我对保留对数采样图的一侧很感兴趣,所以我想出了这个:(下采样是我的第一次尝试)
def downsample(x, y, target_length=1000, preserve_ends=0):
assert len(x.shape) == 1
assert len(y.shape) == 1
data = np.vstack((x, y))
if preserve_ends > 0:
l, data, r = np.split(data, (preserve_ends, -preserve_ends), axis=1)
interval = int(data.shape[1] / target_length) + 1
data = data[:, ::interval]
if preserve_ends > 0:
data = np.concatenate([l, data, r], axis=1)
return data[0, :], data[1, :]
def geom_ind(stop, num=50):
geo_num = num
ind = np.geomspace(1, stop, dtype=int, num=geo_num)
while len(set(ind)) < num - 1:
geo_num += 1
ind = np.geomspace(1, stop, dtype=int, num=geo_num)
return np.sort(list(set(ind) | {0}))
def log_downsample(x, y, target_length=1000, flip=False):
assert len(x.shape) == 1
assert len(y.shape) == 1
data = np.vstack((x, y))
if flip:
data = np.fliplr(data)
data = data[:, geom_ind(data.shape[1], num=target_length)]
if flip:
data = np.fliplr(data)
return data[0, :], data[1, :]
这使我能够更好地保留情节的一侧:
newx, newy = downsample(x, y, target_length=1000, preserve_ends=50)
newlogx, newlogy = log_downsample(x, y, target_length=1000)
f = plt.figure()
plt.gca().set_yscale("log")
plt.step(x, y, label="original")
plt.step(newx, newy, label="downsample")
plt.step(newlogx, newlogy, label="log_downsample")
plt.legend()
