
Outline the numpy stack as a data science prerequisite, and highlight numpy, matplotlib, scipy, and pandas, along with key prerequisites in linear algebra, probability, and Python.
Compare Python lists and NumPy arrays, showing how lists support concatenation and repetition while NumPy arrays enable element-wise math, broadcasting, and vector operations.
Learn how to compute the NumPy dot product using direct definition, element-wise multiplication, indexing, and the dot function, and explore the magnitude and cosine-angle approach.
Measure dot product performance by comparing numpy arrays with Python lists; results show numpy is about 60–68x faster, illustrating how to avoid for loops for efficiency.
Learn how to represent matrices with numpy arrays, access and manipulate them via indexing and slicing, perform matrix multiplication, determinants, inverses, diagonals, eigenvalues/eigenvectors, and hermitian tricks.
Generate data with numpy by creating zeros, ones, and identity matrices, then sample from uniform or normal distributions to build synthetic data and study statistics like mean, variance, and covariance.
practice a numpy-based speed test by implementing matrix multiplication with lists, compare to dot product performance, discuss solutions on the forum, and explore how input size affects timing.
Explore how the NumPy stack powers machine learning fundamentals, emphasizing core operations and theory; learn how linear regression and deep neural networks use matrix multiplication, weights, biases, and activations.
Explore Matplotlib to visualize data for machine learning, focusing on line charts, scatter plots, histograms, and image plots for model development and computer vision.
Explore scatter plots as a two-dimensional visualization by generating 100 observations from a standard normal, plotting x[:,0] against x[:,1], and using color to distinguish classes for classification or clustering.
Plot histograms with numpy to visualize data distributions from 10,000 standard normal and uniform samples. Plot with 50 bins to reveal a bell curve around zero and the 95% range.
Learn the basics of NumPy, Matplotlib, Pandas, and SciPy for building and visualizing machine learning models. Use basic plots to visualize linear regression, classification, and finance data.
Introduce the Pandas section and cover loading and writing csv files, dataframes versus numpy arrays, and basic operations like selecting rows and columns, applying functions, and plotting.
Explore selecting rows and columns in a data frame with square brackets, iloc, and loc, and distinguish between series and data frames while converting to numpy arrays.
Learn how to use the apply function to operate on each row or column of a data frame, avoiding for loops, and create a year column from a date string.
Generate donor or concentric circles data set, build a pandas data frame, derive columns for X1 squared, X2 squared, and X1 times X2, then save csv without headers or index.
Learn how pandas uses data frames and series to load tabular data, apply transformations, and perform simple plotting, with finance-oriented examples like date indexing and returns.
Compute the pdf, cdf, and log pdf of the standard normal using scipy.stats Norm, then plot these with matplotlib and note applicability to other distributions like beta or gamma.
Apply SciPy to an edge-detection exercise using the Sobel filters. Convolve grayscale images with h_x and h_y, then compute gradient magnitude by squaring, adding, and square-rooting element-wise.
Practice key NumPy stack concepts with hands-on exercises: eigenvectors and eigenvalues, central limit theorem demonstrations, MNIST mean images, image rotation, symmetry tests, and visual datasets with pandas CSV export.
Navigate the NumPy stack in Python course when you lack math prerequisites by following a personalized catch-up plan that reinforces calculus, linear algebra, and probability.
Learn to implement regression in code using the numpy stack in Python, applying linear regression and random forest regressors to airfoil self-noise data, with train-test splits, predictions, and r-squared evaluation.
Define a feature vector as a row in an n by d data matrix, where each feature helps predict the output, and note domain knowledge and polynomial expansions as approaches.
Recognize that all data is the same across any dataset, and that all machine learning interfaces are the same, with fit and predict as core actions.
Avoid shortcuts when selecting a model; learn the algorithms and experiment. Compare linear models, ensembles, SVMs, and deep learning to highlight trade-offs.
Discover how machine learning works as a geometry-based black box, with inputs, outputs, and a reusable API; learn the basic workflow: load data, build, train, and evaluate models.
Clarify the meaning and purpose of the appendix and FAQ in this course, showing optional access to common questions, Q&A, and supplementary material that address code, notebooks, and exercises.
Ever wondered how AI technologies like OpenAI ChatGPT, GPT-4, DALL-E, Midjourney, and Stable Diffusion really work? In this course, you will learn the foundations of these groundbreaking applications.
Welcome! This is Deep Learning, Machine Learning, and Data Science Prerequisites: The Numpy Stack in Python.
One question or concern I get a lot is that people want to learn deep learning and data science, so they take these courses, but they get left behind because they don’t know enough about the Numpy stack in order to turn those concepts into code.
Even if I write the code in full, if you don’t know Numpy, then it’s still very hard to read.
This course is designed to remove that obstacle - to show you how to do things in the Numpy stack that are frequently needed in deep learning and data science.
So what are those things?
Numpy. This forms the basis for everything else. The central object in Numpy is the Numpy array, on which you can do various operations.
The key is that a Numpy array isn’t just a regular array you’d see in a language like Java or C++, but instead is like a mathematical object like a vector or a matrix.
That means you can do vector and matrix operations like addition, subtraction, and multiplication.
The most important aspect of Numpy arrays is that they are optimized for speed. So we’re going to do a demo where I prove to you that using a Numpy vectorized operation is faster than using a Python list.
Then we’ll look at some more complicated matrix operations, like products, inverses, determinants, and solving linear systems.
Pandas. Pandas is great because it does a lot of things under the hood, which makes your life easier because you then don’t need to code those things manually.
Pandas makes working with datasets a lot like R, if you’re familiar with R.
The central object in R and Pandas is the DataFrame.
We’ll look at how much easier it is to load a dataset using Pandas vs. trying to do it manually.
Then we’ll look at some dataframe operations useful in machine learning, like filtering by column, filtering by row, and the apply function.
Pandas dataframes will remind you of SQL tables, so if you have an SQL background and you like working with tables then Pandas will be a great next thing to learn about.
Since Pandas teaches us how to load data, the next step will be looking at the data. For that we will use Matplotlib.
In this section we’ll go over some common plots, namely the line chart, scatter plot, and histogram.
We’ll also look at how to show images using Matplotlib.
99% of the time, you’ll be using some form of the above plots.
Scipy.
I like to think of Scipy as an addon library to Numpy.
Whereas Numpy provides basic building blocks, like vectors, matrices, and operations on them, Scipy uses those general building blocks to do specific things.
For example, Scipy can do many common statistics calculations, including getting the PDF value, the CDF value, sampling from a distribution, and statistical testing.
It has signal processing tools so it can do things like convolution and the Fourier transform.
In sum:
If you’ve taken a deep learning or machine learning course, and you understand the theory, and you can see the code, but you can’t make the connection between how to turn those algorithms into actual running code, this course is for you.
"If you can't implement it, you don't understand it"
Or as the great physicist Richard Feynman said: "What I cannot create, I do not understand".
My courses are the ONLY courses where you will learn how to implement machine learning algorithms from scratch
Other courses will teach you how to plug in your data into a library, but do you really need help with 3 lines of code?
After doing the same thing with 10 datasets, you realize you didn't learn 10 things. You learned 1 thing, and just repeated the same 3 lines of code 10 times...
Suggested Prerequisites:
matrix arithmetic
probability
Python coding: if/else, loops, lists, dicts, sets
you should already know "why" things like a dot product, matrix inversion, and Gaussian probability distributions are useful and what they can be used for
WHAT ORDER SHOULD I TAKE YOUR COURSES IN?:
Check out the lecture "Machine Learning and AI Prerequisite Roadmap" (available in the FAQ of any of my courses)