diff --git a/nn.c b/nn.c
index 2476c06..d9de54a 100644
--- a/nn.c
+++ b/nn.c
@@ -894,16 +894,24 @@ void AnnTestError(struct Ann *net, float *input, float *desired, int setlen, flo
 }
 
 /* Train the net */
-float AnnTrain(struct Ann *net, float *input, float *desired, float maxerr, int maxepochs, int setlen, int algo) {
+float AnnTrainWithAlgoFunc(struct Ann *net, float *input, float *desired, float maxerr,
+					int maxepochs, int setlen, AnnTrainAlgoFunc algo_func) {
     int i = 0;
     float e = maxerr+1;
 
     while (i++ < maxepochs && e >= maxerr) {
-        if (algo == NN_ALGO_BPROP) {
-            e = AnnResilientBPEpoch(net, input, desired, setlen);
-        } else if (algo == NN_ALGO_GD) {
-            e = AnnGDEpoch(net, input, desired, setlen);
-        }
+	e = (*algo_func)(net, input, desired, setlen);
     }
     return e;
 }
+	
+
+float AnnTrain(struct Ann *net, float *input, float *desired, float maxerr, int maxepochs,
+										int setlen, int algo) {
+    AnnTrainAlgoFunc algo_func;
+    if(algo == NN_ALGO_BPROP) algo_func = AnnResilientBPEpoch;
+    else if(algo == NN_ALGO_GD) algo_func = AnnGDEpoch;
+    else return -1;
+
+    return AnnTrainWithAlgoFunc(net, input, desired, maxerr, maxepochs, setlen, algo_func);
+}
diff --git a/nn.h b/nn.h
index 8106daf..db692ec 100644
--- a/nn.h
+++ b/nn.h
@@ -37,7 +37,6 @@
  * an arbitrary number of layers, with arbitrary units for layer.
  * Only fully connected feed-forward networks are supported. */
 struct AnnLayer {
-	int units;
 	float *output;		/* output[i], output of i-th unit */
 	float *error;		/* error[i], output error of i-th unit*/
 	float *weight;		/* weight[(i*units)+j] */
@@ -49,6 +48,7 @@ struct AnnLayer {
 				/* (t-1 sgradient for resilient BP) */
 	float *delta;		/* delta[(i*units)+j] cumulative update */
 				/* (per-weight delta for RPROP) */
+	int units;	/*moved to last position for alignment purposes*/
 };
 
 /* Feed forward network structure */
@@ -60,9 +60,12 @@ struct Ann {
 	float rprop_maxupdate;
 	float rprop_minupdate;
         float learn_rate; /* Used for GD training. */
+	float _filler_; /*filler for alignment*/
 	struct AnnLayer *layer;
 };
 
+typedef float (*AnnTrainAlgoFunc)(struct Ann *net, float *input, float *desired, int setlen);
+
 /* Raw interface to data structures */
 #define OUTPUT(net,l,i) (net)->layer[l].output[i]
 #define ERROR(net,l,i) (net)->layer[l].error[i]
@@ -131,6 +134,7 @@ float AnnBatchGDEpoch(struct Ann *net, float *input, float *desidered, int setle
 float AnnBatchGDMEpoch(struct Ann *net, float *input, float *desidered, int setlen);
 void AnnAdjustWeightsResilientBP(struct Ann *net);
 float AnnResilientBPEpoch(struct Ann *net, float *input, float *desidered, int setlen);
+float AnnTrainWithAlgoFunc(struct Ann *net, float *input, float *desidered, float maxerr, int maxepochs, int setlen, AnnTrainAlgoFunc algo_func);
 float AnnTrain(struct Ann *net, float *input, float *desidered, float maxerr, int maxepochs, int setlen, int algo);
 void AnnTestError(struct Ann *net, float *input, float *desired, int setlen, float *avgerr, float *classerr);
 
diff --git a/tests/Makefile b/tests/Makefile
index 574c80f..0584996 100644
--- a/tests/Makefile
+++ b/tests/Makefile
@@ -1,13 +1,13 @@
 all: nn-test-1 nn-test-2 nn-benchmark
 
 nn-test-1: nn-test-1.c ../nn.c ../nn.h
-	$(CC) nn-test-1.c ../nn.c -Wall -W -O2 -o nn-test-1
+	$(CC) nn-test-1.c ../nn.c -Wall -W -O2 -o nn-test-1 -lm
 
 nn-test-2: nn-test-2.c ../nn.c ../nn.h
-	$(CC) nn-test-2.c ../nn.c -Wall -W -O2 -o nn-test-2
+	$(CC) nn-test-2.c ../nn.c -Wall -W -O2 -o nn-test-2 -lm
 
 nn-benchmark: nn-benchmark.c ../nn.c ../nn.h
-	$(CC) -DUSE_SSE nn-benchmark.c ../nn.c -Wall -W -O3 -o nn-benchmark
+	$(CC) -DUSE_SSE nn-benchmark.c ../nn.c -Wall -W -O3 -o nn-benchmark -lm
 
 clean:
 	rm -f nn-test-1 nn-test-2 nn-benchmark