[mlpack-git] master, mlpack-1.0.x: arma::sign() doesn't exist in Armadillo pre-3.920. (d35bd6c)

[gitdub at big.cc.gt.atl.ga.us]

Repository : https://github.com/mlpack/mlpack

On branches: master,mlpack-1.0.x
Link       : https://github.com/mlpack/mlpack/compare/904762495c039e345beba14c1142fd719b3bd50e...f94823c800ad6f7266995c700b1b630d5ffdcf40

>---------------------------------------------------------------

commit d35bd6c364ecce399927cec83278397eda48648b
Author: Ryan Curtin <ryan at ratml.org>
Date:   Thu Jul 3 13:55:23 2014 +0000

    arma::sign() doesn't exist in Armadillo pre-3.920.


>---------------------------------------------------------------

d35bd6c364ecce399927cec83278397eda48648b
 src/mlpack/core/dists/laplace_distribution.hpp | 15 +++++++++++++--
 1 file changed, 13 insertions(+), 2 deletions(-)

diff --git a/src/mlpack/core/dists/laplace_distribution.hpp b/src/mlpack/core/dists/laplace_distribution.hpp
index 5757f8e..63aa7f4 100644
--- a/src/mlpack/core/dists/laplace_distribution.hpp
+++ b/src/mlpack/core/dists/laplace_distribution.hpp
@@ -89,8 +89,19 @@ class LaplaceDistribution
     result.randu();
 
     // Convert from uniform distribution to Laplace distribution.
-    return mean - scale * arma::sign(result) % arma::log(1 - 2.0 * (result -
-        0.5));
+    // arma::sign() does not exist in Armadillo < 3.920 so we have to do this
+    // elementwise.
+    for (size_t i = 0; i < result.n_elem; ++i)
+    {
+      if (result[i] < 0)
+        result[i] = mean[i] + scale * result[i] * std::log(1 + 2.0 * (result[i]
+            - 0.5));
+      else
+        result[i] = mean[i] - scale * result[i] * std::log(1 - 2.0 * (result[i]
+            - 0.5));
+    }
+
+    return result;
   }
 
   /**