Updated READMEtreeFastCache.md

Author: miranov25

UTILS/Parsers/READMEtreeFastCache.md

@@ -1,7 +1,3 @@
-Here's a combined `README.md` that covers both `treeFastCache1D.C` and `treeFastCacheND.C`. It provides an overview of both systems, explains their purpose and usage, and includes examples for each.
-
----
-
 # 📦 ROOT Tree Fast Cache System
 
 This repository contains ROOT macros for fast lookup and interpolation of values from TTrees, using:
@@ -35,17 +31,17 @@ tree->Draw("dcar_value:dcar_smooth", "indexType==1", "colz", 10000);
 
 ---
 
-## 🔷 `treeFastCacheND.C`
+## 🔸 `treeFastCacheND.C`
 
 ### ✅ Features
 
 - ND caching with:
-    - **Exact match** in N–1 dimensions
-    - **Nearest-neighbor** lookup in 1 dimension (e.g. `time`)
+  - **Exact match** in N–1 dimensions
+  - **Nearest-neighbor** lookup in 1 dimension (e.g. `time`)
 - Uses full `double` precision for all keys
 - Alias support for `TTree::Draw`
 - Registration by name with hashed map ID
-- Easy to integrate, extendable to class-based interface
+- Variadic interface for direct use
 
 ### 🧪 Example: Time Series
 
@@ -57,9 +53,37 @@ setNearestNDAlias(tree, "dcar_smooth", "dcar_vs_time", "time", {"subentry"});
 tree->Draw("mTSITSTPC.mDCAr_A_NTracks_median:dcar_smooth", "indexType==1", "colz", 10000);
 ```
 
+### 🖊️ Parameters for `registerMapND`
+```cpp
+int registerMapND(
+  const std::string& name,       // Unique name of the map
+  TTree* tree,                   // Source TTree
+  const std::vector<std::string>& exactDims, // Exact-match coordinate names
+  const std::string& nearestDim,             // Nearest-match dimension (e.g. time)
+  const std::string& valueVar,               // Variable to interpolate
+  const std::string& selection               // TTree selection
+);
+```
+
+### 🖊️ Parameters for `setNearestNDAlias`
+```cpp
+void setNearestNDAlias(
+  TTree* tree,                          // Target tree
+  const std::string& aliasName,        // Alias to create
+  const std::string& mapName,          // Name used in registration
+  const std::string& nearestCoordExpr, // Nearest-match expression
+  const std::vector<std::string>& exactCoordExprs // Exact match expressions
+);
+```
+
+### ⚡️ Alternative: Direct expression
+```cpp
+tree->Draw("val:getNearestND(time,mapID,subentry)", ...);
+```
+
 ---
 
-## 🧱 Internal Storage
+## 📊 Internal Storage
 
 ### 1D:
 ```cpp
@@ -77,26 +101,26 @@ std::map<std::string, int> ndNameToID;
 
 ## 📌 Best Practices
 
-- Use aliases to simplify and standardize plotting
-- Pre-register frequently used maps in init scripts
-- Use full double precision for input axes to ensure match stability
-- Prefer descriptive names for map registration
+- Use aliases to simplify `TTree::Draw` expressions
+- Use double precision for stability in nearest search
+- Store maps by string name to simplify re-registration
+- Prefer `setNearestNDAlias()` over manual `getNearestND(...)` for readability
 
 ---
 
 ## 📤 Future Ideas
 
-- Optional linear interpolation (vs. nearest)
-- Fallback behavior when no exact match is found
-- Statistics and diagnostics on caches
-- Class-based C++ wrapper with lifecycle management
+- Optional interpolation (linear, spline)
+- Graceful handling of unmatched keys
+- Caching diagnostics and summary statistics
+- C++ class wrapper for lifecycle + reusability
 
 ---
 
-## 📄 License
+## 📜 License
 
 Intended for use in internal physics analyses. No warranty implied.
 
 ---
 
-Let me know if you'd like me to create a markdown file or commit it alongside the `.C` macros.
+For more details, see comments and examples inside `treeFastCache1D.C` and `treeFastCacheND.C`.

UTILS/Parsers/treeFastCacheND.C

@@ -163,7 +163,7 @@ void setNearestNDAlias(TTree* tree, const std::string& aliasName, const std::str
   tree->SetAlias(aliasName.c_str(), expr.c_str());
 }
 
-/// Example usage for ND map creation
+/// Example usage for ND map creation - for very High voltage queries for distertion calibration
 void exampleND() {
   TTree* tree = new TTree("tree", "demo");
   int mapID = registerMapND("test_map", tree, {"CRU", "iTF"}, "time", "val", "subentry==127");