File size: 5,747 Bytes
c082aa2
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
#!/usr/bin/env python3
"""
Test different model sizes on expression generation.
Compare GPT-2 (124M), GPT-2-medium (355M), GPT-2-large (774M).
"""

import os
import sys
import json
import argparse
from pathlib import Path

import numpy as np
import torch

# Add project root to path
PROJECT_ROOT = Path(__file__).parent.parent
sys.path.insert(0, str(PROJECT_ROOT))
sys.path.insert(0, str(PROJECT_ROOT / "classes"))

from transformers import AutoTokenizer, AutoModelForCausalLM
from expression import Expression


def generate_expressions(model_name: str, num_samples: int = 20, device: str = None):
    """Generate expressions with a given model."""

    if device is None:
        device = torch.device("cuda" if torch.cuda.is_available() else "cpu")
    else:
        device = torch.device(device)

    print(f"Loading {model_name}...")
    tokenizer = AutoTokenizer.from_pretrained(model_name)
    tokenizer.pad_token = tokenizer.eos_token

    model = AutoModelForCausalLM.from_pretrained(model_name)
    model = model.to(device)
    model.eval()

    # Build prompt (JSON format)
    vars_list = ["x_1"]
    ops_list = ["+", "-", "*", "/", "sin", "cos", "sqrt", "log", "exp", "pow"]
    prompt = json.dumps({"vars": vars_list, "ops": ops_list, "cons": "C", "expr": ""})[:-2]

    expressions = []
    valid_count = 0
    has_power = 0
    has_nested_trig = 0
    depths = []

    print(f"Generating {num_samples} expressions...")

    for i in range(num_samples):
        inputs = tokenizer(prompt, return_tensors="pt").to(device)

        with torch.no_grad():
            outputs = model.generate(
                **inputs,
                max_new_tokens=50,
                temperature=0.7,
                do_sample=True,
                pad_token_id=tokenizer.eos_token_id,
            )

        text = tokenizer.decode(outputs[0], skip_special_tokens=True)

        # Extract expression
        expr_str = ""
        if '"expr": "' in text:
            start = text.index('"expr": "') + len('"expr": "')
            remaining = text[start:]
            for terminator in ['"}', '"']:
                if terminator in remaining:
                    expr_str = remaining[:remaining.index(terminator)].strip()
                    break

        if not expr_str:
            continue

        # Validate
        test_expr = expr_str.replace('C', '1')
        is_valid = False

        try:
            expr = Expression(test_expr, is_prefix=False)
            # Simple validation - just check if it parses
            is_valid = True
        except:
            pass

        # Count features
        if is_valid:
            valid_count += 1

            if '**' in expr_str or 'pow(' in expr_str:
                has_power += 1

            if any(nested in expr_str for nested in ['sin(sin', 'sin(cos', 'cos(sin', 'cos(cos']):
                has_nested_trig += 1

            depth = max(expr_str.count('('), 1)
            depths.append(depth)

        expressions.append({
            "expression": expr_str,
            "is_valid": is_valid,
        })

    # Stats
    stats = {
        "model_name": model_name,
        "total": len(expressions),
        "valid": valid_count,
        "valid_pct": 100 * valid_count / len(expressions) if expressions else 0,
        "has_power": has_power,
        "has_power_pct": 100 * has_power / valid_count if valid_count > 0 else 0,
        "has_nested_trig": has_nested_trig,
        "has_nested_trig_pct": 100 * has_nested_trig / valid_count if valid_count > 0 else 0,
        "avg_depth": sum(depths) / len(depths) if depths else 0,
        "max_depth": max(depths) if depths else 0,
    }

    return expressions, stats


def main():
    parser = argparse.ArgumentParser()
    parser.add_argument("--models", nargs="+", default=["gpt2", "gpt2-medium"],
                        help="Models to test")
    parser.add_argument("--num_samples", type=int, default=20, help="Samples per model")
    parser.add_argument("--output_file", type=str, default="model_size_comparison.json")
    args = parser.parse_args()

    results = {}

    for model_name in args.models:
        print()
        print("="*80)
        print(f"Testing {model_name}")
        print("="*80)

        expressions, stats = generate_expressions(model_name, args.num_samples)

        results[model_name] = {
            "stats": stats,
            "expressions": expressions,
        }

        print()
        print(f"Results for {model_name}:")
        print(f"  Valid: {stats['valid']}/{stats['total']} ({stats['valid_pct']:.1f}%)")
        print(f"  With power: {stats['has_power']} ({stats['has_power_pct']:.1f}%)")
        print(f"  With nested trig: {stats['has_nested_trig']} ({stats['has_nested_trig_pct']:.1f}%)")
        print(f"  Avg depth: {stats['avg_depth']:.2f}")
        print(f"  Max depth: {stats['max_depth']}")

        # Show examples
        print()
        print("Sample expressions:")
        valid_exprs = [e for e in expressions if e["is_valid"]][:5]
        for i, e in enumerate(valid_exprs, 1):
            print(f"  {i}. {e['expression'][:70]}")

    # Save
    with open(args.output_file, "w") as f:
        json.dump(results, f, indent=2)

    print()
    print(f"Saved results to {args.output_file}")

    # Comparison table
    print()
    print("="*80)
    print("COMPARISON")
    print("="*80)
    print(f"{'Model':<20} {'Valid%':>8} {'Power%':>8} {'NestedTrig%':>12} {'AvgDepth':>10}")
    print("-"*80)
    for model_name, data in results.items():
        stats = data["stats"]
        print(f"{model_name:<20} {stats['valid_pct']:>7.1f}% {stats['has_power_pct']:>7.1f}% {stats['has_nested_trig_pct']:>11.1f}% {stats['avg_depth']:>10.2f}")


if __name__ == "__main__":
    main()