ex">Source: <a href="https://github.com/dcousin3/superb/blob/HEAD/R/grd.R" class="external-link"><code>R/grd.R</code></a></small>
    <div class="hidden name"><code>slope.Rd</code></div>
    </div>

    <div class="ref-description">
    <p>There is four ways that effects can be defined
in GRD. `"factor" = slope(s)` will vary the means by an amount of s for
each step of the factor; `"factor" = extent(s)` will vary the means
uniformly so that there is a difference of s between the first and
the last factor le