Related to a "field calculator" interface for modifying field attributes.
2
votes
2answers
37 views
How to calculate land cover inside the buffer zones?
In one Shape file I have created 1200 buffer zones Around coordinates. I created a field and calculated the buffer zones area in hectares.
Then I clipped different landcover layers to the buffer ...
10
votes
2answers
7k views
How to calculate polygon areas in QGIS?
Hi I would like to simply calculate areas of a area-shape file in square meters or in acres (ha).
I didn't find that functionality in the vector tools.
Could anyone here help me with that?
0
votes
1answer
76 views
How to calculate polygon areas in acres or square miles instead of feet?
I have a layer in State Plane NAD83. When I use "Vector|Geometry Tools|Add/export geometry columns" or Field Calculator they both create the area in feet. What if I want acres or square miles? Thanks
...
2
votes
1answer
61 views
Raster calculator - reduce all value above certain value
I have a probably quite simple question: I have a raster with elevations above 2000m that I want to "cut" to 1800m. I cannot quite figure out the correct string and most simple way to do this in the ...
2
votes
1answer
165 views
field calculation in arcgis
i have a data which contain a code of area an value of area in shapefile, ex.:
area|value
1|33
1|43
1|31
2|12
2|43
3|66
3|76
the question is how to calculate total value per area with arcgis, i ...
1
vote
0answers
148 views
Raster calculator error 000539 - cannot create weak reference to 'classobj' object
I was - like many times before - trying to clip a raster with the raster calculator (raster * 1 with shapefiles as mask). Now - the following error keeps popping up:
ERROR 000539: Error running ...
1
vote
1answer
305 views
Problem with raster calculator
When working with raster calculator there is an error 000539? The program failed to create a common raster map. I don't know what to do. I did the same in school without any problems. But now, on my ...
4
votes
1answer
426 views
How to get latitude /longitude in Degree Minute Second (DMS) using QGIS field calculator?
I have come up with the following expression to convert 5.1234 to 5° 7`24.24"
toint ($x) || '° ' || toint((($x) - toint ($x)) * 60) ||'`' || substr( (tostring(((($x) - toint ($x)) * 60) - ...
4
votes
4answers
4k views
Why doesn't the Field Calculator work in ArcGis 10?
When I try to calculate a field nothing happens. I have always been able to just select the field, open the field calculator and type = and the new number. This is frustrating because the other GIS ...
3
votes
1answer
272 views
Sum up area left “underneath” polygons in QGIS?
I have an area shape layer and multiple other area shape layers. Now I would like to calculate how much space (square kilometers or percentage of area) of the polygons of this area layer is NOT ...
5
votes
2answers
191 views
Raster calculation confusion
I need to do some raster calculation, I've been trying to make it work but I am not sure everything is working properly.
I need to apply a formula, but I am unsure if I am doing it properly. The ...
1
vote
2answers
135 views
How to select only areas bigger than x acres?
I would like to create a new shapefile from another area shapefile. The new shapefile should only contain all areas that are bigger than 5 acres (10.000 m²).
How do I do this?
0
votes
1answer
232 views
Error when using .isalnum in ArcGIS fieldcalculator
ArcGIS keeps throwing an error when I use the following script in the field calculator, using Python:
pre-logic script code:
y= ()
if !fieldx!.isalnum():
y= 1
else:
y= 0
Fieldy=
y
The ...
4
votes
2answers
948 views
VBA functions use in ArcGIS Field Calculator
Would this be ok to use them for the field calculator in ArcGIS 9.3 ? See here MS Excel VBA Functions
Or should I fix them in MS Excel and save as a file and then use the join with the shapefile or ...
5
votes
3answers
204 views
Calculating order of points along a line
I have a shape file with transportation lines and another file with all bus stops along each line (with an attribute which links stops with specific lines to which they belong).
I need to calculate ...
3
votes
4answers
840 views
Field Calculator in ArcGIS - keep equation
I'm using Arc 9.3.1 (Arc Editor).
In edit mode I've created a simple field calculation. For example's sake let's make it [Field3] = [Field1] + [Field2]
How do I 'keep' the calculation so Field3 ...
4
votes
2answers
3k views
“If then” VB Script code (or Python) equivalent to SQL's IN ('x','y',z') expression in ArcGIS Field Calculator question?
we need just like the following, only with multiple records selected... have tried the "xyz" in (1,2,3,4,5) SQL code but of course VB Script wants something else.
dim f2
if [field1] = "foo" then
f2 ...
