<div dir="ltr">Hi,<div><br></div><div>I'm glad you opened that topic. If you change region in C or using ctypes in Python, it is affecting only the current process. While g.region reads/writes the file with region but obviously will not change your process region in Python (when using ctypes). And then there are the temporary regions. To design an API for it is a challenge. I think I even wrote something about it to documentation but it needs to be completely rewritten to be actually readable.<br>
</div><div><br></div><div>Vaclav</div></div><div class="gmail_extra"><br><br><div class="gmail_quote">On Thu, Feb 27, 2014 at 5:02 PM, Pietro <span dir="ltr"><<a href="mailto:peter.zamb@gmail.com" target="_blank">peter.zamb@gmail.com</a>></span> wrote:<br>
<blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><div dir="ltr"><div class="gmail_quote"><div dir="ltr"><div><p style="margin:1.2em 0px!important">Dear devs,</p><p style="margin:1.2em 0px!important">
I got different results if I use <code style="font-size:0.85em;font-family:Consolas,Inconsolata,Courier,monospace;margin:0px 0.15em;padding:0px 0.3em;white-space:pre-wrap;border:1px solid rgb(234,234,234);background-color:rgb(248,248,248);border-top-left-radius:3px;border-top-right-radius:3px;border-bottom-right-radius:3px;border-bottom-left-radius:3px;display:inline">ctypes</code> or the module <code style="font-size:0.85em;font-family:Consolas,Inconsolata,Courier,monospace;margin:0px 0.15em;padding:0px 0.3em;white-space:pre-wrap;border:1px solid rgb(234,234,234);background-color:rgb(248,248,248);border-top-left-radius:3px;border-top-right-radius:3px;border-bottom-right-radius:3px;border-bottom-left-radius:3px;display:inline">g.region</code>, I wrote:</p>
<pre style="font-size:0.85em;font-family:Consolas,Inconsolata,Courier,monospace;font-size:1em;line-height:1.2em;margin:1.2em 0px"><code style="font-size:0.85em;font-family:Consolas,Inconsolata,Courier,monospace;margin:0px 0.15em;padding:0px 0.3em;white-space:pre-wrap;border:1px solid rgb(234,234,234);background-color:rgb(248,248,248);border-top-left-radius:3px;border-top-right-radius:3px;border-bottom-right-radius:3px;border-bottom-left-radius:3px;display:inline;white-space:pre-wrap;overflow:auto;border-top-left-radius:3px;border-top-right-radius:3px;border-bottom-right-radius:3px;border-bottom-left-radius:3px;border:1px solid rgb(204,204,204);padding:0.5em 0.7em;display:block!important;display:block;padding:0.5em;color:rgb(51,51,51);background-color:rgb(248,248,255);background-repeat:initial initial"><span style="color:rgb(51,51,51);font-weight:bold">import</span> ctypes
<span style="color:rgb(51,51,51);font-weight:bold">import</span> grass.lib.gis <span style="color:rgb(51,51,51);font-weight:bold">as</span> libgis
<span style="color:rgb(51,51,51);font-weight:bold">from</span> grass <span style="color:rgb(51,51,51);font-weight:bold">import</span> script
SEP = <span style="color:rgb(221,17,68)">'\n\n'</span>
c_region = ctypes.pointer(libgis.Cell_head())
<span style="color:rgb(153,153,136);font-style:italic">## read current region </span>
libgis.G_get_set_window(c_region)
print(<span style="color:rgb(221,17,68)">'original'</span>)
print(c_region.contents.ns_res)
print(c_region.contents.rows)
print(c_region.contents.ew_res)
print(c_region.contents.cols)
print(SEP)
<span style="color:rgb(153,153,136);font-style:italic">## change resolution </span>
c_region.contents.ns_res = <span style="color:rgb(0,153,153)">100.</span>
c_region.contents.ew_res = <span style="color:rgb(0,153,153)">100.</span>
<span style="color:rgb(153,153,136);font-style:italic">## adjust </span>
libgis.G_adjust_Cell_head(c_region, <span style="color:rgb(0,153,153)">0</span>, <span style="color:rgb(0,153,153)">0</span>)
print(<span style="color:rgb(221,17,68)">'changed'</span>)
print(c_region.contents.ns_res)
print(c_region.contents.rows)
print(c_region.contents.ew_res)
print(c_region.contents.cols)
print(SEP)
<span style="color:rgb(153,153,136);font-style:italic">## save current </span>
libgis.G_set_window(c_region)
print(script.read_command(<span style="color:rgb(221,17,68)">"g.region"</span>, flags=<span style="color:rgb(221,17,68)">"p"</span>))
print(SEP)
<span style="color:rgb(153,153,136);font-style:italic">## read current region </span>
libgis.G_get_set_window(c_region)
print(<span style="color:rgb(221,17,68)">'after'</span>)
print(c_region.contents.ns_res)
print(c_region.contents.rows)
print(c_region.contents.ew_res)
print(c_region.contents.cols)
print(SEP)
</code></pre>
<p style="margin:1.2em 0px!important">The output is:</p>
<pre style="font-size:0.85em;font-family:Consolas,Inconsolata,Courier,monospace;font-size:1em;line-height:1.2em;margin:1.2em 0px"><code style="font-size:0.85em;font-family:Consolas,Inconsolata,Courier,monospace;margin:0px 0.15em;padding:0px 0.3em;white-space:pre-wrap;border:1px solid rgb(234,234,234);background-color:rgb(248,248,248);border-top-left-radius:3px;border-top-right-radius:3px;border-bottom-right-radius:3px;border-bottom-left-radius:3px;display:inline;white-space:pre-wrap;overflow:auto;border-top-left-radius:3px;border-top-right-radius:3px;border-bottom-right-radius:3px;border-bottom-left-radius:3px;border:1px solid rgb(204,204,204);padding:0.5em 0.7em;display:block!important;display:block;padding:0.5em;color:rgb(51,51,51);background-color:rgb(248,248,255);background-repeat:initial initial">original
<span style="color:rgb(0,153,153)">10.0</span>
<span style="color:rgb(0,153,153)">1350</span>
<span style="color:rgb(0,153,153)">10.0</span>
<span style="color:rgb(0,153,153)">1500</span>
changed
<span style="color:rgb(0,153,153)">100.0</span>
<span style="color:rgb(0,153,153)">135</span>
<span style="color:rgb(0,153,153)">100.0</span>
<span style="color:rgb(0,153,153)">150</span>
projection: <span style="color:rgb(0,153,153)">99</span> (Lambert Conformal Conic)
zone: <span style="color:rgb(0,153,153)">0</span>
datum: nad83
ellipsoid: a=<span style="color:rgb(0,153,153)">6378137</span> es=<span style="color:rgb(0,153,153)">0.006694380022900787</span>
north: <span style="color:rgb(0,153,153)">228500</span>
south: <span style="color:rgb(0,153,153)">215000</span>
west: <span style="color:rgb(0,153,153)">630000</span>
east: <span style="color:rgb(0,153,153)">645000</span>
nsres: <span style="color:rgb(0,153,153)">10</span>
ewres: <span style="color:rgb(0,153,153)">10</span>
rows: <span style="color:rgb(0,153,153)">1350</span>
cols: <span style="color:rgb(0,153,153)">1500</span>
cells: <span style="color:rgb(0,153,153)">2025000</span>
after
<span style="color:rgb(0,153,153)">100.0</span>
<span style="color:rgb(0,153,153)">135</span>
<span style="color:rgb(0,153,153)">100.0</span>
<span style="color:rgb(0,153,153)">150</span>
</code></pre>
<p style="margin:1.2em 0px!important">Any Ideas?</p><span class="HOEnZb"><font color="#888888"><span><font color="#888888"><p style="margin:1.2em 0px!important">Pietro</p></font></span></font></span></div></div></div></div>
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