<html xmlns:v="urn:schemas-microsoft-com:vml" xmlns:o="urn:schemas-microsoft-com:office:office" xmlns:w="urn:schemas-microsoft-com:office:word" xmlns:m="http://schemas.microsoft.com/office/2004/12/omml" xmlns="http://www.w3.org/TR/REC-html40"><head><meta http-equiv=Content-Type content="text/html; charset=utf-8"><meta name=Generator content="Microsoft Word 15 (filtered medium)"><style><!--
/* Font Definitions */
@font-face
{font-family:"Cambria Math";
panose-1:2 4 5 3 5 4 6 3 2 4;}
@font-face
{font-family:Calibri;
panose-1:2 15 5 2 2 2 4 3 2 4;}
/* Style Definitions */
p.MsoNormal, li.MsoNormal, div.MsoNormal
{margin:0in;
margin-bottom:.0001pt;
font-size:12.0pt;
font-family:"Times New Roman",serif;}
a:link, span.MsoHyperlink
{mso-style-priority:99;
color:#0563C1;
text-decoration:underline;}
a:visited, span.MsoHyperlinkFollowed
{mso-style-priority:99;
color:#954F72;
text-decoration:underline;}
span.gmail-m2033918191318644142cye-lm-tag
{mso-style-name:gmail-m_2033918191318644142cye-lm-tag;}
span.cye-lm-tag
{mso-style-name:cye-lm-tag;}
span.EmailStyle19
{mso-style-type:personal-reply;
font-family:"Calibri",sans-serif;
color:#1F497D;}
.MsoChpDefault
{mso-style-type:export-only;
font-family:"Calibri",sans-serif;}
@page WordSection1
{size:8.5in 11.0in;
margin:1.0in 1.0in 1.0in 1.0in;}
div.WordSection1
{page:WordSection1;}
--></style><!--[if gte mso 9]><xml>
<o:shapedefaults v:ext="edit" spidmax="1026" />
</xml><![endif]--><!--[if gte mso 9]><xml>
<o:shapelayout v:ext="edit">
<o:idmap v:ext="edit" data="1" />
</o:shapelayout></xml><![endif]--></head><body lang=EN-US link="#0563C1" vlink="#954F72"><div class=WordSection1><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D'>It doesn't grab adjacent tiles. To consider adjacent tiles you'd need to use ST_Union to stitch together multiple tiles.<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D'><o:p> </o:p></span></p><div style='border:none;border-left:solid blue 1.5pt;padding:0in 0in 0in 4.0pt'><div><div style='border:none;border-top:solid #E1E1E1 1.0pt;padding:3.0pt 0in 0in 0in'><p class=MsoNormal><b><span style='font-size:11.0pt;font-family:"Calibri",sans-serif'>From:</span></b><span style='font-size:11.0pt;font-family:"Calibri",sans-serif'> postgis-users [mailto:postgis-users-bounces@lists.osgeo.org] <b>On Behalf Of </b>David Haynes<br><b>Sent:</b> Wednesday, June 13, 2018 12:56 PM<br><b>To:</b> postgis-users@lists.osgeo.org<br><b>Subject:</b> [postgis-users] raster operations<o:p></o:p></span></p></div></div><p class=MsoNormal><o:p> </o:p></p><div><div><p class=MsoNormal><span class=gmail-m2033918191318644142cye-lm-tag><span style='font-size:9.5pt'>I have a question about how to focal operations for raster statistics are working. I started off comparing the old depreciated function st_mapalgebrafctngb with the current version st_mapalgebra. The difference I have determined is that the st_mapalgebrafctngb will pass the call back function to the raster dataset similar to the st_mapalgebra, but as the function approaches the edge of the raster tile things get wonky. What are values that are assigned to pixels that do not have sufficient neighbors? When I run this bit of code. The ST_Value function reports that no values have been assigned. I assume this can be remedied by adding information through userargs.</span></span><span style='font-size:9.5pt'><o:p></o:p></span></p></div><div><p class=MsoNormal><span style='font-size:9.5pt'><o:p> </o:p></span></p></div><div><p class=MsoNormal><span class=gmail-m2033918191318644142cye-lm-tag><span style='font-size:9.5pt'>with smoothed_raster as</span></span><span style='font-size:9.5pt'><o:p></o:p></span></p></div><div><p class=MsoNormal><span class=gmail-m2033918191318644142cye-lm-tag><span style='font-size:9.5pt'>(</span></span><span style='font-size:9.5pt'><o:p></o:p></span></p></div><div><p class=MsoNormal><span class=gmail-m2033918191318644142cye-lm-tag><span style='font-size:9.5pt'>SELECT st_mapalgebrafctngb(rast, 1, NULL, 1, 1, 'st_mean4ma(double precision[][][],text,text[])'::regprocedure, 'ignore', NULL) as rast</span></span><span style='font-size:9.5pt'><o:p></o:p></span></p></div><div><p class=MsoNormal><span class=gmail-m2033918191318644142cye-lm-tag><span style='font-size:9.5pt'>FROM glc2000_clipped_250 r</span></span><span style='font-size:9.5pt'><o:p></o:p></span></p></div><div><p class=MsoNormal><span class=gmail-m2033918191318644142cye-lm-tag><span style='font-size:9.5pt'>WHERE r.rid = 25</span></span><span style='font-size:9.5pt'><o:p></o:p></span></p></div><div><p class=MsoNormal><span class=gmail-m2033918191318644142cye-lm-tag><span style='font-size:9.5pt'>), original_raster as</span></span><span style='font-size:9.5pt'><o:p></o:p></span></p></div><div><p class=MsoNormal><span class=gmail-m2033918191318644142cye-lm-tag><span style='font-size:9.5pt'>(</span></span><span style='font-size:9.5pt'><o:p></o:p></span></p></div><div><p class=MsoNormal><span class=gmail-m2033918191318644142cye-lm-tag><span style='font-size:9.5pt'>SELECT r.rast</span></span><span style='font-size:9.5pt'><o:p></o:p></span></p></div><div><p class=MsoNormal><span class=gmail-m2033918191318644142cye-lm-tag><span style='font-size:9.5pt'>FROM glc2000_clipped_250 r</span></span><span style='font-size:9.5pt'><o:p></o:p></span></p></div><div><p class=MsoNormal><span class=gmail-m2033918191318644142cye-lm-tag><span style='font-size:9.5pt'>WHERE r.rid = 25</span></span><span style='font-size:9.5pt'><o:p></o:p></span></p></div><div><p class=MsoNormal><span class=gmail-m2033918191318644142cye-lm-tag><span style='font-size:9.5pt'>)</span></span><span style='font-size:9.5pt'><o:p></o:p></span></p></div><div><p class=MsoNormal><span class=gmail-m2033918191318644142cye-lm-tag><span style='font-size:9.5pt'>SELECT x, y, ST_Value(s.rast, x,y) as smoothed, ST_Value(o.rast, x,y) as original</span></span><span style='font-size:9.5pt'><o:p></o:p></span></p></div><div><p class=MsoNormal><span class=gmail-m2033918191318644142cye-lm-tag><span style='font-size:9.5pt'>FROM smoothed_raster s, original_raster o</span></span><span style='font-size:9.5pt'><o:p></o:p></span></p></div><div><p class=MsoNormal><span class=gmail-m2033918191318644142cye-lm-tag><span style='font-size:9.5pt'>CROSS JOIN generate_series(1,10) as x</span></span><span style='font-size:9.5pt'><o:p></o:p></span></p></div><div><p class=MsoNormal><span class=gmail-m2033918191318644142cye-lm-tag><span style='font-size:9.5pt'>CROSS JOIN generate_series(1,10) as y</span></span><span style='font-size:9.5pt'><o:p></o:p></span></p></div><div><p class=MsoNormal><span class=gmail-m2033918191318644142cye-lm-tag><span style='font-size:9.5pt'> </span></span><span style='font-size:9.5pt'><o:p></o:p></span></p></div><div><p class=MsoNormal><span class=gmail-m2033918191318644142cye-lm-tag><span style='font-size:9.5pt'>This leads me to a larger question regarding</span></span><span class=cye-lm-tag><span style='font-size:9.5pt'> </span></span><span class=gmail-m2033918191318644142cye-lm-tag><span style='font-size:9.5pt'>focal analysis functions for raster datasets. Do these functions cross the tiles? Assume you have 9 tiles and each tile is composed of 3x3 pixels. Tiles 1-3 in row 1, 4-6 row 2 etc. If you have a neighborhood analysis function performing on tile 5. Will it grab adjacent pixels in tile 6? Unfortunately the examples I created returned with the same result.</span></span><span style='font-size:9.5pt'><o:p></o:p></span></p></div><p class=MsoNormal><o:p> </o:p></p></div></div></div></body></html>