simsem and semTools
http://openmx.psyc.virginia.edu/taxonomy/term/45/0
enFunction to add up paths (path tracing rules function)
http://openmx.psyc.virginia.edu/thread/2076
<p>Anyone know of a function to take a RAM model and an entry and exit point and output a total effect?</p>
<p>i.e., given A model m1 = A<->B; B->C; A->C </p>
<p><span class="geshifilter"><code class="rsplus geshifilter-rsplus">pathEffect<span style="color: #080;">(</span>m1, from<span style="color: #080;">=</span><span style="color: #ff0000;">"A"</span>, to<span style="color: #080;">=</span> <span style="color: #ff0000;">"C"</span><span style="color: #080;">)</span></code></span></p>
<p>Would output the product of paths <span class="geshifilter"><code class="rsplus geshifilter-rsplus"><span style="color: #080;">(</span>a<span style="color: #080;">-</span><span style="color: #0000FF; font-weight: bold;">c</span><span style="color: #080;">)</span> <span style="color: #080;">+</span> <span style="color: #080;">(</span>a<span style="color: #080;">-</span>b <span style="color: #080;">*</span> b<span style="color: #080;">-</span><span style="color: #0000FF; font-weight: bold;">c</span><span style="color: #080;">)</span></code></span></p>
<p>If not, it might be a handy addition, and encourage people to report the expected effects in their model rather than just fit. i.e., "All things being equal, this model of our theory suggests that an increase of 50 kg/day of saccharin would decrease lifespan by 1-second, via the following pathways..."</p>
http://openmx.psyc.virginia.edu/thread/2076#commentssimsem and semToolsSat, 20 Apr 2013 14:26:19 +0000tbates2076 at http://openmx.psyc.virginia.edusimsem and semTools
http://openmx.psyc.virginia.edu/thread/2070
<p>Welcome to the simsem and semTools forum! simsem and semTools are R packages (available on CRAN) that provide additional functionality for structural equation modeling in R.</p>
<p>simsem provides comprehensive simulation functionality for structural equation modeling. simsem allows data generation based on a user specified model, analyses of generated data, and storage and processing of simulation results. Data generation and analysis models using can be specified using lavaan syntax, or OpenMx model specifications, or a set of matrices. </p>
<p>For further details on simsem see: <a href="http://simsem.org" title="http://simsem.org">http://simsem.org</a></p>
<p>semTools is a package comprised of useful functions for structural equation modeling in R. semTools is designed to be a user supported package and all users of SEM and R are encouraged to submit functions of ideas for additional functions. semTools includes the functions, fitMeasuresMx, nullMx, and saturateMx, which compute fit measures, a null model and a saturated model with OpenMx.</p>
<p>For more information on semTools see: <a href="https://github.com/simsem/semTools/wiki" title="https://github.com/simsem/semTools/wiki">https://github.com/simsem/semTools/wiki</a></p>
<p>Thanks,</p>
<p>-Alex</p>
http://openmx.psyc.virginia.edu/thread/2070#commentssimsem and semToolsMon, 15 Apr 2013 18:27:17 +0000Aschoemann2070 at http://openmx.psyc.virginia.edu