keep cutting away

[dygraphs.git] / plotkit_v091 / PlotKit / Layout.js

/* 
    PlotKit Layout
    ==============
    
    Handles laying out data on to a virtual canvas square canvas between 0.0 
    and 1.0. If you want to add new chart/plot types such as point plots,
    you need to add them here.
    
    Copyright
    ---------
    Copyright 2005,2006 (c) Alastair Tse <alastair^liquidx.net>
    For use under the BSD license. <http://www.liquidx.net/plotkit>
    
*/

try {    
    if (typeof(PlotKit.Base) == 'undefined')
    {
        throw ""
    }
} 
catch (e) {    
    throw "PlotKit.Layout depends on MochiKit.{Base,Color,DOM,Format} and PlotKit.Base"
}

// --------------------------------------------------------------------
// Start of Layout definition
// --------------------------------------------------------------------

if (typeof(PlotKit.Layout) == 'undefined') {
    PlotKit.Layout = {};
}

PlotKit.Layout.NAME = "PlotKit.Layout";
PlotKit.Layout.VERSION = PlotKit.VERSION;

PlotKit.Layout.__repr__ = function() {
    return "[" + this.NAME + " " + this.VERSION + "]";
};

PlotKit.Layout.toString = function() {
    return this.__repr__();
}

// --------------------------------------------------------------------
// Start of Layout definition
// --------------------------------------------------------------------

PlotKit.Layout = function(style, options) {
  
    this.options = {
        "xOriginIsZero": true,
        "yOriginIsZero": true,
        "xAxis": null, // [xmin, xmax]
        "yAxis": null, // [ymin, ymax]
        "xTicks": null, // [{label: "somelabel", v: value}, ..] (label opt.)
        "yTicks": null, // [{label: "somelabel", v: value}, ..] (label opt.)
    };

    // valid external options : TODO: input verification
    this.style = style; 
    MochiKit.Base.update(this.options, options ? options : {});

    this.minxval = 0;
    this.maxxval = null;
    this.xscale = null; // val -> pos factor (eg, xval * xscale = xpos)

    this.minyval = 0;
    this.maxyval = null;
    this.yscale = null;

    this.points = new Array(); // array of points to plot for line plots

    this.xticks = new Array();
    this.yticks = new Array();

    // internal states
    this.datasets = new Array();
    this.minxdelta = 0;
    this.xrange = 1;
    this.yrange = 1;
};

// --------------------------------------------------------------------
// Dataset Manipulation
// --------------------------------------------------------------------


PlotKit.Layout.prototype.addDataset = function(setname, set_xy) {
    this.datasets[setname] = set_xy;
};

// --------------------------------------------------------------------
// Evaluates the layout for the current data and style.
// --------------------------------------------------------------------

PlotKit.Layout.prototype.evaluate = function() {
    this._evaluateLimits();
    this._evaluateLineCharts();
    this._evaluateLineTicks();
};


// --------------------------------------------------------------------
// START Internal Functions
// --------------------------------------------------------------------

PlotKit.Layout.prototype._evaluateLimits = function() {
    // take all values from all datasets and find max and min
    var map = PlotKit.Base.map;
    var items = PlotKit.Base.items;
    var itemgetter = MochiKit.Base.itemgetter;
    var collapse = PlotKit.Base.collapse;
    var listMin = MochiKit.Base.listMin;
    var listMax = MochiKit.Base.listMax;
    var isNil = MochiKit.Base.isUndefinedOrNull;

    var all = collapse(map(itemgetter(1), items(this.datasets)));
    this.minxval = listMin(map(parseFloat, map(itemgetter(0), all)));
    this.maxxval = listMax(map(parseFloat, map(itemgetter(0), all)));
    this.xrange = this.maxxval - this.minxval;
    this.xscale = (this.xrange != 0 ? 1/this.xrange : 1.0);

    this.minyval = this.options.yAxis[0];
    this.maxyval = this.options.yAxis[1];
    this.yrange = this.maxyval - this.minyval;
    this.yscale = (this.yrange != 0 ? 1/this.yrange : 1.0);
};

// Create the line charts
PlotKit.Layout.prototype._evaluateLineCharts = function() {
    var items = PlotKit.Base.items;

    var setCount = items(this.datasets).length;

    // add all the rects
    this.points = new Array();
    var i = 0;
    for (var setName in this.datasets) {
        var dataset = this.datasets[setName];
        if (PlotKit.Base.isFuncLike(dataset)) continue;
        dataset.sort(function(a, b) { return compare(parseFloat(a[0]), parseFloat(b[0])); });
        for (var j = 0; j < dataset.length; j++) {
            var item = dataset[j];
            var point = {
                x: ((parseFloat(item[0]) - this.minxval) * this.xscale),
                y: 1.0 - ((parseFloat(item[1]) - this.minyval) * this.yscale),
                xval: parseFloat(item[0]),
                yval: parseFloat(item[1]),
                name: setName
            };

            // limit the x, y values so they do not overdraw
            if (point.y <= 0.0) {
                point.y = 0.0;
            }
            if (point.y >= 1.0) {
                point.y = 1.0;
            }
            if ((point.x >= 0.0) && (point.x <= 1.0)) {
                this.points.push(point);
            }
        }
        i++;
    }
};


PlotKit.Layout.prototype._evaluateLineTicksForXAxis = function() {
    var isNil = MochiKit.Base.isUndefinedOrNull;
    
    this.xticks = new Array();
    var makeTicks = function(tick) {
        var label = tick.label;
        if (isNil(label))
            label = tick.v.toString();
        var pos = this.xscale * (tick.v - this.minxval);
        if ((pos >= 0.0) && (pos <= 1.0)) {
            this.xticks.push([pos, label]);
        }
    };
    MochiKit.Iter.forEach(this.options.xTicks, bind(makeTicks, this));
};

PlotKit.Layout.prototype._evaluateLineTicksForYAxis = function() {
    var isNil = MochiKit.Base.isUndefinedOrNull;

    this.yticks = new Array();
    var makeTicks = function(tick) {
        var label = tick.label;
        if (isNil(label))
            label = tick.v.toString();
        var pos = 1.0 - (this.yscale * (tick.v - this.minyval));
        if ((pos >= 0.0) && (pos <= 1.0)) {
            this.yticks.push([pos, label]);
        }
    };
    MochiKit.Iter.forEach(this.options.yTicks, bind(makeTicks, this));
};

PlotKit.Layout.prototype._evaluateLineTicks = function() {
    this._evaluateLineTicksForXAxis();
    this._evaluateLineTicksForYAxis();
};


// --------------------------------------------------------------------
// END Internal Functions
// --------------------------------------------------------------------


// Namespace Iniitialisation

PlotKit.LayoutModule = {};
PlotKit.LayoutModule.Layout = PlotKit.Layout;

PlotKit.LayoutModule.EXPORT = [
    "Layout"
];

PlotKit.LayoutModule.EXPORT_OK = [];

PlotKit.LayoutModule.__new__ = function() {
    var m = MochiKit.Base;
    
    m.nameFunctions(this);
    
    this.EXPORT_TAGS = {
        ":common": this.EXPORT,
        ":all": m.concat(this.EXPORT, this.EXPORT_OK)
    };
};

PlotKit.LayoutModule.__new__();
MochiKit.Base._exportSymbols(this, PlotKit.LayoutModule);