Code snippet collection

main.md

코드 예시 모음

Javascript coroutine (non-blocking)

async function main(){
  const c = () => new Promise(res => {
    console.log("자식 코루틴");
    res();
  });
  console.log("부모 코루틴");
  await c();

  return 0;
}
main()

Rust thread (non-blocking)

use std::thread;

fn main() {
    let t = thread::spawn(move || {
        println!("자식 쓰레드");
    });
    println!("부모 쓰레드");
    t.join();
}

Tensorflow single-GPU & multi-GPU matrix multiplication

Python 3.7
TensorFlow 1.13
Numpy 1.16

TensorFlow 1.13버전 쓰려면 위 3가지 세팅 (파이썬, 넘파이 버전) 이 정확히 맞아야 함

import numpy as np
import datetime
import os
os.environ['CUDA_VISIBLE_DEVICES'] = '0,1'
#os.environ['TF_CPP_MIN_LOG_LEVEL'] = '3'

import tensorflow as tf


def singleGPU(A, B, n: int):
    print("Single GPU")
    with tf.device('/gpu:0'):
        a = tf.identity(A)
        b = tf.identity(B)
        for _ in range(n):
            a = tf.matmul(a, a)
            b = tf.matmul(b, b)

    with tf.device('/cpu:0'):
        sum = tf.add(a, b)

    t_start = datetime.datetime.now()
    with tf.Session() as sess:
        sess.run(sum)
    t_end = datetime.datetime.now()

    print(t_end - t_start)


def multiGPU(A, B, n: int):
    print("multi GPU")
    with tf.device('/gpu:0'):
        a = tf.identity(A)
        for _ in range(n):
            a = tf.matmul(a, a)

    with tf.device('/gpu:1'):
        b = tf.identity(B)
        for _ in range(n):
            b = tf.matmul(b, b)

    with tf.device('/cpu:0'):
        sum = tf.add(a, b)

    t_start = datetime.datetime.now()
    with tf.Session() as sess:
        sess.run(sum)
    t_end = datetime.datetime.now()

    print(t_end - t_start)


def main():
    with tf.device('/cpu:0'):
        A = tf.random.uniform((1 << 14, 1 << 14), dtype=tf.float32)
        B = tf.random.uniform((1 << 14, 1 << 14), dtype=tf.float32)

    n = 10

    print("A: {}, B: {}".format(A.shape, B.shape))

    singleGPU(A, B, n)
    multiGPU(A, B, n)


main()

sequential data 1-d convolution으로 학습하는 예제
sequential data가 scalar가 들어오는게 아니고 vector값이 들어오면 MyModel 에서 in_channel` 을 vector dimension 만큼 늘려주면 끝.

입력 데이터 넣기 전에 -1~1 사이로 값을 정규화 하면 성능이 훨씬 향상될 것.

import torch


class MyModel(torch.nn.Module):
    def __init__(self, time_length, kernel_size):
        super(MyModel, self).__init__()
        self.time_length = time_length
        self.conv = torch.nn.Conv1d(
            in_channels=1, out_channels=32, kernel_size=kernel_size)
        self.fc = torch.nn.Conv1d(
            in_channels=32, out_channels=1, kernel_size=1)
        self.relu = torch.nn.ReLU()

    def forward(self, x):
        h = self.relu(self.conv(x[:, :, :self.time_length - 1]))

        y_hat = self.fc(h)
        return y_hat


def main_():
    batch_size = 100
    time_length = 32
    kernel_size = 16
    total_epoch = 350

    x = torch.Tensor([[range(x, x + time_length)] for x in range(batch_size)])
    y = x[:, :, kernel_size:]

    cut = int(0.8 * batch_size)

    x_train, y_train = x[:cut], y[:cut]
    x_test, y_test = x[cut:], y[cut:]

    model = MyModel(time_length=time_length, kernel_size=kernel_size)

    loss_fn = torch.nn.L1Loss()
    optimizer = torch.optim.SGD(model.parameters(), lr=1e-4)

    for epoch in range(350):
        # train
        y_train_hat = model(x_train)
        loss_train = loss_fn(y_train_hat, y_train)

        optimizer.zero_grad()
        loss_train.backward()
        optimizer.step()

        # test
        y_test_hat = model(x_test)
        loss_test = loss_fn(y_test_hat, y_test)

        if epoch % 25 == 0 or total_epoch == 25 - 1:
            print("epoch {:4d}, train loss: {:.3f}, test loss: {:.3f}".format(
                epoch, loss_train.item(), loss_test.item()))