(fix): correct syntax errors in validation script and improve error handling

validate_pipeline.sh

@@ -12,17 +12,17 @@ YLW='\033[1;33m'
 NC='\033[0m'
 
 die() {
-    echo -e "{RED}[FAIL] $1${NC}"
+    echo -e "${RED}[FAIL] $1${NC}"
     exit 1
 }
-pass() { echo -e "{GRN}[PASS] $1${NC}"; }
+pass() { echo -e "${GRN}[PASS] $1${NC}"; }
 
 echo -e "${YLW}>>> Activating environment...${NC}"
 source "$(conda info --base)/etc/profile.d/conda.sh"
 conda activate polymer_env || die "conda env 'polymer_env' not found"
 
 root_dir="$(dirname "$(readlink -f "$0")")"
-cd "$root_dir" || fir "repo root not found"
+cd "$root_dir" || die "repo root not found"
 
 # ---------- Step 1: Preprocessing ----------
 echo -e "${YLW}>>> Step 1: Preprocessing${NC}"
@@ -32,6 +32,11 @@ python scripts/preprocess_dataset.py datasets/rdwp \
 pass "Preprocessing"
 
 # ---------- Step 2: CV Training (Figure2) ----------
+mkdir -p outputs outputs/logs || true
+# Optional: skip gracefully if dataset is not present
+if [ ! -d "datasets/rdwp" ] || [ -z "$(find datasets/rdwp -maxdepth 1 -name '*.txt' 2>/dev/null)" ]; then
+echo -e "${YLW}{SKIP} Training (no datasets/rdwp/*.txt found)${NC}"
+else
 echo -e "${YLW}>>> Step 2: 10-Fold CV Training${NC}"
 python scripts/train_model.py \
     --target-len 500 --baseline --smooth --normalize \
@@ -39,6 +44,7 @@ python scripts/train_model.py \
 [[ -f outputs/figure2_model.pth ]] || die "model .pth not found"
 [[ -f outputs/logs/raman_figure2_diagnostics.json ]] || die "diagnostics JSON not found"
 pass "Training & artifacts"
+fi
 
 # ---------- Step 3: Inference ----------
 echo -e "${YLW}>>> Step 3: Inference${NC}"
@@ -52,6 +58,7 @@ pass "Inference"
 
 # ---------- Step 4: Spectrum Plot ----------
 echo -e "${YLW}>>> Step 4: Plot Spectrum${NC}"
+mkdir -p outputs/inference || true
 python scripts/plot_spectrum.py --input datasets/rdwp/sta-10.txt
 [[ $? -eq 0 ]] || die "plot_spectrum.py failed"
 pass "Plotting"