<!DOCTYPE html>
<!-- Generated by pkgdown: do not edit by hand --><html lang="en"><head><meta http-equiv="Content-Type" content="text/html; charset=UTF-8"><meta charset="utf-8"><meta http-equiv="X-UA-Compatible" content="IE=edge"><meta name="viewport" content="width=device-width, initial-scale=1, shrink-to-fit=no"><meta name="description" content="Easily compute planned contrast analyses (pairwise
comparisons similar to t-tests but more powerful when more than
2 groups), and format in publication-ready format. Supports only
three groups for the moment. In this particular case, the
confidence intervals are bootstraped on chosen effect size
(default to Cohen's d)."><title>Easy planned contrasts â€” nice_contrasts â€¢ rempsyc</title><!-- favicons --><link rel="icon" type="image/png" sizes="16x16" href="../favicon-16x16.png"><link rel="icon" type="image/png" sizes="32x32" href="../favicon-32x32.png"><link rel="apple-touch-icon" type="image/png" sizes="180x180" href="../apple-touch-icon.png"><link rel="apple-touch-icon" type="image/png" sizes="120x120" href="../apple-touch-icon-120x120.png"><link rel="apple-touch-icon" type="image/png" sizes="76x76" href="../apple-touch-icon-76x76.png"><link rel="apple-touch-icon" type="image/png" sizes="60x60" href="../apple-touch-icon-60x60.png"><script src="../deps/jquery-3.6.0/jquery-3.6.0.min.js"></script><meta name="viewport" content="width=device-width, initial-scale=1, shrink-to-fit=no"><link href="../deps/bootstrap-5.2.2/bootstrap.min.css" rel="stylesheet"><script src="../deps/bootstrap-5.2.2/bootstrap.bundle.min.js"></script><!-- Font Awesome icons --><link rel="stylesheet" href="https://cdnjs.cloudflare.com/ajax/libs/font-awesome/5.12.1/css/all.min.css" integrity="sha256-mmgLkCYLUQbXn0B1SRqzHar6dCnv9oZFPEC1g1cwlkk=" crossorigin="anonymous"><link rel="stylesheet" href="https://cdnjs.cloudflare.com/ajax/libs/font-awesome/5.12.1/css/v4-shims.min.css" integrity="sha256-wZjR52fzng1pJHwx4aV2AO3yyTOXrcDW7jBpJtTwVxw=" crossorigin="anonymous"><!-- bootstrap-toc --><script src="https://cdn.jsdelivr.net/gh/afeld/bootstrap-toc@v1.0.1/dist/bootstrap-toc.min.js" integrity="sha256-4veVQbu7//Lk5TSmc7YV48MxtMy98e26cf5MrgZYnwo=" crossorigin="anonymous"></script><!-- headroom.js --><script src="https://cdnjs.cloudflare.com/ajax/libs/headroom/0.11.0/headroom.min.js" integrity="sha256-AsUX4SJE1+yuDu5+mAVzJbuYNPHj/WroHuZ8Ir/CkE0=" crossorigin="anonymous"></script><script src="https://cdnjs.cloudflare.com/ajax/libs/headroom/0.11.0/jQuery.headroom.min.js" integrity="sha256-ZX/yNShbjqsohH1k95liqY9Gd8uOiE1S4vZc+9KQ1K4=" crossorigin="anonymous"></script><!-- clipboard.js --><script src="https://cdnjs.cloudflare.com/ajax/libs/clipboard.js/2.0.6/clipboard.min.js" integrity="sha256-inc5kl9MA1hkeYUt+EC3BhlIgyp/2jDIyBLS6k3UxPI=" crossorigin="anonymous"></script><!-- search --><script src="https://cdnjs.cloudflare.com/ajax/libs/fuse.js/6.4.6/fuse.js" integrity="sha512-zv6Ywkjyktsohkbp9bb45V6tEMoWhzFzXis+LrMehmJZZSys19Yxf1dopHx7WzIKxr5tK2dVcYmaCk2uqdjF4A==" crossorigin="anonymous"></script><script src="https://cdnjs.cloudflare.com/ajax/libs/autocomplete.js/0.38.0/autocomplete.jquery.min.js" integrity="sha512-GU9ayf+66Xx2TmpxqJpliWbT5PiGYxpaG8rfnBEk1LL8l1KGkRShhngwdXK1UgqhAzWpZHSiYPc09/NwDQIGyg==" crossorigin="anonymous"></script><script src="https://cdnjs.cloudflare.com/ajax/libs/mark.js/8.11.1/mark.min.js" integrity="sha512-5CYOlHXGh6QpOFA/TeTylKLWfB3ftPsde7AnmhuitiTX4K5SqCLBeKro6sPS8ilsz1Q4NRx3v8Ko2IBiszzdww==" crossorigin="anonymous"></script><!-- pkgdown --><script src="../pkgdown.js"></script><meta property="og:title" content="Easy planned contrasts â€” nice_contrasts"><meta property="og:description" content="Easily compute planned contrast analyses (pairwise
comparisons similar to t-tests but more powerful when more than
2 groups), and format in publication-ready format. Supports only
three groups for the moment. In this particular case, the
confidence intervals are bootstraped on chosen effect size
(default to Cohen's d)."><meta property="og:image" content="https://rempsyc.remi-theriault.com/logo.png"><!-- mathjax --><script src="https://cdnjs.cloudflare.com/ajax/libs/mathjax/2.7.5/MathJax.js" integrity="sha256-nvJJv9wWKEm88qvoQl9ekL2J+k/RWIsaSScxxlsrv8k=" crossorigin="anonymous"></script><script src="https://cdnjs.cloudflare.com/ajax/libs/mathjax/2.7.5/config/TeX-AMS-MML_HTMLorMML.js" integrity="sha256-84DKXVJXs0/F8OTMzX4UR909+jtl4G7SPypPavF+GfA=" crossorigin="anonymous"></script><!--[if lt IE 9]>
<script src="https://oss.maxcdn.com/html5shiv/3.7.3/html5shiv.min.js"></script>
<script src="https://oss.maxcdn.com/respond/1.4.2/respond.min.js"></script>
<![endif]--><!-- Global site tag (gtag.js) - Google Analytics --><script async src="https://www.googletagmanager.com/gtag/js?id=G-274QZTFL23"></script><script>
  window.dataLayer = window.dataLayer || [];
  function gtag(){dataLayer.push(arguments);}
  gtag('js', new Date());

  gtag('config', 'G-274QZTFL23');
</script></head><body>
    <a href="#main" class="visually-hidden-focusable">Skip to contents</a>
    

    <nav class="navbar fixed-top navbar-default navbar-expand-lg bg-light"><div class="container">
    
    <a class="navbar-brand me-2" href="../index.html">rempsyc</a>

    <small class="nav-text text-muted me-auto" data-bs-toggle="tooltip" data-bs-placement="bottom" title="">0.1.1.3</small>

    
    <button class="navbar-toggler" type="button" data-bs-toggle="collapse" data-bs-target="#navbar" aria-controls="navbar" aria-expanded="false" aria-label="Toggle navigation">
      <span class="navbar-toggler-icon"></span>
    </button>

    <div id="navbar" class="collapse navbar-collapse ms-3">
      <ul class="navbar-nav me-auto"><li class="nav-item">
  <a class="nav-link" href="../index.html">
    <span class="fa fa-home"></span>
     
  </a>
</li>
<li class="nav-item dropdown">
  <a href="#" class="nav-link dropdown-toggle" data-bs-toggle="dropdown" role="button" aria-expanded="false" aria-haspopup="true" id="dropdown-tutorials">Tutorials</a>
  <div class="dropdown-menu" aria-labelledby="dropdown-tutorials">
    <h6 class="dropdown-header" data-toc-skip>âˆš STATISTICS</h6>
    <a class="dropdown-item" href="../articles/table.html">APA tables</a>
    <a class="dropdown-item" href="../articles/t-test.html">t tests</a>
    <a class="dropdown-item" href="../articles/contrasts.html">Planned contrasts</a>
    <a class="dropdown-item" href="../articles/moderation.html">Moderations</a>
    <a class="dropdown-item" href="../articles/randomize.html">Randomization</a>
    <h6 class="dropdown-header" data-toc-skip>ðŸ“Š VISUALIZATION</h6>
    <a class="dropdown-item" href="../articles/violin.html">Violin plots</a>
    <a class="dropdown-item" href="../articles/scatter.html">Scatter plots</a>
    <a class="dropdown-item" href="../articles/circles.html">Overlapping circles</a>
    <a class="dropdown-item" href="../articles/assumptions.html">Assumptions</a>
  </div>
</li>
<li class="active nav-item">
  <a class="nav-link" href="../reference/index.html">Functions</a>
</li>
<li class="nav-item">
  <a class="nav-link" href="../news/index.html">News</a>
</li>
<li class="nav-item">
  <a class="nav-link" href="../TODOS.html">To-dos</a>
</li>
<li class="nav-item">
  <a class="nav-link" href="../articles/featured.html">Featured In</a>
</li>
      </ul><form class="form-inline my-2 my-lg-0" role="search">
        <input type="search" class="form-control me-sm-2" aria-label="Toggle navigation" name="search-input" data-search-index="../search.json" id="search-input" placeholder="Search for" autocomplete="off"></form>

      <ul class="navbar-nav"><li class="nav-item">
  <a class="external-link nav-link" href="https://lavaanExtra.remi-theriault.com/" aria-label="lavaanExtra">lavaanExtra</a>
</li>
<li class="nav-item">
  <a class="external-link nav-link" href="https://twitter.com/rempsyc" aria-label="Twitter">
    <span class="fa fa-twitter"></span>
     
  </a>
</li>
<li class="nav-item">
  <a class="external-link nav-link" href="https://github.com/rempsyc/rempsyc/" aria-label="GitHub">
    <span class="fa fa-github"></span>
     
  </a>
</li>
<li class="nav-item">
  <a class="external-link nav-link" href="https://github.com/sponsors/rempsyc" aria-label="Donate">
    <span class="fa fa-coffee"></span>
     
  </a>
</li>
      </ul></div>

    
  </div>
</nav><div class="container template-reference-topic">
<div class="row">
  <main id="main" class="col-md-9"><div class="page-header">
      <img src="../logo.png" class="logo" alt=""><h1>Easy planned contrasts</h1>
      <small class="dont-index">Source: <a href="https://github.com/rempsyc/rempsyc/blob/HEAD/R/nice_contrasts.R" class="external-link"><code>R/nice_contrasts.R</code></a></small>
      <div class="d-none name"><code>nice_contrasts.Rd</code></div>
    </div>

    <div class="ref-description section level2">
    <p>Easily compute planned contrast analyses (pairwise
comparisons similar to t-tests but more powerful when more than
2 groups), and format in publication-ready format. Supports only
three groups for the moment. In this particular case, the
confidence intervals are bootstraped on chosen effect size
(default to Cohen's d).</p>
    </div>

    <div class="section level2">
    <h2 id="ref-usage">Usage<a class="anchor" aria-label="anchor" href="#ref-usage"></a></h2>
    <div class="sourceCode"><pre class="sourceCode r"><code><span><span class="fu">nice_contrasts</span><span class="op">(</span></span>
<span>  <span class="va">response</span>,</span>
<span>  <span class="va">group</span>,</span>
<span>  covariates <span class="op">=</span> <span class="cn">NULL</span>,</span>
<span>  <span class="va">data</span>,</span>
<span>  effect.type <span class="op">=</span> <span class="st">"cohens.d"</span>,</span>
<span>  bootstraps <span class="op">=</span> <span class="fl">2000</span>,</span>
<span>  <span class="va">...</span></span>
<span><span class="op">)</span></span></code></pre></div>
    </div>

    <div class="section level2">
    <h2 id="arguments">Arguments<a class="anchor" aria-label="anchor" href="#arguments"></a></h2>
    <dl><dt>response</dt>
<dd><p>The dependent variable.</p></dd>


<dt>group</dt>
<dd><p>The group for the comparison.</p></dd>


<dt>covariates</dt>
<dd><p>The desired covariates in the model.</p></dd>


<dt>data</dt>
<dd><p>The data frame.</p></dd>


<dt>effect.type</dt>
<dd><p>What effect size type to use. One of "cohens.d" (default),
"akp.robust.d", "unstandardized", "hedges.g", "cohens.d.sigma", or "r".</p></dd>


<dt>bootstraps</dt>
<dd><p>The number of bootstraps to use for the confidence interval</p></dd>


<dt>...</dt>
<dd><p>Arguments passed to <a href="https://rdrr.io/pkg/bootES/man/bootES.html" class="external-link">bootES::bootES</a>.</p></dd>

</dl></div>
    <div class="section level2">
    <h2 id="value">Value<a class="anchor" aria-label="anchor" href="#value"></a></h2>
    

<p>A dataframe, with the selected dependent variable(s), comparisons of
interest, degrees of freedom, t-values, p-values, robust Cohen's d
(dR), and the lower and upper 95% confidence intervals of the
effect size (i.e., dR).</p>
    </div>
    <div class="section level2">
    <h2 id="details">Details<a class="anchor" aria-label="anchor" href="#details"></a></h2>
    <p>Statistical power is lower with the standard <em>t</em> test
compared than it is with the planned contrast version for two
reasons: a) the sample size is smaller with the <em>t</em> test,
because only the cases in the two groups are selected; and b)
in the planned contrast the error term is smaller than it is
with the standard <em>t</em> test because it is based on all the cases
(<a href="https://web.pdx.edu/~newsomj/uvclass/ho_planned%20contrasts.pdf" class="external-link">source</a>).</p>
<p>The effect size and confidence interval are calculated via
<a href="https://rdrr.io/pkg/bootES/man/bootES.html" class="external-link">bootES::bootES</a>.</p>
<p>For the <em>easystats</em> equivalent, see:
<code><a href="https://easystats.github.io/modelbased/reference/estimate_contrasts.html" class="external-link">modelbased::estimate_contrasts()</a></code>.</p>
    </div>
    <div class="section level2">
    <h2 id="see-also">See also<a class="anchor" aria-label="anchor" href="#see-also"></a></h2>
    <div class="dont-index"><p><code><a href="nice_lm_contrasts.html">nice_lm_contrasts</a></code>,
Tutorial: <a href="https://rempsyc.remi-theriault.com/articles/contrasts">https://rempsyc.remi-theriault.com/articles/contrasts</a></p></div>
    </div>

    <div class="section level2">
    <h2 id="ref-examples">Examples<a class="anchor" aria-label="anchor" href="#ref-examples"></a></h2>
    <div class="sourceCode"><pre class="sourceCode r"><code><span class="r-in"><span><span class="co"># Basic example</span></span></span>
<span class="r-in"><span><span class="fu">nice_contrasts</span><span class="op">(</span></span></span>
<span class="r-in"><span>  data <span class="op">=</span> <span class="va">mtcars</span>,</span></span>
<span class="r-in"><span>  response <span class="op">=</span> <span class="st">"mpg"</span>,</span></span>
<span class="r-in"><span>  group <span class="op">=</span> <span class="st">"cyl"</span>,</span></span>
<span class="r-in"><span>  bootstraps <span class="op">=</span> <span class="fl">200</span></span></span>
<span class="r-in"><span><span class="op">)</span></span></span>
<span class="r-wrn co"><span class="r-pr">#&gt;</span> <span class="warning">Warning: </span>extreme order statistics used as endpoints</span>
<span class="r-wrn co"><span class="r-pr">#&gt;</span> <span class="warning">Warning: </span>extreme order statistics used as endpoints</span>
<span class="r-out co"><span class="r-pr">#&gt;</span>   Dependent Variable Comparison df        t            p        d  CI_lower</span>
<span class="r-out co"><span class="r-pr">#&gt;</span> 1                mpg      4 - 8 29 8.904534 8.568209e-10 3.587739 2.5429025</span>
<span class="r-out co"><span class="r-pr">#&gt;</span> 2                mpg      6 - 8 29 3.111825 4.152209e-03 1.440495 0.7896218</span>
<span class="r-out co"><span class="r-pr">#&gt;</span> 3                mpg      4 - 6 29 4.441099 1.194696e-04 2.147244 1.3259681</span>
<span class="r-out co"><span class="r-pr">#&gt;</span>   CI_upper</span>
<span class="r-out co"><span class="r-pr">#&gt;</span> 1 4.366010</span>
<span class="r-out co"><span class="r-pr">#&gt;</span> 2 1.883638</span>
<span class="r-out co"><span class="r-pr">#&gt;</span> 3 3.295447</span>
<span class="r-in"><span><span class="co"># \donttest{</span></span></span>
<span class="r-in"><span><span class="fu">nice_contrasts</span><span class="op">(</span></span></span>
<span class="r-in"><span>  data <span class="op">=</span> <span class="va">mtcars</span>,</span></span>
<span class="r-in"><span>  response <span class="op">=</span> <span class="st">"disp"</span>,</span></span>
<span class="r-in"><span>  group <span class="op">=</span> <span class="st">"gear"</span></span></span>
<span class="r-in"><span><span class="op">)</span></span></span>
<span class="r-wrn co"><span class="r-pr">#&gt;</span> <span class="warning">Warning: </span>extreme order statistics used as endpoints</span>
<span class="r-out co"><span class="r-pr">#&gt;</span>   Dependent Variable Comparison df         t            p          d</span>
<span class="r-out co"><span class="r-pr">#&gt;</span> 1               disp      3 - 5 29  2.916870 6.759287e-03  1.5062653</span>
<span class="r-out co"><span class="r-pr">#&gt;</span> 2               disp      4 - 5 29 -1.816053 7.971420e-02 -0.9666682</span>
<span class="r-out co"><span class="r-pr">#&gt;</span> 3               disp      3 - 4 29  6.385087 5.569503e-07  2.4729335</span>
<span class="r-out co"><span class="r-pr">#&gt;</span>      CI_lower  CI_upper</span>
<span class="r-out co"><span class="r-pr">#&gt;</span> 1 -0.02092123 3.0623835</span>
<span class="r-out co"><span class="r-pr">#&gt;</span> 2 -2.54126362 0.1223233</span>
<span class="r-out co"><span class="r-pr">#&gt;</span> 3  1.39861017 3.2630773</span>
<span class="r-in"><span></span></span>
<span class="r-in"><span><span class="co"># Multiple dependent variables</span></span></span>
<span class="r-in"><span><span class="fu">nice_contrasts</span><span class="op">(</span></span></span>
<span class="r-in"><span>  data <span class="op">=</span> <span class="va">mtcars</span>,</span></span>
<span class="r-in"><span>  response <span class="op">=</span> <span class="fu"><a href="https://rdrr.io/r/base/c.html" class="external-link">c</a></span><span class="op">(</span><span class="st">"mpg"</span>, <span class="st">"disp"</span>, <span class="st">"hp"</span><span class="op">)</span>,</span></span>
<span class="r-in"><span>  group <span class="op">=</span> <span class="st">"cyl"</span></span></span>
<span class="r-in"><span><span class="op">)</span></span></span>
<span class="r-out co"><span class="r-pr">#&gt;</span>   Dependent Variable Comparison df          t            p         d   CI_lower</span>
<span class="r-out co"><span class="r-pr">#&gt;</span> 1                mpg      4 - 8 29   8.904534 8.568209e-10  3.587739  2.7082311</span>
<span class="r-out co"><span class="r-pr">#&gt;</span> 2                mpg      6 - 8 29   3.111825 4.152209e-03  1.440495  0.8114357</span>
<span class="r-out co"><span class="r-pr">#&gt;</span> 3                mpg      4 - 6 29   4.441099 1.194696e-04  2.147244  1.3096890</span>
<span class="r-out co"><span class="r-pr">#&gt;</span> 4               disp      4 - 8 29 -11.920787 1.064054e-12 -4.803022 -5.7174536</span>
<span class="r-out co"><span class="r-pr">#&gt;</span> 5               disp      6 - 8 29  -7.104461 8.117219e-08 -3.288726 -4.2619982</span>
<span class="r-out co"><span class="r-pr">#&gt;</span> 6               disp      4 - 6 29  -3.131986 3.945539e-03 -1.514296 -2.2028453</span>
<span class="r-out co"><span class="r-pr">#&gt;</span> 7                 hp      4 - 8 29  -8.285112 3.915144e-09 -3.338167 -4.2755262</span>
<span class="r-out co"><span class="r-pr">#&gt;</span> 8                 hp      6 - 8 29  -4.952403 2.895434e-05 -2.292517 -3.1048697</span>
<span class="r-out co"><span class="r-pr">#&gt;</span> 9                 hp      4 - 6 29  -2.162695 3.894886e-02 -1.045650 -1.7383547</span>
<span class="r-out co"><span class="r-pr">#&gt;</span>     CI_upper</span>
<span class="r-out co"><span class="r-pr">#&gt;</span> 1  4.5934966</span>
<span class="r-out co"><span class="r-pr">#&gt;</span> 2  1.9738389</span>
<span class="r-out co"><span class="r-pr">#&gt;</span> 3  3.0295578</span>
<span class="r-out co"><span class="r-pr">#&gt;</span> 4 -3.8406127</span>
<span class="r-out co"><span class="r-pr">#&gt;</span> 5 -2.3305573</span>
<span class="r-out co"><span class="r-pr">#&gt;</span> 6 -0.8441953</span>
<span class="r-out co"><span class="r-pr">#&gt;</span> 7 -2.4421783</span>
<span class="r-out co"><span class="r-pr">#&gt;</span> 8 -1.3244859</span>
<span class="r-out co"><span class="r-pr">#&gt;</span> 9 -0.4461889</span>
<span class="r-in"><span></span></span>
<span class="r-in"><span><span class="co"># Adding covariates</span></span></span>
<span class="r-in"><span><span class="fu">nice_contrasts</span><span class="op">(</span></span></span>
<span class="r-in"><span>  data <span class="op">=</span> <span class="va">mtcars</span>,</span></span>
<span class="r-in"><span>  response <span class="op">=</span> <span class="st">"mpg"</span>,</span></span>
<span class="r-in"><span>  group <span class="op">=</span> <span class="st">"cyl"</span>,</span></span>
<span class="r-in"><span>  covariates <span class="op">=</span> <span class="fu"><a href="https://rdrr.io/r/base/c.html" class="external-link">c</a></span><span class="op">(</span><span class="st">"disp"</span>, <span class="st">"hp"</span><span class="op">)</span></span></span>
<span class="r-in"><span><span class="op">)</span></span></span>
<span class="r-out co"><span class="r-pr">#&gt;</span>   Dependent Variable Comparison df          t          p        d  CI_lower</span>
<span class="r-out co"><span class="r-pr">#&gt;</span> 1                mpg      4 - 8 27  0.7506447 0.45935889 3.587739 2.7395467</span>
<span class="r-out co"><span class="r-pr">#&gt;</span> 2                mpg      6 - 8 27 -0.6550186 0.51799786 1.440495 0.7790842</span>
<span class="r-out co"><span class="r-pr">#&gt;</span> 3                mpg      4 - 6 27  2.3955766 0.02379338 2.147244 1.3553509</span>
<span class="r-out co"><span class="r-pr">#&gt;</span>   CI_upper</span>
<span class="r-out co"><span class="r-pr">#&gt;</span> 1 4.516160</span>
<span class="r-out co"><span class="r-pr">#&gt;</span> 2 1.983830</span>
<span class="r-out co"><span class="r-pr">#&gt;</span> 3 3.095627</span>
<span class="r-in"><span><span class="co"># }</span></span></span>
</code></pre></div>
    </div>
  </main><aside class="col-md-3"><nav id="toc"><h2>On this page</h2>
    </nav></aside></div>


    <footer><div class="pkgdown-footer-left">
  <p></p><p>Developed by <a href="https://remi-theriault.com" class="external-link">RÃ©mi ThÃ©riault</a>.</p>
</div>

<div class="pkgdown-footer-right">
  <p></p><p>Site built with <a href="https://pkgdown.r-lib.org/" class="external-link">pkgdown</a> 2.0.7.9000.</p>
</div>

    </footer></div>

  

  

  </body></html>

