igg - Interpolated grid to grid

Name

igg — Interpolated grid to grid operation

Syntax

igg add | sub | mul | div | lt | gt | rep [und] workspacename

Description

General grid to grid operation that does not require that the grids involved has the same size and position.

Arguments

workspacename

Name in workspace where the second grid is present. Must always be present.

add

The grids are added.

sub

The grid in workspacename is subtracted from the active grid.

mul

The grids are multiplied.

div

The active grid is divided by the grid in workspacename.

lt

The result grid in active will be minimum of either of the two grids.

gt

The result grid in active will be maximum of either of the two grids.

rep

Replace all undefined areas with values from grid in workspacename.

und

Undefined values returned from the interpolation should be used in the new dataset.

Examples

Ex.1: Adding grids of unequal dimension

# Adding grids of unequal dimension
z                    ;# Erase screen
win demo             ;# Get demo window (450000 460000 6450000 6460000 1000 4000)
spe bgc whi          ;# Specify background color to white
mak ran 12 z 100 700 ;# Make 12 random points between 100 and 700
grp 222 222          ;# Make grid of dimension 222 x 222
eli gt 500           ;# Eliminate greater than 500
mhi mygrid           ;# Save the grid
ewi 25               ;# Expand the grid 25% in xy direction
mak ran 11           ;# Make 11 random points
grp 300 300          ;# Make grid of dimension 300 x 300
bol 2                ;# Draw the border layout
igg sub mygrid       ;# Add the two grids of different dimension together
ssc                  ;# Scale new dataset
acm n 11 sma         ;# Map the result grid using color bands

The above example produces this image.

Border layout of adding grids and result grid