<div dir="ltr">Hello.<div><br></div><div>You can use fslove if your equation is exact and leastsq if it is an approximate relationship. But,in the first case you need to have the smae number of parameters than observations and in the second one more observations than parameters, whereas you seem to have less observations (3) than parameters (4): you should have an infinite number of slutions!</div><div><br></div><div>Éric</div></div><div class="gmail_extra"><br><div class="gmail_quote">2015-05-13 19:43 GMT+02:00 Kleper Oliveira Rocha <span dir="ltr"><<a href="mailto:k.o.rocha@gmail.com" target="_blank">k.o.rocha@gmail.com</a>></span>:<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_default" style="font-family:georgia,serif;font-size:small;color:rgb(0,0,153)"><div class="gmail_default">Dear colleagues,</div><div class="gmail_default"><br></div><div class="gmail_default">I want to fit data to an equation like</div><div class="gmail_default"><span style="font-size:11pt;line-height:16.8666667938232px;font-family:Calibri,sans-serif"></span><span style="font-size:11pt;line-height:16.8666667938232px;font-family:Calibri,sans-serif"></span><img src="cid:ii_14bb797234ba7eae" alt="Imagem inline 1" width="175" height="96"><br></div><div class="gmail_default"> where a, beta1, b and beta2 must be determined.</div><div class="gmail_default"><br></div><div class="gmail_default">The data are:</div><div class="gmail_default"><br></div><div class="gmail_default">y Pco PH2</div><div class="gmail_default"><br></div><div class="gmail_default">0.00495 1.0 0.1</div><div class="gmail_default">0.00742 1.0 0.5</div><div class="gmail_default">0.00525 1.0 4.0</div><div class="gmail_default"><br></div><div class="gmail_default">In the book of Fogler (Elements of Chemical Reaction Engineering) I have the answer</div><div class="gmail_default"><br></div><div class="gmail_default">a = 0.02527</div><div class="gmail_default">beta1 = 0.6166</div><div class="gmail_default">b = 2.4872</div><div class="gmail_default">beta2 = 1.0262</div><div class="gmail_default"><br></div><div class="gmail_default">How can I fit the data above to the equation in Scilab?</div><div class="gmail_default"><br></div><div class="gmail_default">Thanks in advance.</div></div><div><div><div dir="ltr"><div><div dir="ltr"><div><div dir="ltr"><div><font style="background-color:rgb(255,255,255)" face="georgia,serif" size="4"><i>- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - </i></font></div><div><font style="background-color:rgb(255,255,255)" face="georgia,serif" size="4"><i>Kleper de Oliveira Rocha</i></font></div>
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