diff --git a/parallel/para_gibbs.cu b/parallel/para_gibbs.cu
index 6361bf4..f9a1f5b 100644
--- a/parallel/para_gibbs.cu
+++ b/parallel/para_gibbs.cu
@@ -118,6 +118,11 @@ int main(int argc, char **argv){
 
   load_data(argc, argv, &K, &y, &n);
 
+  if(K<nBlocks*nThreads){
+     printf("Too many threads for too little data!!!");
+     return 1;
+  }
+
   /* starting values of hyperparameters */
   a = 20;
   b = 1;
@@ -215,7 +220,7 @@ __global__ void mergePosterior(int trials, float *dev_a_out,float *dev_b_out,int
     h[i] = powf(i,(-1/(4+2)));
     for (int m=0; m < M; m++) {
       int *cDot = (int*) malloc(M*sizeof(int));
-  printf("%d\n",m);
+  //printf("%d\n",m);
  
       memcpy(cDot, tDot, sizeof(int) * M);
       cDot[m] = (curand(&state[id]) % (trials-1)) + 1;
@@ -231,7 +236,7 @@ __global__ void mergePosterior(int trials, float *dev_a_out,float *dev_b_out,int
     float posterior_mean_a = posteriorMean(tDot, dev_a_out, M, trials);
     float posterior_mean_b = posteriorMean(tDot, dev_b_out, M, trials);
     float variance = (h[i]*h[i])/M;
-    printf("%d\n",trials);
+   // printf("%d\n",trials);
     printf("%f, %f\n" , general_normoral(state, posterior_mean_a, variance), general_normoral(state, posterior_mean_b, variance));
   }
 }
@@ -239,7 +244,9 @@ __global__ void mergePosterior(int trials, float *dev_a_out,float *dev_b_out,int
 
 __device__ float general_normoral(curandState *state, float mean, float variance) {
     int id = threadIdx.x + blockIdx.x * blockDim.x;
-    return curand_normal(&state[id]) * variance + mean;
+    float n = curand_normal(&state[id]) * variance + mean;
+   // printf("normal is:%f\n",n);
+    return n;
 }
 
 __device__ float posteriorMean(int *tDot, float *dev_x_out, int M, int nThreads) {
@@ -247,8 +254,13 @@ __device__ float posteriorMean(int *tDot, float *dev_x_out, int M, int nThreads)
   for (int i=0; i < M; i++) {
     int index =  tDot[i] + i * nThreads;  // trial m of posterior m (note: i = blockId)
     sum += dev_x_out[index];  // posterior_m_tm
+  // printf("data is %f\n",dev_x_out[index]);
+
+// printf("sum is %f\n",sum);
+
   }
   float mean = sum/M;
+ // printf("mean is %f\n",mean);
   return mean;
 }
 
@@ -269,7 +281,9 @@ __device__ float computeW(int *tDot, float *dev_x_out, float *dev_y_out, int M,
 }
 
 __device__ float normPDF(float x, float mean, float variance) {
+  
   float denominator = sqrtf(2*PI*(variance*variance));
+  //printf("the denominator is %f\n",PI);
   float numerator = expf( -1 * (x-mean)*(x-mean) / (2*variance*variance) );
   return numerator/denominator;
 }
@@ -349,6 +363,8 @@ __global__ void seqMetroProcess(int K, int nBlocks, int *y, float *n, curandStat
       float sum_logs=0;
       for(int ii=0;ii<lengthPerBlock;ii++){
          //*ptr refers to the value at address
+        // printf("sLogTheta:%f \n",*sLogTheta);
+
          sum_logs = sum_logs + *sLogTheta;
          sLogTheta++;
       }
@@ -360,7 +376,7 @@ __global__ void seqMetroProcess(int K, int nBlocks, int *y, float *n, curandStat
       b = sample_b(state,id, a, lengthPerBlock, flat_sum);
 
     /* print hyperparameters. */
-    //printf("%f, %f\n", a, b);
+   // printf("%f, %f\n", a, b);
     ////////////save new output to the global array
     *subA = a;
     subA++;
@@ -415,6 +431,7 @@ __host__ void load_data(int argc, char **argv, int *K, int **y, float **n){
  */
 
 __device__ float sample_a(curandState *state,int id, float a, float b, int K, float sum_logs){
+  //id = threadIdx.x + blockIdx.x * blockDim.x;
 
   float sigma = 2.0;
   float norm = curand_normal(&state[id]);
@@ -423,11 +440,13 @@ __device__ float sample_a(curandState *state,int id, float a, float b, int K, fl
   if(proposal <= 0)
     return a;
 
+ // printf("sum_logs:%f \n",sum_logs);
+
   log_acceptance_ratio = (proposal - a) * sum_logs +
                          K * (proposal - a) * log(b) -
                          K * (lgamma(proposal) - lgamma(a));
 
-  U = curand_normal(&state[id]);
+  U = curand_uniform(&state[id]);
   //printf("log_acceptance result:%f \n",log_acceptance_ratio);
   //printf("log U result:%f \n",log(U));
 
@@ -446,6 +465,7 @@ __device__ float sample_a(curandState *state,int id, float a, float b, int K, fl
  */
 
 __device__ float sample_b(curandState *state,int id, float a, int K, float flat_sum){
+  //id = threadIdx.x + blockIdx.x * blockDim.x;
 
   float hyperA = K * a + 1;
   float hyperB = flat_sum;