 4PL mixed #########################################</span>

<span class='co'># some threshold parameters</span>
<span class='va'>THRES</span>  <span class='op'>&lt;-</span> <span class='fu'><a href='https://rdrr.io/r/base/matrix.html'>matrix</a></span><span class='op'>(</span><span class='fu'><a href='https://rdrr.io/r/base/c.html'>c</a></span><span class='op'>(</span><span class='op'>-</span><span class='fl'>2</span>,<span class='op'>-</span><span class='fl'>1.23</span>,<span class='fl'>1.11</span>,<span 