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Spacedman
Spacedman
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I have a shapefile containing 38 polygons i.e. 38 states of a country. This shapefile is overlaid on a raster. I need to extract/reclassify pixel above a certain value, specific to each polygon. For example, I need to extract the raster pixels> 120 for state/polygon 1, pixels> 189 for polygon 2 etc with the resulting raster being the extracted pixels with value 1 and everything else as NoData. Hence, it seems like I need to extract first and then reclassify.

I have the valueesvalues, for extraction, saved as a data frame with a column containing names, matching the names of the states,which is stored as an attribute "Name""Name" in the shapefile.

Any suggestion on how I could go about this? Should I extract the raster for each state into 38 separate rasters, then do reclassify ()reclassify() and then mosaicmosaic to make one raster i.e. the country?

1 down vote favorite

I have a shapefile containing 38 polygons i.e. 38 states of a country. This shapefile is overlaid on a raster. I need to extract/reclassify pixel above a certain value, specific to each polygon. For example, I need to extract the raster pixels> 120 for state/polygon 1, pixels> 189 for polygon 2 etc with the resulting raster being the extracted pixels with value 1 and everything else as NoData. Hence, it seems like I need to extract first and then reclassify.

I have the valuees, for extraction, saved as a data frame with a column containing names, matching the names of the states,which is stored as an attribute "Name" in the shapefile.

Any suggestion on how I could go about this? Should I extract the raster for each state into 38 separate rasters, then do reclassify () and then mosaic to make one raster i.e. the country?

I have a shapefile containing 38 polygons i.e. 38 states of a country. This shapefile is overlaid on a raster. I need to extract/reclassify pixel above a certain value, specific to each polygon. For example, I need to extract the raster pixels> 120 for state/polygon 1, pixels> 189 for polygon 2 etc with the resulting raster being the extracted pixels with value 1 and everything else as NoData. Hence, it seems like I need to extract first and then reclassify.

I have the values, for extraction, saved as a data frame with a column containing names, matching the names of the states,which is stored as an attribute "Name" in the shapefile.

Any suggestion on how I could go about this? Should I extract the raster for each state into 38 separate rasters, then do reclassify() and then mosaic to make one raster i.e. the country?

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tg110
tg110
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Reclassifying raster/extracting pixel values conditionall over multipolygon shapefile

1 down vote favorite

I have a shapefile containing 38 polygons i.e. 38 states of a country. This shapefile is overlaid on a raster. I need to extract/reclassify pixel above a certain value, specific to each polygon. For example, I need to extract the raster pixels> 120 for state/polygon 1, pixels> 189 for polygon 2 etc with the resulting raster being the extracted pixels with value 1 and everything else as NoData. Hence, it seems like I need to extract first and then reclassify.

I have the valuees, for extraction, saved as a data frame with a column containing names, matching the names of the states,which is stored as an attribute "Name" in the shapefile.

Any suggestion on how I could go about this? Should I extract the raster for each state into 38 separate rasters, then do reclassify () and then mosaic to make one raster i.e. the country?