: Administrator   |<br>
 | Location: hdf5loc                                                          |<br>
 | DataBase: D:\GrassDataBase                                                 |<br>
 | Title:     ( aaa )                                                         |<br>
 | Timestamp: none                                                            |<br>
 |----------------------------------------------------------------------------|<br>
 |                                                                            |<br>
 |   Type of Map:  raster               Number of Categories: 499             |<br>
 |   Data Type:    FCELL                                                      |<br>
 |   Rows:         720                                                        |<br>
 |   Columns:      1440                                                       |<br>
 |   Total Cells:  1036800                                                    |<br>
 |        Projection: Latitude-Longitude                                      |<br>
 |            N:        90N    S:        90S   Res:  0:15                     |<br>
 |            E:       180E    W:       180W   Res:  0:15                     |<br>
 |   Range of data:    min = -1267650600228229401496703205376.000000  max = 4 |<br>
 |                                                                            |<br>
 |   Data Description:                                                        |<br>
 |    generated by r.in.gdal                                                  |<br>
 |                                                                            |<br>
 |   Comments:                                                                |<br>
 |    r.in.gdal input=&quot;D:\data\hdf5\aaa.tif&quot; output=&quot;aaa&quot;                     |<br>
 |                                                                            |<br>
 +----------------------------------------------------------------------------+<br>
(Thu Jan 21 09:56:47 2010) Command finished (0 sec)                             <br>
(Thu Jan 21 09:56:50 2010)    <br>
<br><br>2)then I use r.null to set the null value to null:  
r.null setnull=-1.26765060022823e+030<br>
<br>
<br>3) I use the <a href="http://r.info">r.info</a> again to see if it is changed :<br>
<a href="http://r.info">r.info</a> -r map=aaa@PERMANENT                                                     <br>
min=-1.26765060022823e+030<br>
max=498.5<br>
(Thu Jan 21 09:56:50 2010) Command finished (0 sec)                             <br> </div></div>It seems that the valuse are  not changed to null.<br><br>I wonder why?<br>