helenak

what to input for ???in_value_raster??? in zonal statistics as table

Discussion created by helenak on Jun 9, 2012
Latest reply on Jun 14, 2012 by Lady_Jane
System ArcGIS 9.3

I have some polygon shape files of bird distributions.
Each file has two groups of distribution types: summer and winter.
For each distribution type,
I want calculate the average monthly temperature respectively.

Some seniors have advised to use zonal statistics as table,
since I have feature datasets.
However, one of the input fields of zonal statistics as table confused me.
It was ???in_value_raster???.
I do not know which raster file to be input,
because I only have feature datasets at hand.

According to ArcGIS Desktop help,
two possible solutions are ???feature to raster??? or ???polygon to raster.???
However, I found their output cell sizes were different.
The one of ???feature to raster??? was 16762,
and the other ???polygon to raster??? was 17000.
(The original feature datasets has grid cell size around 100 km in Behrmann projection.)

Please kindly help with the following questions and thank you in advance.

Questions:
1. Please kindly advise if it is possible to input feature datasets or the alternative in the field ???in_value_raster??? without converting shapefile into raster data sets in advance. (in order to want to save space storing raster datasets)

2.  Please kindly advise why the output cell sizes could be different using ???feature to raster??? or ???polygon to raster.??? Which output cell size is more close to the original cell size? Why?

3.  How to make the output cell size of raster dataset the same as the original   shapefile?

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