Starting today, recreational weed is legal in Canada. This news has some how lead me to find Cannabis Curve, a mathematical equation to draw Cannabis….!!!

So to celebrate? being 2nd country in the world (1st was Uruguay) to legalize the green stuff for fun, I decided I’ll try drawing cannabis curve with ggplot. Here’s the final results.

Here’s the step I took, because I couldn’t really understand the mathematical equation, so I’ve break it down step by step to sort of understand what each part of equation is doing.

```
library(tidyverse)
cannabis <- tibble(
t = seq(-pi,pi, length.out=1000),
r1 = (1+.9*cos(8*t)), ## this will draw 8 petals ## this number determines number of leafs!
r2 = r1 * (1+.1*cos(24*t)), ## this make it pointy
r3 = r2 * (.9+0.5*cos(200*t)), ## this makes it jaggy
r4 = r3 * (1+sin(t)), ## Hmm.. I think I want to rorate it 90 degree...
r4_alt = r3 * (1+sin(t-pi/2)), ## one way to do it...
r = (1+.9*cos(8*t)) * (1+.1*cos(24*t)) * (.9+0.5*cos(200*t)) * (1+sin(t)) ## Put all in line line!
)
cannabis %>%
ggplot(aes(x=t, y=r1)) +
geom_path(color="#7ABA71", size=2) +
coord_polar() +
theme_void(base_family="Roboto Condensed") +
labs(title = "(1+.9*cos(8*t) draws 8 petals")
```

```
cannabis %>%
ggplot(aes(x=t, y=r2)) +
geom_path(color="#7ABA71", size=2) +
coord_polar() +
theme_void(base_family="Roboto Condensed") +
labs(title = "(1+.9*cos(8*t) * * (1+.1*cos(24*t)) makes the tip pointy")
```

```
cannabis %>%
ggplot(aes(x=t, y=r3)) +
geom_path(color="#7ABA71", size=0.5) +
coord_polar() +
theme_void(base_family="Roboto Condensed") +
labs(title = "(1+.9*cos(8*t) * * (1+.1*cos(24*t)) * (.9+0.5*cos(200*t)) makes zaggy")
```

```
cannabis %>%
ggplot(aes(x=t, y=r4)) +
geom_path(color="#7ABA71", size=0.5) +
coord_polar(start=pi/2) +
theme_void(base_family="Roboto Condensed") +
labs(title = "(1+.9*cos(8*t) * * (1+.1*cos(24*t)) * (.9+0.5*cos(200*t)) * (1+sin(t)) - OK Cool, Now 2 leaves are small!", subcaption="Notice I used start=pi/2 to rotate!")
```

```
cannabis %>%
ggplot(aes(x=t, y=r)) +
geom_polygon(fill="#499b4a", color="#74Ba71", size=0.1) +
coord_polar(theta="x", start=pi/2) +
theme_void(base_family="Roboto Condensed") +
labs(title = "Instead of using geom_path, I used geom_polygon")
```

I couldn’t figure out how to “crop” the polar coordinate image, so there’s lots of white space on final image, but I like my little cannabis!

I couldn’t find way to crop the image, but I realized I just need to plot the above in Cartesian coordinate…!

```
# To translate polar coordinate to cartesian, I can use below
## x = r * cos(theta)
## y = r * sin(theta)
cannabis <- cannabis %>% mutate(
x = r * cos(t),
y = r * sin(t)
)
cannabis %>%
ggplot(aes(x=x, y=y)) +
geom_polygon(fill="#499b4a", color="#74Ba71", size=0.1) +
theme_void(base_family="Roboto Condensed") +
labs(title = "Cannabis on Cartesian Coordinate")
```

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