Replace a Polygon in a Spatial Polygon Data Frame - r

Question

I have a spatial polygon dataframe with several shapefiles. I would like to trim these shapefiles by elevation and replace the original shapefile in the dataframe. However, there appears to be an error when I try to replace the polygon after the trim. Currently, my plan is run though the following loop for each shapefile in the dataset. However, when I try dist[i,] <- temp3, I get the following error:
Error in match(value, lx) : 'match' requires vector arguments
In addition: Warning message:
In checkNames(value) :
attempt to set invalid names: this may lead to problems later on. See ?make.names
Any suggestions?
# Load spdf
dist <- rgdal::readOGR('critterDistributions.shp');
# Load elevational ranges
rangeElevation <- read.csv(file = 'elevationRanges.csv');
# Load altitude data
elevation <- raster('ETOPO1_Bed_g_geotiff.tif');
# Tidy up CRSes
crs(elevation) <- crs(dist);
# Run loop
for (i in 1:length(dist)){
subjName <- as.character(dist#data$Species[i]);
if (!(subjName %in% rangeElevation$?..Species_name)){
paste0(subjName, 'does not exist in the elevational range database.');
}
else{
erNameMatch <- match(subjName, rangeElevation$?..Species_name);
temp <- raster::reclassify(elevation, rcl = c(-Inf,rangeElevation[erNameMatch,2],NA,
rangeElevation[erNameMatch,2],rangeElevation[erNameMatch,3],1,
rangeElevation[erNameMatch,3],Inf,NA));
temp2 <- dist[i,];
temp <- mask(temp, temp2);
temp <- crop(temp, temp2);
temp3 <- rasterToPolygons(temp, na.rm = T, dissolve = T);
names(temp3) <- make.names(names(temp2), unique = T);
temp3#data <- temp2#data;
dist[i,] <- temp3; # <<<< This is the line of code that doesn't work.
}
}

Answer 1

Upon further thought, I came up with a workaround: initiating a list, then using rbind after the loop to unite everything back together into a single object. I'm still interested in finding out why dist[i,] <- temp3 doesn't work, but at least I was able to get this job done.
oneSPDFtoRuleThemAll <- vector(mode = "list", length = length(dist));
for (i in 1:length(dist)){
subjName <- as.character(dist#data$Species[i]);
if (!(subjName %in% rangeElevation$?..Species_name)){
paste0(subjName, 'does not exist in the elevational range database.');
}
else{
erNameMatch <- match(subjName, rangeElevation$?..Species_name);
temp <- raster::reclassify(elevation, rcl = c(-Inf,rangeElevation[erNameMatch,2],NA,
rangeElevation[erNameMatch,2],rangeElevation[erNameMatch,3],1,
rangeElevation[erNameMatch,3],Inf,NA));
temp2 <- dist[i,];
temp <- mask(temp, temp2);
temp <- crop(temp, temp2);
temp3 <- rasterToPolygons(temp, na.rm = T, dissolve = T);
names(temp3) <- make.names(names(temp2), unique = T);
temp3#data <- temp2#data;
oneSPDFtoRuleThemAll[[i]] <- temp3; # <<<< This is the line of code that doesn't work.
}
}
finalSPDF <- rbind(unlist(oneSPDFtoRuleThemAll));