I wanted to download some course material on RL shared by the author via Google drive using the command line.  I got a bunch of stuff using wget a folder in google drive was a challenge. I looked it up in SO which gave me a hint but no solution. I installed gdown using pip and then used: gdown --folder --continue https://drive.google.com/drive/folders/1V9jAShWpccLvByv5S1DuOzo6GVvzd4LV if there are more than 50 files you need to use --remaining-ok and only get the first 50. In such a case its best to download using the folder using the UI and decompress locally. Decompressing from the command line created errors related to unicode but using the mac UI I decompressed without a glitch.

### Data Science Glossary - O

 OLAP cube.  (Image credit: Wikipedia)
OLAP
Online Analytical Processing OLAP is the technology behind many Business Intelligence (BI) applications. OLAP is a powerful technology for data discovery, including capabilities for limitless report viewing, complex analytical calculations, and predictive “what if” scenario (budget, forecast) planning.
OLAP cube
is a multidimensional dataset. The main operations are:
Slice - picking a rectangular subset of a cube by choosing a single value for one of its dimensions, creating a new cube with one fewer dimension.
Dice - produce a sub-cube by picking specific values of multiple dimensions.
Drill Down/Up - navigation among levels of data ranging from the most summarized (up) to the most detailed (down).
Pivot - rotates the cube in space to see its various faces
Roll-up - summarizing the data along a dimension
One hot encoding
Is where each word or feature gets represented by a unit vector for a specific dimension. The shortcoming is that similar items are encoded as similar to different items.
Optimization algorithm
is algorithm used to minimize the error for a model such as a neural network.
Overfitting
in machine learning is when we fitting patterns in the noise rather than signal. The NN does not have a way to penalize/ignore noise/or tell noise apart from the signal