title: Saving right handside of an equation in r
body: <p>I want save the following expression in r</p>
  <pre><code> DA&lt;-   b0 + b1 * x1 + b4 * x4 + b5 * x5 + b6 * x6 + b8 * x8 +
        b9 * x9 + b10 * x10 + b11 * x11 + b12 * x12 + b13 * x13 + b15 * x15 +
        b17 * x17 + b18 * x18 + b19 * x19 + b20 * x20 + b21 * x21 + b25 * x25 + b27 * x27 + bl2 * d2 + bl3 *
        d3 + bl5 * d5 + bl6 * d6 + bl7 * d7 +  bl8 * d8 + bl9 * d9 + bl10 * d10 + bl11 * d11
  </code></pre>
  <p>Here all elements starting with a <code>b</code> are estimated coefficients and <code>x</code>is a column in the dataframe. I want <code>DA</code> to appear in the log likelihood expression as</p>
  <p><code>sum(log((pnorm(DA)^y)*((1-pnorm(DA))^(1-y))))</code></p>
  <p>Unfortunately r does not let me save <code>DA</code> and gives <code>Error: object 'b0' not found</code>, hence I cannot estimate the log likelihood function. Where am I going wrong.</p>