PCA (Data Shrinker)
PCA makes a huge table smaller while trying to keep the most important pattern.
What it does
PCA makes a huge table smaller while trying to keep the most important pattern.
Columns: The kinds of facts in a table • Spread: How different the numbers are
How it works
- Look for columns that say almost the same thing.
- Find the strongest direction in the data.
- Keep fewer columns so the computer has less to carry.
Uses & Applications
- A phone can shrink image data before another AI studies it.
- A science tool can simplify a giant spreadsheet.
- A dashboard can show a big pattern on a simple chart.
In short
PCA is like squishing a 3D object into a flat shadow.
Try it yourself
Find the best direction for dot shadows
Imagine shining a light so that each orange dot leaves a blue shadow on one line. Keep the shadows spread out.
Your turn
Change one setting at a time. Reset example puts everything back.
Project onto one principal direction
Step 1Why this happens