d3.parcoords.js
function selected() {
            var actives = d3.keys(__.dimensions).filter(is_brushed),
                extents = actives.map(function(p) { return brushes[p].extent(); });

            // We don't want to return the full data set when there are no axes brushed.
            // Actually, when there are no axes brushed, by definition, no items are
            // selected. So, let's avoid the filtering and just return false.
            //if (actives.length === 0) return false;

            // Resolves broken examples for now. They expect to get the full dataset back from empty brushes
            if (actives.length === 0) return __.data;

            // test if within range
            var within = {
                "date": function(d,p,dimension) {
                    if (typeof __.dimensions[p].yscale.rangePoints === "function") { // if it is ordinal
                        return extents[dimension][0] <= __.dimensions[p].yscale(d[p]) && __.dimensions[p].yscale(d[p]) <= extents[dimension][1]
                    } else {
                        return extents[dimension][0] <= d[p] && d[p] <= extents[dimension][1]
                    }
                },
                "number": function(d,p,dimension) {
                    if (typeof __.dimensions[p].yscale.rangePoints === "function") { // if it is ordinal
                        return extents[dimension][0] <= __.dimensions[p].yscale(d[p]) && __.dimensions[p].yscale(d[p]) <= extents[dimension][1]
                    } else {
                        return extents[dimension][0] <= d[p] && d[p] <= extents[dimension][1]
                    }
                },
                "string": function(d,p,dimension) {
                    return extents[dimension][0] <= __.dimensions[p].yscale(d[p]) && __.dimensions[p].yscale(d[p]) <= extents[dimension][1]
                }
            };

            return __.data
                .filter(function(d) {
                    switch(brush.predicate) {
                        case "AND":
                            return actives.every(function(p, dimension) {
                                return within[__.dimensions[p].type](d,p,dimension);
                            });
                        case "OR":
                            return actives.some(function(p, dimension) {
                                return within[__.dimensions[p].type](d,p,dimension);
                            });
                        default:
                            throw new Error("Unknown brush predicate " + __.brushPredicate);
                    }
                });
        }
function selected() {
            var actives = d3.keys(__.dimensions).filter(is_brushed),
                extents = actives.map(function(p) { return brushes[p].extent(); });

            // We don't want to return the full data set when there are no axes brushed.
            // Actually, when there are no axes brushed, by definition, no items are
            // selected. So, let's avoid the filtering and just return false.
            //if (actives.length === 0) return false;

            // Resolves broken examples for now. They expect to get the full dataset back from empty brushes
            if (actives.length === 0) return __.data;

            // test if within range
            var within = {
                "date": function(d,p,dimension) {
                    if (typeof __.dimensions[p].yscale.rangePoints === "function") { // if it is ordinal
                        return extents[dimension][0] <= __.dimensions[p].yscale(d[p]) && __.dimensions[p].yscale(d[p]) <= extents[dimension][1]
                    } else {
                        return extents[dimension][0] <= d[p] && d[p] <= extents[dimension][1]
                    }
                },
                "number": function(d,p,dimension) {
                    if (typeof __.dimensions[p].yscale.rangePoints === "function") { // if it is ordinal
                        return extents[dimension][0] <= __.dimensions[p].yscale(d[p]) && __.dimensions[p].yscale(d[p]) <= extents[dimension][1]
                    } else {
                        return extents[dimension][0] <= d[p] && d[p] <= extents[dimension][1]
                    }
                },
                "string": function(d,p,dimension) {
                    return extents[dimension][0] <= __.dimensions[p].yscale(d[p]) && __.dimensions[p].yscale(d[p]) <= extents[dimension][1]
                }
            };

            return __.data
                .filter(function(d) {
                    switch(brush.predicate) {
                        case "AND":
                            return actives.every(function(p, dimension) {
                                return within[__.dimensions[p].type](d,p,dimension);
                            });
                        case "OR":
                            return actives.some(function(p, dimension) {
                                return within[__.dimensions[p].type](d,p,dimension);
                            });
                        default:
                            throw new Error("Unknown brush predicate " + __.brushPredicate);
                    }
                });
        }
data within extents