Write a Maxent Prediction Grid as a PNG Image

Converts a GridFloat prediction grid to a colour PNG image using the canonical Maxent colour ramp (red = high, blue = low). Optionally overlays presence and test-point locations, and renders a small legend.

Usage

maxent_write_prediction_png(
  grid,
  filename,
  presence_rows = NULL,
  presence_cols = NULL,
  test_rows = NULL,
  test_cols = NULL,
  mode = "plain",
  legend = TRUE,
  width = 800L,
  height = 600L
)

Arguments

grid

External pointer to a GridFloat prediction grid (e.g. from maxent_project_cloglog).

filename

Character: path for the output PNG file.

presence_rows

Integer vector of presence row indices (0-based) or NULL (default).

presence_cols

Integer vector of presence column indices (0-based) or NULL (default).

test_rows

Integer vector of test-set row indices (0-based) or NULL (default).

test_cols

Integer vector of test-set column indices (0-based) or NULL (default).

mode

Colour mode passed to maxent_color_ramp: one of "plain" (default), "log", "blackandwhite", or "redandyellow".

legend

Logical: draw a colour-bar legend (default TRUE).

width

Integer: PNG width in pixels (default 800).

height

Integer: PNG height in pixels (default 600).

Value

Invisibly returns filename.

Examples

if (FALSE) { # \dontrun{
pred <- maxent_project_cloglog(model, list(g1, g2), c("bio1", "bio12"))
maxent_write_prediction_png(pred, "prediction.png")
} # }