Merge pull request #368 from fjclark/feature-improved-mbar-errors

Improve error messages if no lambda windows found during analysis

python/BioSimSpace/FreeEnergy/_relative.py

@@ -1435,6 +1435,12 @@ def _analyse_amber(work_dir=None, estimator="MBAR", method="alchemlyb", **kwargs
             for part in file.parts:
                 if "lambda" in part:
                     lambdas.append(float(part.split("_")[-1]))
+        if len(lambdas) == 0:
+            raise ValueError(
+                "No lambda windows were detected from the output directory names! "
+                "Ensure that the directory being analysed contains sub-directories"
+                "name e.g `lambda_0`, `lambda_1` containing the output files."
+            )
 
         # Find the temperature for each lambda window.
         temperatures = []
@@ -1516,6 +1522,12 @@ def _analyse_gromacs(work_dir=None, estimator="MBAR", method="alchemlyb", **kwar
                 for part in file.parts:
                     if "lambda" in part:
                         lambdas.append(float(part.split("_")[-1]))
+        if len(lambdas) == 0:
+            raise ValueError(
+                "No lambda windows were detected from the output directory names! "
+                "Ensure that the directory being analysed contains sub-directories"
+                "name e.g `lambda_0`, `lambda_1` containing the output files."
+            )
 
             # Find the temperature at each lambda window
             temperatures = []
@@ -1685,6 +1697,12 @@ def _analyse_somd(work_dir=None, estimator="MBAR", method="alchemlyb", **kwargs)
                 for part in file.parts:
                     if "lambda" in part:
                         lambdas.append(float(part.split("_")[-1]))
+        if len(lambdas) == 0:
+            raise ValueError(
+                "No lambda windows were detected from the output directory names! "
+                "Ensure that the directory being analysed contains sub-directories"
+                "name e.g `lambda_0`, `lambda_1` containing the output files."
+            )
 
             temperatures = []
             for file in files: