Fix THC exponential to not sample infinity

SimpleJian · Oct 3, 2017 · 82bc97e · 82bc97e
1 parent 437d3af
commit 82bc97e
Showing 1 changed file with 3 additions and 3 deletions.
diff --git a/torch/lib/THC/THCTensorRandom.cu b/torch/lib/THC/THCTensorRandom.cu
@@ -136,16 +136,16 @@ GENERATE_KERNEL2(generate_uniform, double, double a, double b, double, curand_un
 GENERATE_KERNEL2(generate_normal, float, double mean, double stdv, float, curand_normal, (x * stdv) + mean)
 GENERATE_KERNEL2(generate_normal, double, double mean, double stdv, double, curand_normal_double, (x * stdv) + mean)
 
-GENERATE_KERNEL1(generate_exponential, float, double lambda, float, curand_uniform, (float)(-1. / lambda * log(1-x)))
-GENERATE_KERNEL1(generate_exponential, double, double lambda, double, curand_uniform_double, (double)(-1. / lambda * log(1-x)))
+GENERATE_KERNEL1(generate_exponential, float, double lambda, float, curand_uniform, (float)(-1. / lambda * log(x)))
+GENERATE_KERNEL1(generate_exponential, double, double lambda, double, curand_uniform_double, (double)(-1. / lambda * log(x)))
 
 GENERATE_KERNEL2(generate_cauchy, float, double median, double sigma, float, curand_uniform, (float)(median + sigma * tan(M_PI*(x-0.5))))
 GENERATE_KERNEL2(generate_cauchy, double, double median, double sigma, double, curand_uniform_double, (double)(median + sigma * tan(M_PI*(x-0.5))))
 
 #ifdef CUDA_HALF_TENSOR
 GENERATE_KERNEL2(generate_uniform, half, double a, double b, float, curand_uniform, (ScalarConvert<float, half>::to(x * (b-a) + a)))
 GENERATE_KERNEL2(generate_normal, half, double mean, double stdv, float, curand_normal, (ScalarConvert<float, half>::to((x * stdv) + mean)))
-GENERATE_KERNEL1(generate_exponential, half, double lambda, float, curand_uniform, (ScalarConvert<float, half>::to((float)(-1. / lambda * log(1-x)))))
+GENERATE_KERNEL1(generate_exponential, half, double lambda, float, curand_uniform, (ScalarConvert<float, half>::to((float)(-1. / lambda * log(x)))))
 GENERATE_KERNEL2(generate_cauchy, half, double median, double sigma, float, curand_uniform, (ScalarConvert<float, half>::to((float)(median + sigma * tan(M_PI*(x-0.5))))))
 #endif // CUDA_HALF_TENSOR