Path: news.mathworks.com!newsfeed-00.mathworks.com!newsfeed2.dallas1.level3.net!news.level3.com!postnews.google.com!glegroupsg2000goo.googlegroups.com!not-for-mail From: =?ISO-8859-1?Q?Ata=EDas_Pereira_Reis?= <ataiasreis@gmail.com> Newsgroups: comp.soft-sys.matlab Subject: Re: Problem solving bvp of Meniscus Date: Mon, 31 Oct 2011 09:24:31 -0700 (PDT) Organization: http://groups.google.com Lines: 34 Message-ID: <24161917.1073.1320078271146.JavaMail.geo-discussion-forums@yqp37> References: <1207681.241.1319819354868.JavaMail.geo-discussion-forums@yqgn17> <j8equl$em1$1@newscl01ah.mathworks.com> <j8fid8$s7g$1@newscl01ah.mathworks.com> Reply-To: comp.soft-sys.matlab@googlegroups.com NNTP-Posting-Host: 164.41.4.26 Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable X-Trace: posting.google.com 1320078370 26731 127.0.0.1 (31 Oct 2011 16:26:10 GMT) X-Complaints-To: groups-abuse@google.com NNTP-Posting-Date: Mon, 31 Oct 2011 16:26:10 +0000 (UTC) Cc: Roger Stafford <ellieandrogerxyzzy@mindspring.com.invalid> In-Reply-To: <j8fid8$s7g$1@newscl01ah.mathworks.com> Complaints-To: groups-abuse@google.com Injection-Info: glegroupsg2000goo.googlegroups.com; posting-host=164.41.4.26; posting-account=wtsldQoAAADbHg04UPiWzuIoOVkAJWvj User-Agent: G2/1.0 X-Google-Web-Client: true Xref: news.mathworks.com comp.soft-sys.matlab:747726 Hello Roger! First off, thank you for your effort in your answer. Anyway, it's not supposed that a=0, because it's related with the height of the meniscus. By the way, I think you didn't considered the fact of y'(0) = -cotg(theta). If a should be zero in this equation, it's a wrong equation. I was trying to solve another equation before, but I have a lot of errors, the graph had never fitted the expected. This equation was: \frac{2y}{a^2} - \frac{z''}{(1+(z')^2)^{3/2}} = 0 I obtained some graphs with this equation (terrible graphics), using the conditions: function res = bvp(ya, yb, a) theta = (pi/180)*30; %thirty degrees res = [ya(2) % z(infinity) yb(2) % z'(infinity) yb(1) + cot(theta)]; % initial angle cotg(theta) that I'd shown before. Well, in this equation, a can not be zero, as it's shown as a divisor. The problem with the graphs is that I obtained a lot of horizontal lines (not what I wanted) or an exponential with a very high value when x = 0. Not the case, because the height is the value of y(0), and it's not very big. The a value should be something greater than 0 and less than 1. The height is obtained knowing the a value, but I don't remember the equation for h. Well, does anyone have an idea how to fix the bug of a horizontal line? I don't know why this happens (well, I showed the returned values in the first post, still that problem). Thank you for all, Regards