geomImshow

fun geomImshow(rasterData: RasterData, norm: Boolean = true, vmin: Number? = null, vmax: Number? = null, extent: List<Number>? = null, showLegend: Boolean = true, colorBy: String = "paint_c"): Feature

Displays image specified by RasterData.

This geom is not as flexible as geomRaster() or geomTile() but vastly superior in the terms of rendering efficiency.

Notes

This geom doesn't understand any aesthetics. It doesn't support color scales either.

Examples

Return

Layer object.

Parameters

rasterData

Specifies image type, size and pixel values. See RasterData.create.

norm

default = true.

  • true - luminance values in grey-scale image will be scaled to [0-255] range using a linear scaler.

  • false - disables scaling of luminance values in grey-scale image. This parameter is ignored for RGB(A) images.

vmin

default = null. Defines the data range used for luminance normalization in grey-scale images. This parameter is ignored for RGB(A) images or if parameter norm = false.

vmax

default = null. Defines the data range used for luminance normalization in grey-scale images. This parameter is ignored for RGB(A) images or if parameter norm = false.

extent

default = listOf(-0.5, ncol-0.5, -0.5, nrow-0.5). List of 4 numbers: (left, right, bottom, top). Defines image's bounding box in terms of the "data coordinates".

  • left, right: coordinates of pixels outer edge along the x-axis for pixels in the 1-st and the last column.

  • bottom, top: coordinates of pixels outer edge along the y-axis for pixels in the 1-st and the last row.

showLegend

default = true. Greyscale images only. false - do not show legend for this layer.

colorBy

default="paint_c" ("fill", "color", "paint_a", "paint_b", "paint_c"). Define the color-aesthetic used by the legend shown for a greyscale image.