Data Manipulation

The scripting environment provides tools for manipulating geo-data.


The scripting language used by LISEM is specifically aimed at manipulating geodata files. It extends the language by allowing in-line references to geo-data files from your working directory. Otherwise, it is based on the c-style language Angelscript, and features classes, functions, loops, if/else, function callbacks and many other things. The Command line allows you to perform single-line calculations. Here are some example calculations you can do in the command line

dem.tif = dem.asc

Loads a map called dem (in asc format) and saves it to GeoTiff format. = Slope(

Calculates the Slope of a map.

calc.tif = dem.tif +^2.0 + sin(atan(sqrt(

Compound calculations with differing map formats. Note that all raster must have the same number of rows and columns. = Accuflux(,

More complex geo-spatial algorithms such as flux accumulation

dem_warped.tif = RasterWarp(,GeoProjectionFromESPG(3350))

Warping using the GDAL libraries.


Add a layer to the mapviewer.

layers.tif = {,,WindowAverage(,100))

Use curly brackets to save a list of raster to a multi-band file. = layers.tif[0] + layer.tif[1]

Use square brackets to use a specific band of a multi-band raster file

lines.shp = LineDetect(Slope(

Detect linear features in terrain, and store them as a shapefile.

bridges.shp = rivers.shp | roads.shp

Logical operators for shapefiles. This finds the intersection between rivers and roads.

test.tbl[3] = test.tbl[0] + test.tbl[1] * test.tbl[2]

Table objects also support operators. The type of the table determines what operators do.


Print a number to the output window. The Map…Red functions act to reduce a map to a single number.

test.tif += 100

Collapsed operators applied directly to a file.

test.tif +=

Collapsed operators applied directly to a file.

Some notes on these examples: • The syntax here differs from the scripting language in the sense that no main() function is needed. Additionally, there is no need to put the semicolon (;) at the end of the line. • The full scripting language is available. Keep in mind that for most calculations, the number of rows and columns for each map must be equal.