Exemple #1
0
    def _fast_process(self, element, key=None):
        # Project coordinates
        proj = self.p.projection
        if proj == element.crs:
            return element

        h, w = element.interface.shape(element, gridded=True)[:2]
        xs = element.dimension_values(0)
        ys = element.dimension_values(1)
        if isinstance(element, RGB):
            rgb = element.rgb
            array = np.dstack([np.flipud(rgb.dimension_values(d, flat=False))
                               for d in rgb.vdims])
        else:
            array = element.dimension_values(2, flat=False)

        (x0, y0, x1, y1) = element.bounds.lbrt()
        width = int(w) if self.p.width is None else self.p.width
        height = int(h) if self.p.height is None else self.p.height

        bounds = _determine_bounds(xs, ys, element.crs)
        yb = bounds['y']
        resampled = []
        xvalues = []
        for xb in bounds['x']:
            px0, py0, px1, py1 = project_extents((xb[0], yb[0], xb[1], yb[1]), element.crs, proj)
            if len(bounds['x']) > 1:
                xfraction = (xb[1]-xb[0])/(x1-x0)
                fraction_width = int(width*xfraction)
            else:
                fraction_width = width
            xs = np.linspace(px0, px1, fraction_width)
            ys = np.linspace(py0, py1, height)
            cxs, cys = cartesian_product([xs, ys])

            pxs, pys, _ = element.crs.transform_points(proj, np.asarray(cxs), np.asarray(cys)).T
            icxs = (((pxs-x0) / (x1-x0)) * w).astype(int)
            icys = (((pys-y0) / (y1-y0)) * h).astype(int)
            xvalues.append(xs)

            icxs[icxs<0] = 0
            icys[icys<0] = 0
            icxs[icxs>=w] = w-1
            icys[icys>=h] = h-1
            resampled_arr = array[icys, icxs]
            if isinstance(element, RGB):
                nvdims = len(element.vdims)
                resampled_arr = resampled_arr.reshape((fraction_width, height, nvdims)).transpose([1, 0, 2])
            else:
                resampled_arr = resampled_arr.reshape((fraction_width, height)).T
            resampled.append(resampled_arr)
        xs = np.concatenate(xvalues[::-1])
        resampled = np.hstack(resampled[::-1])
        datatypes = [element.interface.datatype, 'xarray', 'grid']
        data = (xs, ys)
        for i in range(len(element.vdims)):
            if resampled.ndim > 2:
                data = data + (resampled[::-1, :, i],)
            else:
                data = data + (resampled,)
        return element.clone(data, crs=proj, bounds=None, datatype=datatypes)
Exemple #2
0
    def _fast_process(self, element, key=None):
        # Project coordinates
        proj = self.p.projection
        if proj == element.crs:
            return element

        h, w = element.interface.shape(element, gridded=True)[:2]
        xs = element.dimension_values(0)
        ys = element.dimension_values(1)
        if isinstance(element, RGB):
            rgb = element.rgb
            array = np.dstack([np.flipud(rgb.dimension_values(d, flat=False))
                               for d in rgb.vdims])
        else:
            array = element.dimension_values(2, flat=False)

        (x0, y0, x1, y1) = element.bounds.lbrt()
        width = int(w) if self.p.width is None else self.p.width
        height = int(h) if self.p.height is None else self.p.height

        bounds = _determine_bounds(xs, ys, element.crs)
        yb = bounds['y']
        resampled = []
        xvalues = []
        for xb in bounds['x']:
            px0, py0, px1, py1 = project_extents((xb[0], yb[0], xb[1], yb[1]), element.crs, proj)
            if len(bounds['x']) > 1:
                xfraction = (xb[1]-xb[0])/(x1-x0)
                fraction_width = int(width*xfraction)
            else:
                fraction_width = width
            xs = np.linspace(px0, px1, fraction_width)
            ys = np.linspace(py0, py1, height)
            cxs, cys = cartesian_product([xs, ys])

            pxs, pys, _ = element.crs.transform_points(proj, np.asarray(cxs), np.asarray(cys)).T
            icxs = (((pxs-x0) / (x1-x0)) * w).astype(int)
            icys = (((pys-y0) / (y1-y0)) * h).astype(int)
            xvalues.append(xs)

            icxs[icxs<0] = 0
            icys[icys<0] = 0
            icxs[icxs>=w] = w-1
            icys[icys>=h] = h-1
            resampled_arr = array[icys, icxs]
            if isinstance(element, RGB):
                nvdims = len(element.vdims)
                resampled_arr = resampled_arr.reshape((fraction_width, height, nvdims)).transpose([1, 0, 2])
            else:
                resampled_arr = resampled_arr.reshape((fraction_width, height)).T
            resampled.append(resampled_arr)
        xs = np.concatenate(xvalues[::-1])
        resampled = np.hstack(resampled[::-1])
        datatypes = [element.interface.datatype, 'xarray', 'grid']
        data = (xs, ys)
        for i in range(len(element.vdims)):
            if resampled.ndim > 2:
                data = data + (resampled[::-1, :, i],)
            else:
                data = data + (resampled,)
        return element.clone(data, crs=proj, bounds=None, datatype=datatypes)