https://communities.sas.com/t5/SAS-IML-Software-and-Matrix/get-the-root-of-a-complicated-equation/m-p/16969#M45 How to get the root of a complicated equation in IML? Is there any function or call function to do that? <BR /> Thanks alot! Mon, 20 Jun 2011 00:44:41 GMT Steve_Shanghai 2011-06-20T00:44:41Z https://communities.sas.com/t5/SAS-IML-Software-and-Matrix/get-the-root-of-a-complicated-equation/m-p/16969#M45 How to get the root of a complicated equation in IML? Is there any function or call function to do that? <BR /> Thanks alot! Mon, 20 Jun 2011 00:44:41 GMT https://communities.sas.com/t5/SAS-IML-Software-and-Matrix/get-the-root-of-a-complicated-equation/m-p/16969#M45 Steve_Shanghai 2011-06-20T00:44:41Z https://communities.sas.com/t5/SAS-IML-Software-and-Matrix/get-the-root-of-a-complicated-equation/m-p/16970#M46 Depends if the function is one-variable or several variables. Also if polynomial or general nonlinear equation. <BR /> 1) For one variable and polynomial, use POLYROOT. This finds real and complex roots.<BR /> 2) For finding the real roots of general functions, see Example 9.2 of the SAS/IML doc:<BR /> <A href="http://support.sas.com/documentation/cdl/en/imlug/63541/HTML/default/viewer.htm#imlug_genstatexpls_sect004.htm" target="_blank">http://support.sas.com/documentation/cdl/en/imlug/63541/HTML/default/viewer.htm#imlug_genstatexpls_sect004.htm</A><BR /> <BR /> The Newton-Raphson method (2) will find one root for each initial condition, so if you are trying to find multiple roots, you might want to vary the initial condition. Mon, 20 Jun 2011 17:05:25 GMT https://communities.sas.com/t5/SAS-IML-Software-and-Matrix/get-the-root-of-a-complicated-equation/m-p/16970#M46 Rick_SAS 2011-06-20T17:05:25Z