<div dir="ltr">For this problem, though, I don't think contouring is what you want. I think you'd be better off looking for some spatial consistency in the gradient field directly rather than going through contours.<div><br></div><div>Ryan</div></div><div class="gmail_extra"><br><div class="gmail_quote">On Wed, Oct 18, 2017 at 2:59 PM, ashwin .D <span dir="ltr"><<a href="mailto:winash12@gmail.com" target="_blank">winash12@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><div><div>Hello,<br></div>         I have data on a 2d lat lon grid(equal grid spacing) in terms of laitude and longitude and heights as enclosed in the image. I need the coordinates(in terms of latitude and longitude) of the contours( as shown in red in the image). From this answer - <a href="https://stackoverflow.com/questions/18304722/python-find-contour-lines-from-matplotlib-pyplot-contour/" target="_blank">https://stackoverflow.com/<wbr>questions/18304722/python-<wbr>find-contour-lines-from-<wbr>matplotlib-pyplot-contour/</a> will this give me what I am looking for or is there a scaling required to latitude and longitude that I need to include? <br><br></div>Best regards,<br></div>Ashwin. <br><div><div><pre class="m_5506613425912259597gmail-lang-py m_5506613425912259597gmail-prettyprint m_5506613425912259597gmail-prettyprinted"><code><span class="m_5506613425912259597gmail-kwd">import</span><span class="m_5506613425912259597gmail-pln"> numpy </span><span class="m_5506613425912259597gmail-kwd">as</span><span class="m_5506613425912259597gmail-pln"> np

</span><span class="m_5506613425912259597gmail-kwd">def</span><span class="m_5506613425912259597gmail-pln"> get_contour_verts</span><span class="m_5506613425912259597gmail-pun">(</span><span class="m_5506613425912259597gmail-pln">cn</span><span class="m_5506613425912259597gmail-pun">):</span><span class="m_5506613425912259597gmail-pln">
    contours </span><span class="m_5506613425912259597gmail-pun">=</span><span class="m_5506613425912259597gmail-pln"> </span><span class="m_5506613425912259597gmail-pun">[]</span><span class="m_5506613425912259597gmail-pln">
    </span><span class="m_5506613425912259597gmail-com"># for each contour line</span><span class="m_5506613425912259597gmail-pln">
    </span><span class="m_5506613425912259597gmail-kwd">for</span><span class="m_5506613425912259597gmail-pln"> cc </span><span class="m_5506613425912259597gmail-kwd">in</span><span class="m_5506613425912259597gmail-pln"> cn</span><span class="m_5506613425912259597gmail-pun">.</span><span class="m_5506613425912259597gmail-pln">collections</span><span class="m_5506613425912259597gmail-pun">:</span><span class="m_5506613425912259597gmail-pln">
        paths </span><span class="m_5506613425912259597gmail-pun">=</span><span class="m_5506613425912259597gmail-pln"> </span><span class="m_5506613425912259597gmail-pun">[]</span><span class="m_5506613425912259597gmail-pln">
        </span><span class="m_5506613425912259597gmail-com"># for each separate section of the contour line</span><span class="m_5506613425912259597gmail-pln">
        </span><span class="m_5506613425912259597gmail-kwd">for</span><span class="m_5506613425912259597gmail-pln"> pp </span><span class="m_5506613425912259597gmail-kwd">in</span><span class="m_5506613425912259597gmail-pln"> cc</span><span class="m_5506613425912259597gmail-pun">.</span><span class="m_5506613425912259597gmail-pln">get_paths</span><span class="m_5506613425912259597gmail-pun">():</span><span class="m_5506613425912259597gmail-pln">
            xy </span><span class="m_5506613425912259597gmail-pun">=</span><span class="m_5506613425912259597gmail-pln"> </span><span class="m_5506613425912259597gmail-pun">[]</span><span class="m_5506613425912259597gmail-pln">
            </span><span class="m_5506613425912259597gmail-com"># for each segment of that section</span><span class="m_5506613425912259597gmail-pln">
            </span><span class="m_5506613425912259597gmail-kwd">for</span><span class="m_5506613425912259597gmail-pln"> vv </span><span class="m_5506613425912259597gmail-kwd">in</span><span class="m_5506613425912259597gmail-pln"> pp</span><span class="m_5506613425912259597gmail-pun">.</span><span class="m_5506613425912259597gmail-pln">iter_segments</span><span class="m_5506613425912259597gmail-pun">():</span><span class="m_5506613425912259597gmail-pln">
                xy</span><span class="m_5506613425912259597gmail-pun">.</span><span class="m_5506613425912259597gmail-pln">append</span><span class="m_5506613425912259597gmail-pun">(</span><span class="m_5506613425912259597gmail-pln">vv</span><span class="m_5506613425912259597gmail-pun">[</span><span class="m_5506613425912259597gmail-lit">0</span><span class="m_5506613425912259597gmail-pun">])</span><span class="m_5506613425912259597gmail-pln">
            paths</span><span class="m_5506613425912259597gmail-pun">.</span><span class="m_5506613425912259597gmail-pln">append</span><span class="m_5506613425912259597gmail-pun">(</span><span class="m_5506613425912259597gmail-pln">np</span><span class="m_5506613425912259597gmail-pun">.</span><span class="m_5506613425912259597gmail-pln">vstack</span><span class="m_5506613425912259597gmail-pun">(</span><span class="m_5506613425912259597gmail-pln">xy</span><span class="m_5506613425912259597gmail-pun">))</span><span class="m_5506613425912259597gmail-pln">
        contours</span><span class="m_5506613425912259597gmail-pun">.</span><span class="m_5506613425912259597gmail-pln">append</span><span class="m_5506613425912259597gmail-pun">(</span><span class="m_5506613425912259597gmail-pln">paths</span><span class="m_5506613425912259597gmail-pun">)</span><span class="m_5506613425912259597gmail-pln">

    </span><span class="m_5506613425912259597gmail-kwd">return</span><span class="m_5506613425912259597gmail-pln"> contours<br><br></span></code></pre><pre class="m_5506613425912259597gmail-lang-py m_5506613425912259597gmail-prettyprint m_5506613425912259597gmail-prettyprinted"><code><span class="m_5506613425912259597gmail-pln"><br></span></code></pre></div></div></div>
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<br></blockquote></div><br><br clear="all"><div><br></div>-- <br><div class="gmail_signature" data-smartmail="gmail_signature"><div dir="ltr"><div>Ryan May<br><br></div></div></div>
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