diff --git a/regtest/analysis/rt0/Makefile b/regtest/analysis/rt0/Makefile
new file mode 100644
index 0000000000000000000000000000000000000000..3703b27cea227aa053fb6d1d73f861e4384dbcee
--- /dev/null
+++ b/regtest/analysis/rt0/Makefile
@@ -0,0 +1 @@
+include ../../scripts/test.make
diff --git a/regtest/analysis/rt0/config b/regtest/analysis/rt0/config
new file mode 100644
index 0000000000000000000000000000000000000000..f93ec1a97465724691bf162d4735f5ea3648bbb4
--- /dev/null
+++ b/regtest/analysis/rt0/config
@@ -0,0 +1,3 @@
+type=driver
+# this is to test a different name
+arg="--plumed plumed.dat --ixyz trajectory.xyz"
diff --git a/regtest/analysis/rt0/histoA.reference b/regtest/analysis/rt0/histoA.reference
new file mode 100644
index 0000000000000000000000000000000000000000..11425019a9f1aa584941f61388daf5301c3fbaac
--- /dev/null
+++ b/regtest/analysis/rt0/histoA.reference
@@ -0,0 +1,106 @@
+#! FIELDS x probs
+#! SET min_x 0.0
+#! SET max_x 3.0
+#! SET nbins_x 101
+#! SET periodic_x false
+ 0.0000 0.0000
+ 0.0300 0.0000
+ 0.0600 0.0000
+ 0.0900 0.0000
+ 0.1200 0.0000
+ 0.1500 0.0000
+ 0.1800 0.0000
+ 0.2100 0.0000
+ 0.2400 0.0000
+ 0.2700 0.0000
+ 0.3000 0.0000
+ 0.3300 0.0000
+ 0.3600 0.0000
+ 0.3900 0.0000
+ 0.4200 0.0000
+ 0.4500 0.0000
+ 0.4800 0.0000
+ 0.5100 0.0000
+ 0.5400 0.0000
+ 0.5700 0.0000
+ 0.6000 0.0000
+ 0.6300 0.0000
+ 0.6600 0.0000
+ 0.6900 0.0000
+ 0.7200 0.0000
+ 0.7500 0.0000
+ 0.7800 0.0000
+ 0.8100 0.0000
+ 0.8400 0.0000
+ 0.8700 0.0000
+ 0.9000 0.0000
+ 0.9300 0.0000
+ 0.9600 0.0000
+ 0.9900 0.0000
+ 1.0200 0.0000
+ 1.0500 0.0000
+ 1.0800 0.0000
+ 1.1100 0.0000
+ 1.1400 0.0031
+ 1.1700 0.0086
+ 1.2000 0.0221
+ 1.2300 0.0521
+ 1.2600 0.1119
+ 1.2900 0.2199
+ 1.3200 0.3947
+ 1.3500 0.6476
+ 1.3800 0.9709
+ 1.4100 1.3304
+ 1.4400 1.6661
+ 1.4700 1.9069
+ 1.5000 1.9947
+ 1.5300 1.9069
+ 1.5600 1.6661
+ 1.5900 1.3304
+ 1.6200 0.9724
+ 1.6500 0.6520
+ 1.6800 0.4067
+ 1.7100 0.2497
+ 1.7400 0.1799
+ 1.7700 0.1937
+ 1.8000 0.2921
+ 1.8300 0.4788
+ 1.8600 0.7517
+ 1.8900 1.0893
+ 1.9200 1.4485
+ 1.9500 1.7603
+ 1.9800 1.9552
+ 2.0100 1.9848
+ 2.0400 1.8414
+ 2.0700 1.5613
+ 2.1000 1.2099
+ 2.1300 0.8568
+ 2.1600 0.5546
+ 2.1900 0.3281
+ 2.2200 0.1774
+ 2.2500 0.0876
+ 2.2800 0.0396
+ 2.3100 0.0163
+ 2.3400 0.0062
+ 2.3700 0.0000
+ 2.4000 0.0000
+ 2.4300 0.0000
+ 2.4600 0.0000
+ 2.4900 0.0000
+ 2.5200 0.0000
+ 2.5500 0.0000
+ 2.5800 0.0000
+ 2.6100 0.0000
+ 2.6400 0.0000
+ 2.6700 0.0000
+ 2.7000 0.0000
+ 2.7300 0.0000
+ 2.7600 0.0000
+ 2.7900 0.0000
+ 2.8200 0.0000
+ 2.8500 0.0000
+ 2.8800 0.0000
+ 2.9100 0.0000
+ 2.9400 0.0000
+ 2.9700 0.0000
+ 3.0000 0.0000
diff --git a/regtest/analysis/rt0/histoB.reference b/regtest/analysis/rt0/histoB.reference
new file mode 100644
index 0000000000000000000000000000000000000000..0facce1f608dbfad4d6f637ce120bf88ab7d1794
--- /dev/null
+++ b/regtest/analysis/rt0/histoB.reference
@@ -0,0 +1,106 @@
+#! FIELDS x probs
+#! SET min_x 0.0
+#! SET max_x 3.0
+#! SET nbins_x 101
+#! SET periodic_x false
+ 0.0000 0.0000
+ 0.0300 0.0000
+ 0.0600 0.0000
+ 0.0900 0.0000
+ 0.1200 0.0000
+ 0.1500 0.0000
+ 0.1800 0.0000
+ 0.2100 0.0000
+ 0.2400 0.0000
+ 0.2700 0.0000
+ 0.3000 0.0000
+ 0.3300 0.0000
+ 0.3600 0.0000
+ 0.3900 0.0000
+ 0.4200 0.0000
+ 0.4500 0.0000
+ 0.4800 0.0000
+ 0.5100 0.0000
+ 0.5400 0.0000
+ 0.5700 0.0000
+ 0.6000 0.0000
+ 0.6300 0.0000
+ 0.6600 0.0000
+ 0.6900 0.0000
+ 0.7200 0.0000
+ 0.7500 0.0000
+ 0.7800 0.0000
+ 0.8100 0.0000
+ 0.8400 0.0000
+ 0.8700 0.0000
+ 0.9000 0.0000
+ 0.9300 0.0000
+ 0.9600 0.0000
+ 0.9900 0.0000
+ 1.0200 0.0000
+ 1.0500 0.0000
+ 1.0800 0.0000
+ 1.1100 0.0000
+ 1.1400 0.0027
+ 1.1700 0.0077
+ 1.2000 0.0199
+ 1.2300 0.0469
+ 1.2600 0.1008
+ 1.2900 0.1979
+ 1.3200 0.3553
+ 1.3500 0.5829
+ 1.3800 0.8740
+ 1.4100 1.1975
+ 1.4400 1.4997
+ 1.4700 1.7165
+ 1.5000 1.7954
+ 1.5300 1.7165
+ 1.5600 1.4997
+ 1.5900 1.1975
+ 1.6200 0.8756
+ 1.6500 0.5877
+ 1.6800 0.3684
+ 1.7100 0.2307
+ 1.7400 0.1755
+ 1.7700 0.2027
+ 1.8000 0.3169
+ 1.8300 0.5250
+ 1.8600 0.8262
+ 1.8900 1.1981
+ 1.9200 1.5931
+ 1.9500 1.9362
+ 1.9800 2.1505
+ 2.0100 2.1830
+ 2.0400 2.0253
+ 2.0700 1.7172
+ 2.1000 1.3307
+ 2.1300 0.9424
+ 2.1600 0.6100
+ 2.1900 0.3609
+ 2.2200 0.1951
+ 2.2500 0.0964
+ 2.2800 0.0435
+ 2.3100 0.0180
+ 2.3400 0.0068
+ 2.3700 0.0000
+ 2.4000 0.0000
+ 2.4300 0.0000
+ 2.4600 0.0000
+ 2.4900 0.0000
+ 2.5200 0.0000
+ 2.5500 0.0000
+ 2.5800 0.0000
+ 2.6100 0.0000
+ 2.6400 0.0000
+ 2.6700 0.0000
+ 2.7000 0.0000
+ 2.7300 0.0000
+ 2.7600 0.0000
+ 2.7900 0.0000
+ 2.8200 0.0000
+ 2.8500 0.0000
+ 2.8800 0.0000
+ 2.9100 0.0000
+ 2.9400 0.0000
+ 2.9700 0.0000
+ 3.0000 0.0000
diff --git a/regtest/analysis/rt0/plumed.dat b/regtest/analysis/rt0/plumed.dat
new file mode 100755
index 0000000000000000000000000000000000000000..e7911eceaebf9144adf44cccb3d30c3a4ffa8610
--- /dev/null
+++ b/regtest/analysis/rt0/plumed.dat
@@ -0,0 +1,31 @@
+x: DISTANCE ATOMS=1,2
+
+RESTRAINT ARG=x SLOPE=1.0 AT=0.0
+
+HISTOGRAM ...
+ ARG=x
+ TEMP=300
+ GRID_MIN=0.0
+ GRID_MAX=3.0
+ GRID_BIN=100
+ BANDWIDTH=0.1
+ GRID_WFILE=histoA
+ FMT=%8.4f
+ RUN=1
+... HISTOGRAM
+
+HISTOGRAM ...
+ ARG=x
+ TEMP=300
+ GRID_MIN=0.0
+ GRID_MAX=3.0
+ GRID_BIN=100
+ BANDWIDTH=0.1
+ GRID_WFILE=histoB
+ FMT=%8.4f
+ REWEIGHT_BIAS
+ RUN=1
+... HISTOGRAM
+
+
+
diff --git a/regtest/analysis/rt0/trajectory.xyz b/regtest/analysis/rt0/trajectory.xyz
new file mode 100644
index 0000000000000000000000000000000000000000..c910ae5c6fda2241cfe5be857f9b8493db430ed3
--- /dev/null
+++ b/regtest/analysis/rt0/trajectory.xyz
@@ -0,0 +1,12 @@
+2
+0 0 0
+X 0 0 0
+X 0 0 1
+2
+0 0 0
+X 0 0 0
+X 0 0 1.5
+2
+0 0 0
+X 0 0 0
+X 0 0 2
diff --git a/src/analysis/Analysis.cpp b/src/analysis/Analysis.cpp
index 08205d7fdaae8686409920971f5437786fcadcea..45483eadc847512ec597ca1e07b5e86c59d26fd9 100644
--- a/src/analysis/Analysis.cpp
+++ b/src/analysis/Analysis.cpp
@@ -222,9 +222,9 @@ void Analysis::calculate(){
double energy=plumed.getAtoms().getEnergy()+bias;
// Reweighting because of temperature difference
ww=-( (1.0/rtemp) - (1.0/simtemp) )*(energy+bias) / plumed.getAtoms().getKBoltzmann();
- // Reweighting because of biases
- if( !biases.empty() ) ww += bias/( plumed.getAtoms().getKBoltzmann()*simtemp );
}
+ // Reweighting because of biases
+ if( !biases.empty() ) ww += bias/( plumed.getAtoms().getKBoltzmann()*simtemp );
if(single_run){
// Get the arguments and store them in a vector of vectors