Latest Contributions by VincentLaunstorfer

Hi, I have a line shapefile and I would like to extract elevation value from a raster DEM in order to create an elevation profile. As shown attached... Is there a smart was of doing this in ArcGIS? Thanks ... View more

Hi, I got a shaded-relief image for North America from the USGS but it is not georeferenced. Attached are the characteristics of the image in ArcCatalog, and the extent was filled-in by the .tfw file I made, as attached. Looking at the image, I guessed the upper-left corner was long -130 and lat +60. Still according to the image, I found the upper-right corner long -50 and lat +60 while bottom-left long -130 and lat +15 With 9600 columns, the cell size would be: (130-50) / 9600 = 0.008333333°, which is 30''. Looks good And with 7240 rows, the cell size would be: (60-15) / 7240 = 0.006215469°, whi ch is roughly 22''. Not as good. Even with a .tfw with these values do not update the Cell Size in the image in ArcCatalog. Why? Usually, it does... Also, would it be possible to have rectangular pixel? I guess why not... Does the number of bands, which are 3, change anything in georeferencing the image? How could I convert the image from 3 bands to 1 bamd only? Thanks for your help ... View more

Hi, I have a SRTM30 tile named E140S10.gif attached, containing 600 column and 750 rows. The upper left corner is 140° W, thus +140 and 10°S, thus -10, according to the filename... In a text editor, I tried to create a georeferenced file .gfw (attached): 0.066666666 0.000000 0.000000 -0.066666666 140 -10 I calculated the 0.06666666 by dividing 40° (width of the tile) / 600 pixels = 0.0666666666 and 50° (height of the tile) / 750 pixels = 0.0666666666 The gfw seems correct and has the same name as the .gif file, located in the same directory, but do not open in ArcMap. I get an error "missing spatial reference...". I don't understand why? ... View more

Hi,   In ArcGIS Advanced for Desktop 10.2, I am trying to calculate a field "ELEV_METER" in a shapefile with an expression and code-block as here:   expression = "getElev(double(!ELEV!))" codeblock = """def getElev(elev):      if elev <> 0:           return !ELEV!"""  arcpy.CalculateField_management(fc, "ELEV_METER", expression, "PYTHON_9.3",codeblock)   trying to apply ressources from ESRI: http://resources.arcgis.com/en/help/main/10.1/index.html#//00170000004m000000   The calculate field should be done only if the field ELEV is not 0, then the if statment...   But is does not work! Any guess?   Cheers ... View more

Hi,   I have a python tool in which an SQL query string make a layer:   "NAME " + "LIKE " + "'" + strField_NAME + "'"   However, it appears that I have some names containing quotes in my dataset! For example, Jimmy's Peak containing a single quote and thus crashing my script...   Is there any sort of escape character I could use in a Python script in order to build an SQL query?   For the time being, the query builds as NAME LIKE + 'Jimmy' because the name contains a single quote... and it should be NAME LIKE + Jimmy's Peak ... View more