swapp.ls 23 KB
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442 443 444 445 446 447 448 449 450 451 452 453 454 455 456 457 458 459 460 461 462 463 464 465 466 467 468 469 470 471 472 473 474 475 476 477 478 479 480 481 482 483 484 485 486 487 488 489 490 491 492 493 494 495 496 497 498 499 500 501 502 503 504 505 506 507 508 509 510 511 512 513 514 515 516 517 518 519 520 521 522 523 524 525 526 527 528 529 530 531 532 533 534 535 536 537 538 539 540 541 542 543 544 545 546 547 548 549 550 551 552 553 554 555 556 557 558 559 560 561 562 563 564 565 566 567 568 569 570 571 572 573 574 575 576 577 578 579 580 581 582 583 584 585 586 587 588 589 590 591 592 593 594 595 596 597 598 599 600 601 602 603 604 605 606 607 608 609 610 611 612 613 614 615 616 617 618 619 620 621 622 623 624 625 626 627 628 629 630 631 632 633 634 635 636 637 638 639 640 641 642 643 644 645 646 647 648 649 650 651 652 653 654 655 656 657 658 659 660 661 662 663 664 665 666 667 668 669 670 671 672 673 674 675 676 677 678 679 680 681 682 683 684
# Livescript transpiles to javascript, and is easier on the eyes and brain.
# Get the `lsc` binary from here : http://livescript.net
# It is quite close to Python, syntax-wise, and full of sugar.

# To transpile this file to javascript, and generate `swapp.js` :
# $ lsc --compile swapp.ls
# You can have it watch for changes and transpile automatically :
# $ lsc --watch --compile swapp.ls

# All the "javascript" code is in this file, except for inline scripts in
# templates, such as `home.html.jinja2`.

# Note: We use Promises and ES6 whenever relevant.

###############################################################################

const GOLDEN_RATIO = 2 / (1 + Math.sqrt(5))  # Between 0 and 1 (0.618...)

###############################################################################

class Target
  (@slug, @name, @config) ->
    @active = true  # by default, all targets are active at first

###############################################################################

export class SpaceWeather
  """
  The main app, instanciated from an inline script.
  It defaults to an interval starting a year ago, and ending in seven days.
  (both at midnight)
  """

  (@configuration) ->
    console.info """
  _   _      _ _       ____
 | | | | ___| (_) ___ |  _ \\ _ __ ___  _ __   __ _
 | |_| |/ _ \\ | |/ _ \\| |_) | '__/ _ \\| '_ \\ / _` |
 |  _  |  __/ | | (_) |  __/| | | (_) | |_) | (_| |
 |_| |_|\\___|_|_|\\___/|_|_  |_|_ \\___/| .__/ \\__,_|
 | |__  _   _   / ___|  _ \\|  _ \\|  _ \\_|
 | '_ \\| | | | | |   | | | | |_) | |_) |
 | |_) | |_| | | |___| |_| |  __/|  __/
 |_.__/ \\__, |  \\____|____/|_|   |_|
        |___/

The full source of this website is available at :
https://gitlab.irap.omp.eu/CDPP/SPACEWEATHERONLINE
"""  # HelioPropa by CDPP (mushed 'cause we need to escape backslashes)
    @targets = {}
    configs = [@configuration.targets[k] for k of @configuration.targets]
    configs.forEach((target_config) ~>
      @targets[target_config.slug] = new Target(target_config.slug, target_config.name, target_config)
    )
    @parameters = {}
    @configuration['parameters'].forEach((p) ~>
        @parameters[p['id']] = p
    )

  init: ->
    """
    This is called by the inline bootstrap javascript code.
    This ain't in the constructor because it might return a Promise later on.
    (for the loader, for example)
    """
    active_targets = [ @targets[k] for k of @targets when @targets[k].config.active ]
    @orbits = new Orbits(@configuration.orbits_container, @configuration)
    # Set the h/m/s to zero so that files are cached per whole days
    @started_at = moment().subtract(1, 'years').hours(0).minutes(0).seconds(0)
    @stopped_at = moment().add(7, 'days').hours(0).minutes(0).seconds(0)
    started_at = @started_at.format("YYYY-MM-DDTHH:mm:ss")
    stopped_at = @stopped_at.format("YYYY-MM-DDTHH:mm:ss")
    console.info "Setting time interval from #{started_at} to #{stopped_at}…"
    active_targets.forEach((target) ~>
      console.info "Loading CSV data of #{target.name}…"
      @loadData(target.slug, started_at, stopped_at).then(
        (data) ~>
          console.info "Loaded CSV data of #{target.name}."
          @createTimeSeries(target, data)
          @orbits.initOrbiter(target.slug, target.config, data['hci'])
        ,
        (error) -> console.error('Failed to load CSV data.', error)
      )
    )
    window.addEventListener 'resize', ~> @resize()

  buildDataUrlForTarget: (target_slug, started_at, stopped_at) ->
    url = @configuration['api']['data_for_interval']
    url = url.replace('<target>', target_slug)
    url = url.replace('<started_at>', started_at)
    url = url.replace('<stopped_at>', stopped_at)
    url

  addTarget: (target) ->
    @targets[target.slug] = target
    this

  enableAllTargets: ->
    for slug, target of @targets
      showTarget(slug)
    this

  enableTarget: (target_slug) ->
    timeSeries.forEach((ts) ~> ts.show() if ts.target.slug == target_slug && @parameters[ts.parameter].active)
    @targets[target_slug].active = true
    this

  disableTarget: (target_slug) ->
    timeSeries.forEach((ts) -> ts.hide() if ts.target.slug == target_slug)
    @targets[target_slug].active = false
    this

  resize: ->
    @orbits?.resize();
    timeSeries.forEach((ts) -> ts.resize())

  loadData: (target_slug, started_at, stopped_at) ->
    """
    Load the data as CSV for the specified target and interval,
    and return it in a Promise.
    """
    sw = this
    promise = new Promise((resolve, reject) ->
      url = sw.buildDataUrlForTarget(target_slug, started_at, stopped_at)
      d3.csv(url, (csv) ->
        timeFormat = d3.timeParse('%Y-%m-%dT%H:%M:%S%Z')
        data = {'hci': []};
        configuration['parameters'].forEach((parameter) ->
            data[parameter['id']] = []
        )
        csv.forEach((d) ->
          dtime = timeFormat(d['time'])
          configuration['parameters'].forEach((parameter) ->
            id = parameter['id']
            data[id].push({x: dtime, y: parseFloat(d[id])})
          )
          if (d['xhci'] && d['yhci'])
            data['hci'].push({t: dtime, x: parseFloat(d['xhci']), y: parseFloat(d['yhci'])});
        )
        resolve(data)
      )
    )
    promise

  timeSeries = []  # Not sure why this ain't an instance prop. Probably should.
  createTimeSeries: (target, data) ->
    @configuration['parameters'].forEach((parameter) ~>
      container = @configuration['time_series_container']
      id = parameter['id'] ; title = parameter['title']
      if id not of data then console.error("No data for id '#{id}'.", data)
      timeSeries.push(new TimeSeries(
        id, title, target, data[id], @parameters[id].active, container
      ))
    )
    timeSeries.forEach((ts) ~>
      ts.options['onMouseOver'] = ->
        timeSeries.forEach((ts2) -> ts2.showCursor())
      ts.options['onMouseOut'] = ->
        timeSeries.forEach((ts2) -> ts2.hideCursor())
      ts.options['onMouseMove'] = (t) ~>
        timeSeries.forEach((ts2) -> ts2.moveCursor(t))
        @orbits?.moveToDate(t)
      ts.options['onBrushEnd'] = (sta, sto) ~>
        @resizeDomain(sta, sto)
      ts.options['onDblClick'] = ~>
        @resetZoom()
    )

  enableParameter: (parameter_slug) ->
    if parameter_slug not of @parameters then console.error("Unknown parameter #{parameter_slug}.")
    @parameters[parameter_slug].active = true
    timeSeries.forEach((ts) ~> ts.show() if ts.parameter == parameter_slug && @targets[ts.target.slug].active)
    this

  disableParameter: (parameter_slug) ->
    if parameter_slug not of @parameters then console.error("Unknown parameter #{parameter_slug}.")
    @parameters[parameter_slug].active = false
    timeSeries.forEach((ts) -> ts.hide() if ts.parameter == parameter_slug)
    this

  resizeDomain: (started_at, stopped_at) ->
    if stopped_at < started_at
      tmp = started_at
      started_at = stopped_at
      stopped_at = started_at

    if started_at == stopped_at
      console.warn "Please provide distinct start and stop dates."
      return

    if (@started_at <= started_at <= @stopped_at) and
       (@started_at <= stopped_at <= @stopped_at) then
      console.info "Resizing the temporal domain from #{started_at} to #{stopped_at} without fetching new data…"
      # We first resize the hidden time series and only afterwards we resize
      # the visible ones, for a smoother transition
      timeSeries.forEach((ts) -> if not ts.visible then ts.zoomIn(started_at, stopped_at))
      timeSeries.forEach((ts) -> if     ts.visible then ts.zoomIn(started_at, stopped_at))
      @orbits.resizeDomain started_at, stopped_at
      return

    # todo: fetch new data and remake the plots

  resetZoom: ->
    timeSeries.forEach((ts) -> ts.resetZoom())
    @orbits.resetZoom()



###############################################################################
###############################################################################


export class TimeSeries
  # Time in x-axis
  # Data in y-axis

  (@parameter, @title, @target, data, @visible, @container, @options = {}) ->
    # parameter : slug of the parameter to observe, like magn or pdyn
    # title : string, more descriptive, shown on the left of the Y axis
    # target : target object, like described in configuration
    # data : list of {x: <datetime>, y: <float>}
    @setData(data)
    @init()

  toString: -> "#{@title} of #{@target.name}"

  setData: (data) ->
    @data = data  # and pre-compute extents for performance when zooming
    @xDataExtent = d3.extent(@data, (d) -> d.x)
    @yDataExtent = d3.extent(@data, (d) -> d.y)

  init: ->
    console.info "Initializing plot of #{@}…"

    @margin = {
      top: 30,
      right: 20,
      bottom: 30,
      left: 80
    }

    @xScale = d3.scaleTime().domain(@xDataExtent)
    @yScale = d3.scaleLinear().domain(@yDataExtent)

    @xAxis = d3.axisBottom()
#               .tickFormat(d3.timeFormat("%Y-%m-%d"))
               .ticks(7)
    @yAxis = d3.axisLeft()
               .ticks(10)

    @line = d3.line()
              .x((d) ~> @xScale(d.x))
              .y((d) ~> @yScale(d.y))

    @svg = d3.select(@container).append('svg')
    @svg.attr("class", "#{@parameter} #{@target.slug}")

    @plotWrapper = @svg.append('g')
    @plotWrapper.attr('transform',
                      'translate(' + @margin.left + ',' + @margin.top + ')')

    clipId = "ts-clip-#{@parameter}-#{@target.slug}"
    @clip = @svg.append("defs").append("svg:clipPath")
                .attr("id", clipId)
                .append("svg:rect")
                .attr("x", 0)
                .attr("y", 0)

    @pathWrapper = @plotWrapper.append('g')
    @pathWrapper.attr("clip-path", "url(\##{clipId})")
    @path = @pathWrapper.append('path')
                        .datum(@data)
                        .classed('line', true)

    @brush = @plotWrapper.append("g")
                         .attr("class", "brush")

    # deprecated, use brush's 'overlay' child
    @mouseCanvas = @plotWrapper.append("rect")
                               .style("fill", "none")

    @plotWrapper.append('g').classed('x axis', true)
    @plotWrapper.append('g').classed('y axis', true)
    @yAxisText = @plotWrapper.append("text")
                             .attr("transform", "rotate(-90)")
                             .attr("dy", "1em")
                             .style("text-anchor", "middle")
                             .text(@title)
    @yAxisTextTarget = @plotWrapper.append("text")
                                   .attr("transform", "rotate(-90)")
                                   .attr("dy", "1em")
                                   .style("text-anchor", "middle")
                                   .style("font-style", "oblique")
                                   .text(@target.name)

    @focus = @plotWrapper.append('g').style("display", "none")

    @cursorCircle = @focus.append("circle")
                          .attr("class", "cursor-circle")
                          .attr("r", 3)

    dx = 8
    @cursorValueShadow = @focus.append("text")
                               .attr("class", "cursor-text cursor-text-shadow")
                               .attr("dx", dx)
                               .attr("dy", "-.3em")

    @cursorValue = @focus.append("text")
                         .attr("class", "cursor-text cursor-value")
                         .attr("dx", dx)
                         .attr("dy", "-.3em")

    @cursorDateShadow = @focus.append("text")
                              .attr("class", "cursor-text cursor-text-shadow")
                              .attr("dx", dx)
                              .attr("dy", "1em")

    @cursorDate = @focus.append("text")
                        .attr("class", "cursor-text cursor-date")
                        .attr("dx", dx)
                        .attr("dy", "1em")

    @resize()

  RATIO = GOLDEN_RATIO * GOLDEN_RATIO * GOLDEN_RATIO * GOLDEN_RATIO
  resize: ->
    width  = Math.ceil($(@container).width() - @margin.left - @margin.right)
    height = Math.ceil(RATIO * width)

    @plotWidth = width
    @plotHeight = height

    console.debug("Resizing #{@}: #{width} x #{height}…")

    @xScale.range([0, width]);
    @yScale.range([height, 0]);

    @svg.attr('width',  width + @margin.right + @margin.left)
        .attr('height', height + @margin.top + @margin.bottom)

    @clip.attr("width", width)
         .attr("height", height)

    @path.attr('d', @line)

    @xAxis.scale(@xScale)
    @yAxis.scale(@yScale)

    #if width < 600 then @xAxis.ticks(3) else @xAxis.ticks(7, ",f")
    @xAxis.ticks(Math.floor(width / 90.0))  # not working as expected
    @yAxis.ticks(Math.floor(height / 18.0))

    @svg.select('.x.axis')
        .attr('transform', 'translate(0,' + height + ')')
        .call(@xAxis)

    @svg.select('.y.axis')
        .call(@yAxis)

    @yAxisText.attr("y", 20 - @margin.left)
              .attr("x", 0 - (height / 2))

    @yAxisTextTarget.attr("y", 0 - @margin.left)
                    .attr("x", 0 - (height / 2))

    @mouseCanvas.attr("width", width)
                .attr("height", height)

    if not @brushFunction?
      console.debug "Creating the zooming brush for #{@}…"
      # looks like d3.brush handles its own resizing on window.resize
      @brushFunction =
          d3.brushX()
            .extent([[0, 0], [width, height]])
            .handleSize(0)
            .on("end", @onBrushEnd)
#            .on("start", @onBrushStart)
#            .on("move", @onBrushMove)
      @brush.call(@brushFunction)

      # We're also adding our own cursor events to the brush's overlay,
      # because it captures events and a rect cannot contain another.
      @svg.select(".brush .overlay")
          .on("mouseover.swapp", @onMouseOver)
          .on("mouseout.swapp",  @onMouseOut)
          .on("mousemove.swapp", @onMouseMove)
          .on("dblclick.swapp",  @onDoubleClick)

    unless @visible then @hide()
    this

  show: ->
    $(@svg.node()).show()
    @visible = true

  hide: ->
    $(@svg.node()).hide()
    @visible = false

  onMouseMove: ~>
    x = @xScale.invert(d3.mouse(@mouseCanvas.node())[0])
    if @options.onMouseMove? then @options.onMouseMove(x) else @moveCursor(x)

  onMouseOver: ~>
    if @options.onMouseOver? then @options.onMouseOver() else @showCursor()

  onMouseOut: ~>
    if @options.onMouseOut? then @options.onMouseOut() else @hideCursor()

  onDoubleClick: ~>
    if @options.onDblClick? then @options.onDblClick() else @resetZoom()

  onBrushEnd: ~>
    s = d3.event.selection
    if s
      minmax = [s[0], s[1]].map(@xScale.invert, @xScale)
      @brush.call(@brushFunction.move, null)  # some voodoo to hide the brush
      if @options.onBrushEnd? then @options.onBrushEnd(minmax[0], minmax[1])
                              else @zoomIn(minmax[0], minmax[1])

  zoomIn: (startDate, stopDate) ->
    console.debug "Zooming in #{@} from #{startDate} to #{stopDate}."
    [minDate, maxDate] = @xDataExtent
    if startDate < minDate then startDate = minDate
    if stopDate > maxDate then stopDate = maxDate
    @xScale.domain([startDate, stopDate])
    @applyZoom()

  resetZoom: ->
    @xScale.domain(@xDataExtent)
    @yScale.domain(@yDataExtent)
    @applyZoom()

  applyZoom: ->
    if @visible
      console.debug("Applying zoom to visible #{@}…")
      t = @svg.transition().duration(750)
      @svg.select('.x.axis').transition(t).call(@xAxis);
      @svg.select('.y.axis').transition(t).call(@yAxis);
      @path.transition(t).attr('d', @line)
    else
      console.debug("Applying zoom to hidden #{@}…")
      @svg.select('.x.axis').call(@xAxis);
      @svg.select('.y.axis').call(@yAxis);
      @path.attr('d', @line)

  showCursor: ->
    @focus.style("display", null)

  hideCursor: ->
    @focus.style("display", "none")

  bisectDate: d3.bisector((d) -> d.x).left  # /!\ complex
  timeFormat: d3.timeFormat("%Y-%m-%d %Hh")

  moveCursor: (x0) ->
    i = @bisectDate(@data, x0, 1)
    d0 = @data[i - 1]
    d1 = @data[i]
    return unless d1 and d0
    d = if x0 - d0.x > d1.x - x0 then d1 else d0
    xx = @xScale(d.x)
    yy = @yScale(d.y)

    mirrored = if @plotWidth? and xx > @plotWidth / 2 then true else false

    dx = 8  # horizontal delta between the dot and the text
    dx = -1 * dx if mirrored

    transform = "translate(#{xx}, #{yy})"
    @cursorCircle.attr("transform", transform)
    @cursorValue.attr("transform", transform).text(d.y)
                .attr('text-anchor', if mirrored then 'end' else 'start')
                .attr("dx", dx)
    @cursorValueShadow.attr("transform", transform).text(d.y)
                      .attr('text-anchor', if mirrored then 'end' else 'start')
                      .attr("dx", dx)
    @cursorDate.attr("transform", transform).text(@timeFormat(d.x))
               .attr('text-anchor', if mirrored then 'end' else 'start')
               .attr("dx", dx)
    @cursorDateShadow.attr("transform", transform).text(@timeFormat(d.x))
                     .attr('text-anchor', if mirrored then 'end' else 'start')
                     .attr("dx", dx)

    this


###############################################################################
###############################################################################

export class Orbits
  """
  View of the solar system from above, with orbits segments for selected time
  interval, from real data.
  """

  (@container, @options = {}) ->
    @init()

  init: ->
    console.log "Initializing plot of orbits…"

    @margin = {
      top: 30,
      right: 20,
      bottom: 42,
      left: 60
    }

    @data = {}  # slug => HCI array
    @orbiters = {}  # slug => config
    @extremum = 1
    @xScale = d3.scaleLinear().domain([-1 * @extremum, @extremum])
    @yScale = d3.scaleLinear().domain([-1 * @extremum, @extremum])

    @xAxis = d3.axisBottom().ticks(10)
    @yAxis = d3.axisLeft().ticks(10)

    @svg = d3.select(@container).append('svg')

    @plotWrapper = @svg.append('g')
    @plotWrapper.attr('transform', 'translate(' + @margin.left + ',' + @margin.top + ')')

    @xAxisLine = @plotWrapper.append('g').classed('x axis', true)
    @yAxisLine = @plotWrapper.append('g').classed('y axis', true)

    @xAxisTitle = @xAxisLine.append('text').attr('fill', '#000')
    @xAxisTitle.style("text-anchor", "middle")
    @xAxisTitle.append('tspan').text('X')
    # No : https://bugzilla.mozilla.org/show_bug.cgi?id=308338
    # @xAxisTitle.append('tspan').attr('baseline-shift', 'sub').text('HEE')
    # Also, don't use em as dy units
    @xAxisTitle.append('tspan').attr('dy', '3px').text('HEE').attr('font-size', '8px')
    @xAxisTitle.append('tspan').attr('dy', '-3px').text('   (AU)')

    @yAxisTitle = @yAxisLine.append('text').attr('fill', '#000')
    @yAxisTitle.style("text-anchor", "middle")
    @yAxisTitle.append('tspan').text('Y')
    @yAxisTitle.append('tspan').attr('dy', '3px').text('HEE').attr('font-size', '8px')
    @yAxisTitle.append('tspan').attr('dy', '-3px').text('   (AU)')
    @yAxisTitle.attr('transform', 'rotate(-90)')

    @sun = @plotWrapper.append("svg:image")
                       .attr('xlink:href', @options.sun.img)
                       .attr('width', '32px').attr('height', '32px')
    @sun.append('svg:title').text("Sol")

    $(@svg.node()).hide();  # we'll show it later when there'll be data
    @resize()

  orbitersElements: {}
  initOrbiter: (slug, config, data) ->
    console.info "Initializing orbit of #{config.name}…"
    if slug of @orbitersElements then throw new Error("Second init of #{slug}")

    @extremum = Math.max(@extremum, 1.11 * d3.max(data, (d) ->
      Math.max(Math.abs(d.x), Math.abs(d.y))
    ))
    @xScale = d3.scaleLinear().domain([-1 * @extremum, @extremum])
    @yScale = d3.scaleLinear().domain([-1 * @extremum, @extremum])

    # The order is important, as it will define the default z-order
    orbit_ellipse = @plotWrapper.append("svg:ellipse")
                                .classed('orbit orbit_ellipse', true)
    orbiter = @plotWrapper.append("svg:image")
                          .attr('xlink:href', config['img'])
                          .attr('width', '32px').attr('height', '32px')

    orbit_line = d3.line()
                   .x((d) ~> @xScale(d.x))
                   .y((d) ~> @yScale(d.y))

    orbit_section = @plotWrapper.append('path')
                                .datum(data)
                                .classed('orbit orbit_section', true)

    @orbiters[slug] = config
    @data[slug] = data
    @orbitersElements[slug] =
      orbiter: orbiter
      orbit_ellipse: orbit_ellipse
      orbit_section: orbit_section
      orbit_line: orbit_line

    @resize()

    $(@svg.node()).show();

    this

  resize: ->
    width = Math.ceil($(@container).width() - @margin.left - @margin.right)
    height = Math.ceil(1.0 * width)

    console.debug("Resizing orbits : #{width} × #{height}…")

    @xScale.range([0, width]);
    @yScale.range([height, 0]);

    @svg.attr('width',  width + @margin.right + @margin.left)
        .attr('height', height + @margin.top + @margin.bottom)

    @sun.attr("x", width / 2 - 16).attr("y", height / 2 - 16)

    for slug, config of @orbiters
      @resizeOrbiter(slug, config, width, height)

    @xAxis.scale(@xScale)
    @yAxis.scale(@yScale)

    @svg.select('.x.axis')
        .attr('transform', 'translate(0,' + height + ')')
        .call(@xAxis)

    @svg.select('.y.axis')
        .call(@yAxis)

    @xAxisTitle.attr("x", width / 2)
               .attr("y", 37)
    @yAxisTitle.attr("x", -1 * height / 2)
               .attr("y", -30)

    this

  resizeOrbiter: (slug, config, width, height) ->
    console.debug("Resizing orbit of #{slug}…")

    el = @orbitersElements[slug]
    el['orbit_section'].attr('d', el['orbit_line'])

    a = config['orbit']['a']
    b = config['orbit']['b']
    c = Math.sqrt(a*a - b*b)
    cx = (width / 2) - c
    cy = (height / 2)
    @yScale.range([0, height])
    el['orbit_ellipse'].attr('cx', cx).attr('cy', cy)
        .attr('rx', @xScale(a) - @xScale(0))
        .attr('ry', @yScale(b) - @yScale(0))
#        .attr('transform', 'rotate(66,'+(cx+c)+', '+cy+')')
    @yScale.range([height, 0])

    data = @data[slug]

    el['orbiter'].attr('x', @xScale(data[data.length - 1].x) - 16)
    el['orbiter'].attr('y', @yScale(data[data.length - 1].y) - 16)

    this

  repositionOrbiter: (slug, datum) ->
    data = @data[slug]
    datum ?= data[data.length - 1]
    el = @orbitersElements[slug]
    el['orbiter'].attr('x', @xScale(datum.x) - 16)
    el['orbiter'].attr('y', @yScale(datum.y) - 16)
    this

  bisectDate: d3.bisector((d) -> d.t).left

  moveToDate: (t) ->
    console.warn("Trying to move to an undefined date !") unless t
    for slug, el of @orbitersElements
      data = @data[slug]
      i = @bisectDate(data, t, 1)
      d0 = data[i - 1]
      d1 = data[i]
      continue unless d1 and d0
      d = if t - d0.t > d1.t - t then d1 else d0
      @repositionOrbiter(slug, d)
    this

  resizeDomain: (started_at, stopped_at) ->
    for slug, config of @orbiters
      el = @orbitersElements[slug]
      data = @data[slug].filter (d) -> started_at <= d.t <= stopped_at
      el['orbit_section'].datum(data)
      el['orbit_section'].attr('d', el['orbit_line'])

  resetZoom: ->
    for slug, config of @orbiters
      el = @orbitersElements[slug]
      el['orbit_section'].datum(@data[slug])
      el['orbit_section'].attr('d', el['orbit_line'])