how to control the width of ggpattern's fill pattern

Question

I want to decrease the width of ggpattern's fill pattern, making it looks like a black oblique line. However, my script did not work.

library(ggplot2)
library(ggpattern)

ggplot(sf_poly) + 
    geom_sf_pattern(pattern_fill = "transparent", fill = "transparent", 
        # pattern = 0,
        pattern_size = 0.2,
        pattern_type = 3,
        color = "transparent",
        size = 0.2) 

Answer 1

According to the packages "stripe" vignette you can use the pattern_density aesthetic to control the area the pattern fills i.e. in this case a lower pattern_density value will decrease the width of the stripes. Alternatively decreasing pattern_spacing will increase the number of stripes which would also reduce the stripe width for a fixed pattern_density value (more stripes filling a given area means each stripe must be smaller).