阶跃函数与线性决策
了解感知器如何划分两个类别
阶跃函数与线性决策 是 CoddyKit 上的免费 Deep Learning Academy 课时。 这是第 2 节课，共 4 节。 你可以在下方免费阅读本课时的完整内容 — 然后在浏览器中使用内置代码编辑器和全天候 AI 导师进行实践。 这是 Deep Learning Academy 学习路径的一部分，你的进度在网页和 CoddyKit 应用中同步。 Deep Learning Academy 课程共包含 4 节课。
本课时的部分内容尚未翻译，以英文显示。
From Score to Decision
The weighted sum gives a score, but you often need a clean yes or no. A step function turns that raw score into a firm decision.
What the Step Does
The step function outputs 1 if the score is at or above zero, and 0 if it is below. No in-between, just on or off. ⚡
output = 1 if score >= 0 else 0The Threshold
Zero is the threshold where the decision flips. Cross it and the neuron fires; stay below and it stays quiet.
Bias Moves the Threshold
Changing the bias slides that threshold. A larger bias makes the neuron fire more easily, a smaller one makes it harder.
A Line in the Data
With two inputs, the firing rule draws a straight line on a graph. Points on one side say yes, points on the other say no.
The Decision Boundary
That line is the decision boundary. It splits your feature space into two regions, one class on each side.
Weights Tilt the Line
The weights control the angle and steepness of the boundary. Adjusting them rotates the dividing line across your data.
Linear Means Straight
This is a linear decision: the boundary is always a straight line or flat plane. It cannot bend or curve around the data.
Linearly Separable Data
If one straight line can split your classes cleanly, the data is linearly separable. A single neuron handles this case perfectly.
The Hard Edge Problem
The step's hard edge jumps abruptly from 0 to 1. That sharp jump has no useful slope, which makes gradient-based learning tricky later.
A Tiny Classifier
Combine the weighted sum with a step and you have a working binary classifier in two short lines of Python.
score = w1 * x1 + w2 * x2 + b
label = 1 if score >= 0 else 0Quick Check
Think about the shape a single neuron can carve.
Recap
The step function turns a score into 0 or 1 at a threshold. With two inputs it draws a straight decision boundary, splitting linearly separable data. 📏
常见问题解答
「阶跃函数与线性决策」课时是免费的吗？
是的 — 「阶跃函数与线性决策」的完整文本可在网页上免费阅读。要进行交互式练习（内置代码编辑器和全天候 AI 导师）并解锁 Deep Learning Academy 课程的其余内容，请升级到 CoddyKit PRO。 Deep Learning Academy 课程共包含 4 节课。
「阶跃函数与线性决策」这节课中我会学到什么？
了解感知器如何划分两个类别 你通过在浏览器中直接运行的动手代码来练习 Deep Learning Academy，全天候 AI 导师会在你学习这节课的过程中回答你的问题。
学习 Deep Learning Academy 需要有经验吗？
无需任何先前经验。CoddyKit 上的 Deep Learning Academy 课程适合初学者到高级学习者，你可以从这里开始或从头开始，按照自己的节奏学习。 这是第 2 节课，共 4 节。
「阶跃函数与线性决策」课时需要多长时间？
大多数 CoddyKit 课程大约需要 5–10 分钟。每节课都很精短且互动，所以你能稳步进步，并在网页和应用中从离开的地方继续。
我能在这节 Deep Learning Academy 课中编写并运行代码吗？
能。每节 Deep Learning Academy 课都包含内置代码编辑器，你可以在浏览器中直接编写并运行真实代码，并获得即时 AI 反馈 — 无需本地设置。
此课程中的所有课时
- 权重、偏置与加权和
- 阶跃函数与线性决策
- 从零开始编写感知器
- XOR 问题：为何一个神经元还不够