Corrections to exprand opcode

Author: jpffitch

opcodes/exprand.xml

@@ -32,15 +32,17 @@
   <refsect1>
     <title>Performance</title>
     <para>
-      <emphasis>klambda</emphasis> -- lambda parameter for the exponential distribution.
+      <emphasis>klambda</emphasis> -- reciprocal oflambda parameter for the exponential distribution.
     </para>
 
     <para>
-      The probablity density function of an exponential distribution is an exponential curve, whose mean is 0.69515/lambda.
+      The probablity density function of an exponential distribution
+      is an exponential curve, whose median is log(2)/lambda.
       For more detailed explanation of these distributions, see:
       <orderedlist>
         <listitem>
-          <para>C. Dodge - T.A. Jerse 1985. Computer music. Schirmer books. pp.265 - 286</para>
+          <para>C. Dodge - T.A. Jerse 1985. Computer music. Schirmer
+          books. Second edition, section 11.1B4</para>
         </listitem>
 
         <listitem>