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<?xml version="1.0" encoding="ISO-8859-1" standalone="no"?>
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<!DOCTYPE MAN SYSTEM "../../manrev.dtd">
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<LANGUAGE>eng</LANGUAGE>
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<TITLE>odeoptions</TITLE>
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<TYPE>Scilab Function</TYPE>
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<DATE>February 1998</DATE>
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<SHORT_DESCRIPTION name="odeoptions"> set options for ode solvers</SHORT_DESCRIPTION>
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<CALLING_SEQUENCE_ITEM>odeoptions() </CALLING_SEQUENCE_ITEM>
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This function interactively displays a command which
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should be executed to set various options of ode solvers.
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The global variable <VERB>%ODEOPTIONS</VERB> sets the options.</P>
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CAUTION: the <VERB>ode</VERB> function checks if this variable
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exists and in this case it uses it. For using default
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values you should clear this variable. Note that <VERB>odeoptions</VERB>
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does not create this variable. To create it you must execute
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the command line displayed by <VERB>odeoptions</VERB>.</P>
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The variable <VERB>%ODEOPTIONS</VERB> is a vector with the following elements:</P>
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[itask,tcrit,h0,hmax,hmin,jactyp,mxstep,maxordn,maxords,ixpr,ml,mu]
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The default value is:</P>
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[1,0,0,%inf,0,2,500,12,5,0,-1,-1]
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The meaning of the elements is described below.</P>
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1 : normal computation at specified times
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2 : computation at mesh points (given in first row of output of <VERB>ode</VERB>)
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3 : one step at one internal mesh point and return
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4 : normal computation without overshooting <VERB>tcrit</VERB>
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5 : one step, without passing <VERB>tcrit</VERB>, and return</P>
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assumes <VERB>itask</VERB> equals 4 or 5, described above</P>
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<P><VERB>jactype</VERB>
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0 : functional iterations, no jacobian used (<VERB>"adams"</VERB> or
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<VERB>"stiff"</VERB> only)
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1 : user-supplied full jacobian
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2 : internally generated full jacobian
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3 : internally generated diagonal jacobian (<VERB>"adams"</VERB> or
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<VERB>"stiff"</VERB> only)
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4 : user-supplied banded jacobian (see <VERB>ml</VERB> and <VERB>mu</VERB> below)
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5 : internally generated banded jacobian (<VERB>see</VERB> ml and <VERB>mu</VERB> below)</P>
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<P><VERB>maxordn</VERB>
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maximum non-stiff order allowed, at most 12</P>
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<P><VERB>maxords</VERB>
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maximum stiff order allowed, at most 5</P>
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print level, 0 or 1</P>
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<P><VERB>ml</VERB>,<VERB>mu</VERB>
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If <VERB>jactype</VERB> equals 4 or 5, <VERB>ml</VERB> and <VERB>mu</VERB> are the lower
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and upper half-bandwidths of the banded jacobian: the band is the
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i,j's with i-ml <= j <= ny-1.
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If <VERB>jactype</VERB> equals 4 the jacobian function must return
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a matrix J which is ml+mu+1 x ny (where ny=dim of y in ydot=f(t,y))
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such that column 1 of J is made of mu zeros followed by
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df1/dy1, df2/dy1, df3/dy1, ... (1+ml possibly non-zero entries)
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column 2 is made of mu-1 zeros followed by df1/dx2, df2/dx2, etc</P>