Python 如何在Tensorflow中实现元素一维插值?
我想对Tensorflow中张量的每个元素应用1D插值 例如,如果它是一个矩阵,我们可以使用Python 如何在Tensorflow中实现元素一维插值?,python,tensorflow,interpolation,Python,Tensorflow,Interpolation,我想对Tensorflow中张量的每个元素应用1D插值 例如,如果它是一个矩阵,我们可以使用interp1d from scipy.interpolate import interp1d q = np.array([[2, 3], [5, 6]]) # query x = [1, 3, 5, 7, 9] # profile x y = [3, 4, 5, 6, 7] # profile y fn = interp1d(x, y) # fn(
interp1d
from scipy.interpolate import interp1d
q = np.array([[2, 3], [5, 6]]) # query
x = [1, 3, 5, 7, 9] # profile x
y = [3, 4, 5, 6, 7] # profile y
fn = interp1d(x, y)
# fn(q) == [[ 3.5, 4.], [5., 5.5]]
如果我们有一个张量q
q = tf.placeholder(shape=[2,2], dtype=tf.float32)
如何进行等效元素一维插值?
有人能帮忙吗?我正在使用包装器:
import numpy as np
import tensorflow as tf
from scipy.interpolate import interp1d
x = [1, 3, 5, 7, 9]
y = [3, 4, 5, 6, 7]
intFn = interp1d(x, y)
def fn(m):
return intFn(m).astype(np.float32)
q = tf.placeholder(shape=[2,2], dtype=tf.float32)
q1 = np.array([[2, 3], [5, 6]]).astype(np.float32)
f1 = tf.py_func(fn, [q], tf.float32)
with tf.Session() as sess:
init = tf.global_variables_initializer()
sess.run(init)
result = sess.run(f1, feed_dict={q:q1})
print(result)
这不是最好的解决办法。希望tensor flow将在numpy和scipy中实现更多功能
编辑:
我写了一个简单的tensorflow函数,可能会有用。不幸的是,这是一次只能做一个值。然而,如果它是有趣的,这可能是一些可以改进的东西
def interpolate( dx_T, dy_T, x, name='interpolate' ):
with tf.variable_scope(name):
with tf.variable_scope('neighbors'):
delVals = dx_T - x
ind_1 = tf.argmax(tf.sign( delVals ))
ind_0 = ind_1 - 1
with tf.variable_scope('calculation'):
value = tf.cond( x[0] <= dx_T[0],
lambda : dy_T[:1],
lambda : tf.cond(
x[0] >= dx_T[-1],
lambda : dy_T[-1:],
lambda : (dy_T[ind_0] + \
(dy_T[ind_1] - dy_T[ind_0]) \
*(x-dx_T[ind_0])/ \
(dx_T[ind_1]-dx_T[ind_0]))
))
result = tf.multiply(value[0], 1, name='y')
return result
现在您可以这样使用它:
x = [1, 3, 5, 7, 9] # profile x
y = [3, 4, 5, 6, 7] # profile y
q = np.array([[2, 3], [5, 6]])
with tf.Session() as sess:
sess.run(init)
for i in q.flatten():
result = sess.run(y_T,
feed_dict={
'inputs/dx:0' : x,
'inputs/dy:0' : y,
'inputs/inpValue:0' : np.array([i])
})
print('{:6.3f} -> {}'.format(i, result))
您将获得期望的结果…您是否发现一些改进?
x = [1, 3, 5, 7, 9] # profile x
y = [3, 4, 5, 6, 7] # profile y
q = np.array([[2, 3], [5, 6]])
with tf.Session() as sess:
sess.run(init)
for i in q.flatten():
result = sess.run(y_T,
feed_dict={
'inputs/dx:0' : x,
'inputs/dy:0' : y,
'inputs/inpValue:0' : np.array([i])
})
print('{:6.3f} -> {}'.format(i, result))