Web1、说在前面 最近在学习object detection的论文,又遇到交叉熵、高斯混合模型等之类的知识,发现自己没有搞明白这些概念,也从来没有认真总结归纳过,所以觉得自己应该沉下心,对以前的知识做一个回顾与总结,特此先简单倒腾了一下博客,使之美观一些,再进行总结。 Web计算公式: 交叉熵描述了两个概率分布之间的距离,当交叉熵越小说明二者之间越接近。 公式设计的目的: 对于positive样本 y=1,loss= - logy^ , 当y^ 越大时,loss越小。最理想情况下y^=1,loss=0. 对于negative样本 y=0,loss= - log(1-y^), 当y^ 越小时,loss越小。
关于交叉熵损失函数Cross Entropy Loss - 代码天地
If you look this loss functionup, this is what you’ll find: where y is the label (1 for green points and 0 for red points) and p(y) is the predicted probability of the point being green for all Npoints. Reading this formula, it tells you that, for each green point (y=1), it adds log(p(y)) to the loss, that is, the log probability of it … See more If you are training a binary classifier, chances are you are using binary cross-entropy / log lossas your loss function. Have you ever … See more I was looking for a blog post that would explain the concepts behind binary cross-entropy / log loss in a visually clear and concise manner, so I … See more First, let’s split the points according to their classes, positive or negative, like the figure below: Now, let’s train a Logistic Regression to … See more Let’s start with 10 random points: x = [-2.2, -1.4, -0.8, 0.2, 0.4, 0.8, 1.2, 2.2, 2.9, 4.6] This is our only feature: x. Now, let’s assign some colors … See more WebApr 16, 2024 · 在自己实现F.binary_cross_entropy之前,我们首先得看一下pytorch的官方实现,下面是pytorch官方对BCELoss类的描述: 在目标和输出之间创建一个衡量二进制交 … grant access on schema snowflake
Cross entropy - Wikipedia
WebJul 2, 2024 · tf.keras.losses下面有两个长得非常相似的损失函数,binary_crossentropy(官网传送门)与BinaryCrossentropy(官网传送门)。从官网介绍来看,博主也没看出这两个 … Webbinary_cross_entropy: 这个损失函数非常经典,我的第一个项目实验就使用的它。 在这里插入图片描述 在上述公式中,xi代表第i个样本的真实概率分布,yi是模型预测的概率分 … Webnn.ConvTranspose3d. Applies a 3D transposed convolution operator over an input image composed of several input planes. nn.LazyConv1d. A torch.nn.Conv1d module with lazy initialization of the in_channels argument of the Conv1d that is inferred from the input.size (1). nn.LazyConv2d. chin\u0027s th