d3.js parallel coordinate with one different scale - d3.js

Question

I'm trying to generate a parallel coordinate using d3.js
My problem is that the first scale should display different strings.
with the original code it looks like this:
and with my test it looks like this (no lines):
the error code is:
Error: Invalid value for attribute d="M33,NaNL99,161.37817638266068L165,6.543121881682145L231,16.962488563586458L297,180"
here is my code:
function parallelChart (id, size) {
if(size == 'small') {
var margin = {top: 20, right: 80, bottom: 30, left: 50},
width = 460 - margin.left - margin.right,
height = 230 - margin.top - margin.bottom;
} else {
var margin = {top: 20, right: 80, bottom: 30, left: 50},
width = 960 - margin.left - margin.right,
height = 500 - margin.top - margin.bottom;
}
var x = d3.scale.ordinal().rangePoints([0, width], 1),
y = {},
dragging = {};
var line = d3.svg.line(),
axis = d3.svg.axis().orient("left"),
background,
foreground;
var svg = d3.select(id).append("svg")
.attr("class", 'center-block')
.attr("width", width + margin.left + margin.right)
.attr("height", height + margin.top + margin.bottom)
.append("g")
.attr("transform", "translate(" + margin.left + "," + margin.top + ")");
// Original
d3.csv("dataNew.csv", function(error, healthdata) {
x.domain(dimensions = d3.keys(healthdata[0]).filter(function(d) {
return d != "Datum" && (y[d] = d3.scale.linear()
.domain(d3.extent(healthdata, function(p) { return +p[d]; }))
.range([height, 0]));
}));
// this did not work
// d3.csv("dataNew.csv", function(error, healthdata) {
// x.domain(dimensions = d3.keys(healthdata[0]).filter(function(d) {
// if(d == "Datum") {
// return d == "Datum" && ( (y[d] = d3.time.scale()
// .domain(d3.extent(healthdata, function(p) { return +p[d]; }))
// .range([height, 0])));
// }
// return d != "Datum" && ( (y[d] = d3.scale.linear()
// .domain(d3.extent(healthdata, function(p) { return +p[d]; }))
// .range([height, 0])));
// }));
// Add grey background lines for context.
background = svg.append("g")
.attr("class", "background")
.selectAll("path")
.data(healthdata)
.enter().append("path")
.attr("d", path);
// Add blue foreground lines for focus.
foreground = svg.append("g")
.attr("class", "foreground")
.selectAll("path")
.data(healthdata)
.enter().append("path")
.attr("d", path);
// Add a group element for each dimension.
var g = svg.selectAll(".dimension")
.data(dimensions)
.enter().append("g")
.attr("class", "dimension")
.attr("transform", function(d) { return "translate(" + x(d) + ")"; })
.call(d3.behavior.drag()
.origin(function(d) { return {x: x(d)}; })
.on("dragstart", function(d) {
dragging[d] = x(d);
background.attr("visibility", "hidden");
})
.on("drag", function(d) {
dragging[d] = Math.min(width, Math.max(0, d3.event.x));
foreground.attr("d", path);
dimensions.sort(function(a, b) { return position(a) - position(b); });
x.domain(dimensions);
g.attr("transform", function(d) { return "translate(" + position(d) + ")"; })
})
.on("dragend", function(d) {
delete dragging[d];
transition(d3.select(this)).attr("transform", "translate(" + x(d) + ")");
transition(foreground).attr("d", path);
background
.attr("d", path)
.transition()
.delay(500)
.duration(0)
.attr("visibility", null);
}));
// Add an axis and title.
g.append("g")
.attr("class", "axis")
.each(function(d) { d3.select(this).call(axis.scale(y[d])); })
.append("text")
.style("text-anchor", "middle")
.attr("y", -9)
.text(function(d) { return d; });
// Add and store a brush for each axis.
g.append("g")
.attr("class", "brush")
.each(function(d) {
d3.select(this).call(y[d].brush = d3.svg.brush().y(y[d]).on("brushstart", brushstart).on("brush", brush));
})
.selectAll("rect")
.attr("x", -8)
.attr("width", 16);
});
function position(d) {
var v = dragging[d];
return v == null ? x(d) : v;
}
function transition(g) {
return g.transition().duration(500);
}
// Returns the path for a given data point.
function path(d) {
return line(dimensions.map(function(p) { return [position(p), y[p](d[p])]; }));
}
function brushstart() {
d3.event.sourceEvent.stopPropagation();
}
// Handles a brush event, toggling the display of foreground lines.
function brush() {
var actives = dimensions.filter(function(p) { return !y[p].brush.empty(); }),
extents = actives.map(function(p) { return y[p].brush.extent(); });
foreground.style("display", function(d) {
return actives.every(function(p, i) {
return extents[i][0] <= d[p] && d[p] <= extents[i][1];
}) ? null : "none";
});
}
}

Answer 1

Here goes one example where the author manage string and numbers in the same parallel coord:
http://bl.ocks.org/syntagmatic/4020926
Create an array of dimensions that will be further used...
var dimensions = [
{
name: "name",
scale: d3.scale.ordinal().rangePoints([0, height]),
type: "string"
},
{
name: "economy (mpg)",
scale: d3.scale.linear().range([0, height]),
type: "number"
},
...
]
...before load the data, define the domains by mapping your previous dimensions definition...
var x = d3.scale.ordinal()
.domain(dimensions.map(function(d) { return d.name; }))
.rangePoints([0, width]);
...define a variable dimension (pay attention, dimensions != dimension) with the locations of each axis...
var dimension = svg.selectAll(".dimension")
.data(dimensions)
.enter().append("g")
.attr("class", "dimension")
.attr("transform", function(d) { return "translate(" + x(d.name) + ")"; });
...once the data is loaded, execute a for each to define the domain of each dimension...
d3.csv("cars.small.csv", function(data) {
dimensions.forEach(function(dimension) {
dimension.scale.domain(dimension.type === "number"
? d3.extent(data, function(d) { return +d[dimension.name]; })
: data.map(function(d) { return d[dimension.name]; }).sort());
});
...
}
... axis lines and foreground are still loaded in the same way...
svg.append("g")
.attr("class", "background")
.selectAll("path")
.data(data)
.enter().append("path")
.attr("d", draw);
svg.append("g")
.attr("class", "foreground")
.selectAll("path")
.data(data)
.enter().append("path")
.attr("d", draw);
... this code will load the text of each axis, observe that it is now using properties from the dimensions that we defined in the beggining.
dimension.append("g")
.attr("class", "axis")
.each(function(d) { d3.select(this).call(yAxis.scale(d.scale)); })
.append("text")
.attr("class", "title")
.attr("text-anchor", "middle")
.attr("y", -9)
.text(function(d) { return d.name; });
that`s all =).