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This question should be easy! I am using spplot for visualizing a map with suitable results. However, I would like to know how to set the limits of z, because the values are not being discriminated.

My data frame (df) is: long, lat, Z

spplot(df, "Z") 

Figure

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    what does range(df$Z) say? Because it looks like you've got something in the region of 10^57 in there. Some kind of missing value code? – Spacedman Apr 28 '16 at 20:18
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Spacedman ist probably right but you could subset your dataframe before plotting like:

df <- df[df$Z < 300,]
spplot(df, "Z")
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This looks indeed like some sort of missing value (as suggested by @Spacedman). Anyway, as a straightforward alternative to subsetting your data (as suggested by @nebi), you could simply use the zcol argument inside spplot to display only a desired range of values. Here is a reproducible example.

library(raster)
rst <- raster(volcano)

## no 'zlim' specified
p1 <- spplot(rst)
## 'zlim' specified
p2 <- spplot(rst, zlim = c(100, 175))

library(gridExtra)
grid.arrange(p1, p2, ncol = 2)

spplot

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