Bus index respect bus i

.gitignore

@@ -4,7 +4,7 @@ octave-workspace
 # Local
 tests/results/*.xlsx
 tests/results/**/*.xlsx
-
+data/*.xlsx
 
 # Playground
 playground.ipynb

CONTRIBUTING.md

@@ -30,7 +30,6 @@ Optionally, if you want to test matlab compatibility, you can install `matlabeng
 uv pip install matlabengine
 ```
 
-
 ## Install in development mode
 
 ```shell

data/case9_reduced.m

@@ -0,0 +1,41 @@
+function mpc = case9_reduced
+%CASE9_REDUCED  6-bus reduced of power flow data from 9 bus, 3 generator case.
+%   Derived from the standard CASE9 test case data from Joe H. Chow's book, p. 70.
+%   by removing the three branch without BR_R and move the generator.
+%
+%   Original Bus 1 (Gen 1) merged into Bus 4  (slack)
+%   Original Bus 2 (Gen 2) merged into Bus 8  (PV)
+%   Original Bus 3 (Gen 3) merged into Bus 6  (PV)
+
+mpc.version = '2';
+mpc.baseMVA = 100;
+
+%% bus data
+%  bus_i  type  Pd    Qd  Gs  Bs  area  Vm        Va          baseKV  zone  Vmax  Vmin
+mpc.bus = [
+    4      3     0     0   0   0   1     1.040000  -2.216788   345     1     1.1   0.9;
+    5      1     90    30  0   0   1     1.019544  -3.599309   345     1     1.1   0.9;
+    6      2     0     0   0   0   1     1.025000   2.208471   345     1     1.1   0.9;
+    7      1     100   35  0   0   1     1.012276   0.912347   345     1     1.1   0.9;
+    8      2     0     0   0   0   1     1.025000   3.885641   345     1     1.1   0.9;
+    9      1     125   50  0   0   1     1.005122  -3.900271   345     1     1.1   0.9;
+];
+
+%% generator data
+%  bus  Pg          Qg          Qmax  Qmin   Vg     mBase  status  Pmax  Pmin
+mpc.gen = [
+    4    71.730424   38.076988   300   -300   1.040  100    1       250   10;
+    8    163.000000  -11.552844  300   -300   1.025  100    1       300   10;
+    6    85.000000   -26.910102  300   -300   1.025  100    1       270   10;
+];
+
+%% branch data
+%  fbus  tbus  r       x       b       rateA  rateB  rateC  tap  shift  status  angmin  angmax
+mpc.branch = [
+    4     5     0.0170  0.0920  0.158   250    250    250    0    0      1       -360    360;
+    5     6     0.0390  0.1700  0.358   150    150    150    0    0      1       -360    360;
+    6     7     0.0119  0.1008  0.209   150    150    150    0    0      1       -360    360;
+    7     8     0.0085  0.0720  0.149   250    250    250    0    0      1       -360    360;
+    8     9     0.0320  0.1610  0.306   250    250    250    0    0      1       -360    360;
+    9     4     0.0100  0.0850  0.176   250    250    250    0    0      1       -360    360;
+];

matpowercaseframes/core.py

@@ -1023,15 +1023,48 @@ def _get_dataframe(self, attribute, data, n_cols=None, columns_template=None):
 
     def _update_index(self, allow_any_keys=False):
         """
-        Update the index of the bus, branch, and generator tables based on naming.
+        Update the index of the bus, branch, generator, etc tables based on naming.
 
+        For buses, prefer:
+        1) bus_name (if available)
+        2) BUS_I column (if available)
+        3) a 1-based RangeIndex fallback
 
         Args:
             allow_any_keys (bool):
                 Whether to update index for any keys beyond standard attributes.
         """
+
         for attribute, attribute_name in zip(["bus", "branch", "gen"], ATTRIBUTES_NAME):
             attribute_data = getattr(self, attribute)
+
+            if attribute == "bus":
+                try:
+                    attribute_name_data = getattr(self, attribute_name)  # bus_name
+                    attribute_data.set_index(
+                        attribute_name_data, drop=False, inplace=True
+                    )
+                    continue
+                except AttributeError:
+                    pass
+
+                if (
+                    isinstance(attribute_data, pd.DataFrame)
+                    and "BUS_I" in attribute_data.columns
+                ):
+                    attribute_data.set_index(
+                        attribute_data["BUS_I"].astype(int), drop=False, inplace=True
+                    )
+                    attribute_data.index.name = "bus"
+                    continue
+
+                attribute_data.set_index(
+                    pd.RangeIndex(1, len(attribute_data.index) + 1, name="bus"),
+                    drop=False,
+                    inplace=True,
+                )
+                continue
+
             try:
                 attribute_name_data = getattr(self, attribute_name)
                 attribute_data.set_index(attribute_name_data, drop=False, inplace=True)