Examples with Operation org.opengis.coverage.processing.Operation used on opensource projects

Example 1 with Operation

use of org.opengis.coverage.processing.Operation in project structr by structr.

the class GetWCSHistogramFunction method apply.

@Override
public Object apply(final ActionContext ctx, final Object caller, final Object[] sources) throws FrameworkException {
    try {
        assertArrayHasMinLengthAndTypes(sources, 3, String.class, String.class, Geometry.class, Number.class, Number.class, Number.class);
        final String baseUrl = (String) sources[0];
        final String coverageId = (String) sources[1];
        final Geometry geometry = (Geometry) sources[2];
        final GridCoverage2D coverage = getWCSCoverage(baseUrl, coverageId, geometry);
        final CoverageProcessor processor = CoverageProcessor.getInstance();
        final Operation operation = processor.getOperation("Histogram");
        final ParameterValueGroup params = operation.getParameters();
        final int numBins = sources.length > 3 ? parseInt(sources[3], 256) : 256;
        final double lowValue = sources.length > 4 ? parseDouble(sources[4], 0.0) : 0.0;
        final double cutoffPercentage = sources.length > 5 ? parseDouble(sources[5], 0.005) : 0.005;
        final double[] extrema = getExtrema(coverage, 0);
        params.parameter("source0").setValue(coverage);
        params.parameter("numBins").setValue(new int[] { numBins });
        params.parameter("lowValue").setValue(new double[] { lowValue });
        params.parameter("highValue").setValue(new double[] { extrema[1] });
        final NumberFormat format = new DecimalFormat("#,###,##0.00");
        final GridCoverage2D result = (GridCoverage2D) processor.doOperation(params);
        final Histogram histogram = (Histogram) result.getProperty("histogram");
        final int[] bins = histogram.getBins(0);
        final Double binWidth = histogram.getHighValue()[0] / (double) numBins;
        final Map<String, Object> map = new LinkedHashMap<>();
        List<String> binNames = new LinkedList<>();
        List<Integer> binData = new LinkedList<>();
        int lastIndex = 0;
        int restBin = 0;
        double maxCount = 0;
        for (int i = 0; i < bins.length; i++) {
            final double d = i;
            binNames.add(format.format(binWidth * d));
            binData.add(bins[i]);
            if (bins[i] > maxCount) {
                maxCount = bins[i];
            }
        }
        // combine all bins whose value is below a given threshold (maxCount * cutoffPercentage)
        int threshold = Double.valueOf(maxCount * cutoffPercentage).intValue();
        for (int i = 0; i < bins.length; i++) {
            // find index of last bin with more than x elements
            if (bins[i] > threshold) {
                lastIndex = i;
            }
        }
        // collect the sum of all the bins below the threshold
        for (int i = lastIndex; i < bins.length; i++) {
            restBin += bins[i];
        }
        binNames = binNames.subList(0, lastIndex);
        binData = binData.subList(0, lastIndex);
        // add a single bin with all the rest
        binNames.add("> " + format.format(binWidth * lastIndex));
        binData.add(restBin);
        // remove all bins that have less than threshold elements
        map.put("names", binNames);
        map.put("bins", binData);
        return map;
    } catch (ArgumentNullException pe) {
        // silently ignore null arguments
        return "";
    } catch (ArgumentCountException pe) {
        logParameterError(caller, sources, pe.getMessage(), ctx.isJavaScriptContext());
        return usage(ctx.isJavaScriptContext());
    } catch (ArgumentTypeException te) {
        logParameterError(caller, sources, te.getMessage(), ctx.isJavaScriptContext());
        return usage(ctx.isJavaScriptContext());
    }
}