high-performance-computing

## What I do - Optimize computational performance - Implement parallel algorithms - Use vectorization - Design GPU kernels ## When to use me When optimizing performance-critical code or implementing parallel algorithms. ## Parallelization ### Threading ```python import threading from concurrent.futures import ThreadPoolExecutor class ParallelProcessor: """Thread-based parallel processing""" def __init__(self, num_workers: int = None): self.num_workers = num_workers or threading.active_count() def parallel_map(self, func: Callable, items: List) -> List: """Map function over items in parallel""" with ThreadPoolExecutor(max_workers=self.num_workers) as executor: results = list(executor.map(func, items)) return results def parallel_reduce(self, func: Callable, items: List, num_workers: int = None) -> Any: """Parallel reduction""" chunk_size = len(items) // (num_workers or self.num_workers) chunks = [items[i:i+chunk_size] for i in range(0, len(items), chunk_size)] with ThreadPoolExecutor(max_workers=num_workers) as executor: chunk_results = list(executor.map( lambda chunk: reduce(func, chunk), chunks )) return reduce(func, chunk_results) ``` ### Multiprocessing ```python import multiprocessing as mp class ProcessPool: """Process-based parallel processing""" @staticmethod def parallelize(data: List, func: Callable, num_processes: int = None) -> List: """Distribute work across processes""" num_processes = num_processes or mp.cpu_count() with mp.Pool(num_processes) as pool: results = pool.map(func, data) return results @staticmethod def shared_memory_arrays(data: np.ndarray): """Share memory between processes""" shared = mp.Array('d', data.flatten()) return np.frombuffer(shared.get_obj()).reshape(data.shape) ``` ### GPU Computing (CUDA-style) ```python class GPUKernel: """GPU kernel patterns""" @staticmethod def vector_add(a: np.ndarray, b: np.ndarray) -> np.ndarray: """Vector addition on GPU""" # Pseudocode - use numba/cupy result = np.empty_like(a) # Each thread handles one element for i in range(len(a)): result[i] = a[i] + b[i] return result @staticmethod def matrix_multiply(a: np.ndarray, b: np.ndarray) -> np.ndarray: """Matrix multiplication with tiling""" # Blocked matrix multiplication BLOCK_SIZE = 16 result = np.zeros((a.shape[0], b.shape[1])) # Each block handled by thread block for i in range(0, a.shape[0], BLOCK_SIZE): for j in range(0, b.shape[1], BLOCK_SIZE): for k in range(0, a.shape[1], BLOCK_SIZE): # Process block i_end = min(i + BLOCK_SIZE, a.shape[0]) j_end = min(j + BLOCK_SIZE, b.shape[1]) k_end = min(k + BLOCK_SIZE, a.shape[1]) for ii in range(i, i_end): for jj in range(j, j_end): sum_val = 0 for kk in range(k, k_end): sum_val += a[ii, kk] * b[kk, jj] result[ii, jj] += sum_val return result ``` ### Vectorization ```python class VectorizedOps: """Vectorized operations""" @staticmethod def naive_loop(arr: np.ndarray) -> float: """Slow: element-by-element""" result = 0.0 for x in arr: result += x * x return result @staticmethod def vectorized(arr: np.ndarray) -> float: """Fast: vectorized""" return np.sum(arr ** 2) @staticmethod def matrix_vector_product(matrix: np.ndarray, vector: np.ndarray) -> np.ndarray: """Optimized matrix-vector product""" return matrix @ vector # Uses BLAS @staticmethod def conditional_accumulate(arr: np.ndarray) -> float: """Vectorized conditional""" # Instead of: for x in arr: if x > 0: sum += x return np.sum(arr[arr > 0]) ``` ### Memory Optimization ```python class MemoryOptimizer: """Optimize memory access patterns""" @staticmethod def cache_friendly_traversal(matrix: np.ndarray) -> np.ndarray: """Row-major traversal (cache-friendly in C)""" rows, cols = matrix.shape result = np.zeros((rows, cols)) for i in range(rows): for j in range(cols): result[i, j] = matrix[i, j] return result @staticmethod def cache_unfriendly_traversal(matrix: np.ndarray) -> np.ndarray: """Column-major (cache-unfriendly)""" rows, cols = matrix.shape result = np.zeros((rows, cols)) for j in range(cols): for i in range(rows): result[i, j] = matrix[i, j] return result @staticmethod def cache_blocking(matrix: np.ndarray, block_size: int = 64) -> np.ndarray: """Cache blocking for better performance""" rows, cols = matrix.shape result = np.zeros_like(matrix) for i in range(0, rows, block_size): for j in range(0, cols, block_size): i_end = min(i + block_size, rows) j_end = min(j + block_size, cols) result[i:i_end, j:j_end] = \ matrix[i:i_end, j:j_end] return result @staticmethod def preallocate(size: int) -> np.ndarray: """Preallocate array to avoid resizing""" return np.zeros(size) ``` ### Performance Profiling ```python class PerformanceProfiler: """Profile code performance""" @staticmethod @profile # Line-by-line profiling def profiled_function(data: np.ndarray) -> float: """Function to profile""" return np.sum(data ** 2) @staticmethod def profile_section(func: Callable) -> Callable: """Decorator to profile code sections""" def wrapper(*args, **kwargs): import cProfile import pstats profiler = cProfile.Profile() profiler.enable() result = func(*args, **kwargs) profiler.disable() stats = pstats.Stats(profiler) stats.sort_stats('cumulative') stats.print_stats(10) return result return wrapper ```