How to apply log scale when plotting sf data?

Question

I want to plot some sf data, similar to this example:

library (sf)

fishnet <- st_make_grid ()
n <- length (fishnet)
vals <- rlnorm (n)
fishnet <- st_sf (fishnet)
fishnet <- cbind (fishnet, vals)

c_ramp <- colorRampPalette (c ("azure", "yellow", "red"))
plot (fishnet, pal  = c_ramp)

I want to use a log scale for the legend and color scheme, but the plot function doesn't seem to support log scale out of the box. Is there any painless way around that?

lcgodoy · Answer 1 · 2020-05-14T19:53:47.150

1

According to the sf package documentation, the plot method for sf objects have and argument (or parameter) called logz, which has as default FALSE. If you set logz = TRUE, the variable that you are trying to plot is displayed on the log-scale.
You can find an example below:

plot(fishnet["vals"], logz = TRUE)

edited May 14 '20 at 19:53

answered May 13 '20 at 22:53

lcgodoy

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4

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This answer is quite sparse, and could use a documentation reference and a few sentences to frame it as a high-quality answer. – Vince May 14 '20 at 00:40
Just included the requested information. – lcgodoy May 14 '20 at 19:54

Jeffrey Evans · Accepted Answer · 2017-11-17T17:07:54.573

0

In looking at the code underlying the plot_sf function, it seems like the path of least resistance is to just create a new column with the log transformed values. If one could call y separately you could transform the values on the fly but, currently the plot generic is not written in that way.

fishnet$log.vals <- log(fishnet$vals)
plot(fishnet[,"log.vals"], pal  = c_ramp)

edited Nov 17 '17 at 17:07

answered Nov 17 '17 at 16:13

Jeffrey Evans

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How to apply log scale when plotting sf data?

2 Answers2