Hi, many thanks for those who reply ,there are the original query and the answers as will:
Warm Regards Osame Alkaaby ************************************************************************ *************************************************** Greeting I have got serious problem with "IFF" function. Actually I have three raster map ,now (may be increased to 4 later) with the same georefrence and all of them having class domain (map1=Canopy cover, map2=Erosion, map3=EC).I want to produce new map (Desertification map) with new class domain, for this I should use "IFF" function more than one time. I have no idea how can I prepare this script or function. For example I want to tell ILWIS : Iff map1 has class "IV" and map2 has class "V" and map3 has class "III",then return class "SEVER" for new map desertification map) and iff map1 has class "I" and map2 has class "II" and map3 has class"III", then return class"LOW" for the new map and so...I has tried some functions but I got error. May be I made a mistake in the number of parenthesis or some things else. I am new with this kind of work, so it would highly appreciated if you help and guide me in this issue. ************************************************************************ ************************************************ The syntax you are looking for is: newmap=iff((map="IV") and (map2="V") and (map3="IIII"),"SEVER",iff((map1="I") and (map2="II") and (map3="III"),"LOW",?)) For more info refer to the online help topic "Map and Table Calculation - IFF( ) function. Regards, Jelger Kooistra ************************************************************************ ********************************************** Sometimes, the use of those parameters needs a lot of concentration. You may work with temporary maps, by example you prepare, temporary map one, choosing the first variable, like this temporary_map_1:= iff((variable1=?),map2,?) that means the temporary map 1 will be just the result of 1st variable, then combine tmp_map_2:= iff((variable=??),map3,??) to include the use of 2nd variable Be careful on the use of parenthesis, because of sintaxis, if not, you will always get problems SIT CENTAFAO ************************************************************************ *********************************************** ________________________________________________________ To leave the ILWIS-LIST discussion list, send a email with 'unsubscribe ilwis-list' in the body to '[EMAIL PROTECTED]'
