Create topography data: convexity, slope, and mean elevation.

Source: R/fgeo_topography.R

Create topography data: convexity, slope, and mean elevation.

fgeo_topography(elev, ...)

# S3 method for data.frame
fgeo_topography(
  elev,
  gridsize,
  xdim = NULL,
  ydim = NULL,
  edgecorrect = TRUE,
  ...
)

# S3 method for list
fgeo_topography(elev, gridsize, edgecorrect = TRUE, ...)

Arguments

elev

One of these:

  • A dataframe containing elevation data, with columns gx, gy, and elev, or x, y, and elev (e.g. fgeo.x::elevation$col).

  • A ForestGEO-like elevation list with elements xdim and ydim giving plot dimensions, and element col containing a dataframe as described in the previous item (e.g. fgeo.x::elevation).
...

Other arguments passed to methods.
gridsize

Number giving the size of each quadrat for which a habitat is calculated. Commonly, gridsize = 20.
xdim, ydim

(Required if elev is a dataframe) x and y dimensions of the plot.
edgecorrect

Correct convexity in edge quadrats?

Value

A dataframe of subclass fgeo_topography.

Acknowledgment

Thanks to Jian Zhang for reporting a bug (issue 59).

See also

fgeo_habitat().

Other habitat functions: fgeo_habitat(), tt_test()

Other functions to construct fgeo classes: fgeo_habitat()

Author

This function wraps code by Richard Condit.

Examples

assert_is_installed("fgeo.x")

elev_list <- fgeo.x::elevation
fgeo_topography(elev_list, gridsize = 20)

#> # A tibble: 400 x 5
#>       gx    gy meanelev convex slope
#>  * <dbl> <dbl>    <dbl>  <dbl> <dbl>
#>  1     0     0     365. -0.390  8.87
#>  2     0    20     365. -0.285 13.7 
#>  3     0    40     367.  0.210 14.4 
#>  4     0    60     367.  0.34  15.9 
#>  5     0    80     362. -0.255 20.8 
#>  6     0   100     358. -0.510 12.4 
#>  7     0   120     359. -0.28  17.1 
#>  8     0   140     360. -0.265 22.1 
#>  9     0   160     362.  0.055 24.3 
#> 10     0   180     364.  0.415 15.2 
#> # … with 390 more rows

elev_df <- elev_list$col
fgeo_topography(elev_df, gridsize = 20, xdim = 320, ydim = 500)

#> # A tibble: 400 x 5
#>       gx    gy meanelev convex slope
#>  * <dbl> <dbl>    <dbl>  <dbl> <dbl>
#>  1     0     0     365. -0.390  8.87
#>  2     0    20     365. -0.285 13.7 
#>  3     0    40     367.  0.210 14.4 
#>  4     0    60     367.  0.34  15.9 
#>  5     0    80     362. -0.255 20.8 
#>  6     0   100     358. -0.510 12.4 
#>  7     0   120     359. -0.28  17.1 
#>  8     0   140     360. -0.265 22.1 
#>  9     0   160     362.  0.055 24.3 
#> 10     0   180     364.  0.415 15.2 
#> # … with 390 more rows