<html><head></head><body style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space; ">Hi Hai,<div><br></div><div>You should probably bound the variable to be positive. <div>In the parameter section use this, but replace 0.001 and 10 with reasonable lower and upper bounds.</div><div>init_bounded_number x(0.001,10)</div><div><div><br class="webkit-block-placeholder"></div><div><span class="Apple-style-span" style="border-collapse: separate; color: rgb(0, 0, 0); font-family: Helvetica; font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; line-height: normal; orphans: 2; text-align: -webkit-auto; text-indent: 0px; text-transform: none; white-space: normal; widows: 2; word-spacing: 0px; -webkit-border-horizontal-spacing: 0px; -webkit-border-vertical-spacing: 0px; -webkit-text-decorations-in-effect: none; -webkit-text-size-adjust: auto; -webkit-text-stroke-width: 0px; font-size: medium; "><span class="Apple-style-span" style="border-collapse: separate; color: rgb(0, 0, 0); font-family: Helvetica; font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; line-height: normal; orphans: 2; text-indent: 0px; text-transform: none; white-space: normal; widows: 2; word-spacing: 0px; -webkit-border-horizontal-spacing: 0px; -webkit-border-vertical-spacing: 0px; -webkit-text-decorations-in-effect: none; -webkit-text-size-adjust: auto; -webkit-text-stroke-width: 0px; font-size: medium; "><div style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space; ">Mollie</div></span></span>
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<br><div><div>On 30 Jan 2013, at 12:49 AM, Hai Che wrote:</div><br class="Apple-interchange-newline"><blockquote type="cite"><div dir="ltr"><div class="gmail_extra" style="">Dear all,</div><div class="gmail_extra" style=""><br></div><div class="gmail_extra" style="">I kept getting the error message:</div><div class="gmail_extra" style=""><br></div><div class="gmail_extra" style="">
Attempting to take the derivative of sqrt(prevariable x) at x=0<br></div><div class="gmail_extra" style=""><br></div><div class="gmail_extra" style="">after 30-40 iterations using ADMB. I tried different starting values and etc. Nothing helped. Could you help providing some suggestions on this problem?</div>
<div class="gmail_extra" style=""><br></div><div class="gmail_extra" style="">Hai</div></div>
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