R Line Plot

📈 R Line Plot (Beginner → Practical)

A line plot in R is used to visualize data trends over time or ordered values.
It’s commonly used in statistics, data analysis, economics, and research.

1️⃣ What is a Line Plot in R?

A line plot connects data points with straight lines to show change or trend.

Typical uses:

• Time-series data

• Growth/decline trends

• Comparisons over sequence

2️⃣ Basic Line Plot Syntax ⭐

• x → x-axis values

• y → y-axis values

• type = "l" → line plot (l = line)

3️⃣ Simple Line Plot Example

✔ Shows a basic increasing trend

4️⃣ Line Plot with Points + Line ⭐

• type = "o" → overplotted (line + points)

• pch → point symbol

5️⃣ Change Line Color, Width & Style 🎨

6️⃣ Line Plot for Time Series Data ⏳

✔ Used for business & analytics

7️⃣ Multiple Lines in One Plot ⭐⭐

✔ Very common in comparisons

8️⃣ Line Plot Using ggplot2 (Modern Way) ⭐⭐⭐

✔ Cleaner
✔ Professional look
✔ Widely used in data science

9️⃣ Common Mistakes ❌

❌ Forgetting type = "l"
❌ Mismatched x and y lengths
❌ No axis labels
❌ Overcrowded multiple lines

📌 Interview / Exam Questions

1. What does type = "l" mean in R?

2. Difference between type = "l" and type = "o"?

3. How to draw multiple lines in one plot?

4. Base R plot vs ggplot2?

5. How to customize line width and color?

✅ Summary

✔ Line plot shows trends over ordered data
✔ plot() is used in base R
✔ type = "l" creates a line plot
✔ lines() adds more lines
✔ ggplot2 is preferred for advanced visuals
✔ Very important for data analysis & exams