I want to update my bar chart when the value of the chart get changes.
I get data for the chart from restful services.
I don't want to delete an entire chart and then redraw; instead I wanted to update the existing bar values with the new values.
1.Each and Every time the number of rows is getting changed when i get input from webservice for dataset.
2.I Can manage to update the bars height value when the number of rows is equal.But it contain more number of rows than before i have the problem facing unexpected output.
I submitted the sample code.//i just use this code from stack overflow site.
function mf(){
data = d3.range(10).map(next);
var rect= chart.selectAll("rect")
.data(data)
.attr("x", function(d, i) { return x(i) - .5; })
.attr("y", function(d) { return h - y(d.value) - .5; })
.attr("width", w)
.attr("height", function(d) { return y(d.value); });
rect.enter()
.append("svg:rect")
.attr("x", function(d, i) { return x(i) - .5; })
.attr("y", function(d) { return h - y(d.value) - .5; })
.attr("width", w)
.attr("height", function(d) { return y(d.value); });
rect.exit().remove();
}
Related
I am able to update my chart by selecting and updating individual attributes but not through enter, update, exit.
This code seems to work just fine:
var chart = d3.select(svg).select("svg");
chart.selectAll("rect").data(data)
.attr("x", function(d, i) {
return i*bar_width;
})
.attr("y", function(d) {
return height - Math.abs(y(d) / 2) - height / 2 + 2;
})
.attr("height", function(d) {
return Math.abs(y(d));
})
.attr("width", bar_width);
However, the below code (where I use enter, update, exit) does not work:
var chart = d3.select(svg).select("svg");
chart.selectAll("rect").data(data)
.enter().append("rect") //Enter
.attr("x", function(d, i) { //Update
return i*bar_width;
})
.attr("y", function(d) {
return height - Math.abs(y(d) / 2) - height / 2 + 2;
})
.attr("height", function(d) {
return Math.abs(y(d));
})
.attr("width", bar_width);
chart.selectAll("rect").exit().remove(); //Remove
I wonder why? FYI: I am using d3 v5.
http://bl.ocks.org/d3noob/8952219
I want to have bar size width to be fixed..
from above example i have changed the code from
svg.selectAll("bar")
.data(data)
.enter().append("rect")
.style("fill", "steelblue")
.attr("x", function(d) { return x(d.date); })
.attr("width", x.rangeBand())
.attr("y", function(d) { return y(d.value); })
.attr("height", function(d) { return height - y(d.value); });
to
svg.selectAll("bar")
.data(data)
.enter().append("rect")
.style("fill", "steelblue")
.attr("x", function(d) { return x(d.date); })
.attr("width", 50)
.attr("y", function(d) { return y(d.value); })
.attr("height", function(d) { return height - y(d.value); });
but the labels are not moving to proper place also bars are getting overlapped
You have to change the range() of your x scale, to fit with your bar width value:
var x = d3.scale.ordinal().rangeRoundBands([0, width], .05);
to (if you want 50px as bar width)
var x = d3.scale.ordinal().range([0, data.length * 50]);
The range() method is used to define the display space for your scale.
I was looking for a similar solution. What #JulCh gave as an answer did not work out of the box for me, but lead me in the right direction.
Try:
var x = d3.scale.ordinal()
.range(d3.range(data.length).map(function (d) { return d * 50; }));
Where the inner d3.range creates an array containing the number of elements determined by data.length or some constant number (the number of bars you would like displayed).
Example: If data.length or some constant is 8 then [0,1,2,3,4,5,6,7] is returned from d3.range(8)
The map function then multiplies your fixed width of 50 against each element in the array returning [0,50,100,150,200,250,300,350].
D3 will then use these exact values to place your bars.
I have a bar chart, which I am using transitions to animate the heights of rect elements like so:
//Create a layer for each category of data that exists, as per dataPointLegend values
//e.g. DOM will render <g class="successful"><g>
layers = svg.selectAll('g.layer')
.data(stacked, function(d) {
return d.dataPointLegend;
})
.enter()
.append('g')
.attr('class', function(d) {
return d.dataPointLegend;
})
//transform below is used to shift the entire layer up by one pixel to allow
//x-axis to appear clearly, otherwise bars inside layer appear over the top.
.attr('transform', 'translate(0,-1)');
//Create a layer for each datapoint object
//DOM will render <g class="successful"><g></g><g>
barLayers = layers.selectAll('g.layer')
.data(function(d) {
return d.dataPointValues;
})
.enter()
.append('g');
//Create rect elements inside each of our data point layers
//DOM will render <g class="successful"><g><rect></rect></g></g>
barLayers
.append('rect')
.attr('x', function(d) {
return x(d.pointKey);
})
.attr('width', x.rangeBand())
.attr('y', height - margin.bottom - margin.top)
.attr('height', 0)
.transition()
.delay(function(d, i) {
return i * transitionDelayMs;
})
.duration(transitionDurationMs)
.attr('y', function(d) {
return y(d.y0 + d.pointValue);
})
.attr('height', function(d) {
return height - margin.bottom - margin.top - y(d.pointValue)
});
I then have a further selection used for appending text elements
//Render any point labels if present
//DOM will render <g><g><rect></rect><text></text></g></g>
if (width > miniChartWidth) {
barLayers
.append('text')
.text(function(d) {
return d.pointLabel
})
.attr('x', function(d) {
return x(d.pointKey) + x.rangeBand() / 2;
})
.attr('y', function(d) {
var textHeight = d3.select(this).node().getBoundingClientRect().height;
//Position the text so it appears below the top edge of the corresponding data bar
return y(d.y0 + d.pointValue) + textHeight;
})
.attr('class', 'data-value')
.attr('fill-opacity', 0)
.transition()
.delay(function(d, i) {
return i * transitionDelayMs + transitionDurationMs;
})
.duration(transitionDurationMs)
.attr('fill-opacity', 1);
}
This fades in the text elements nicely after all the rects have finished growing in height. What I wondered, was whether its possible to append a text element to the corresponding layer as each bar finishes its transition?
I have seen the answer on this SO - Show text only after transition is complete d3.js
Which looks to be along the lines of what I am after, I tried adding an .each('end',...) in my rect rendering cycle like so
.each('end', function(d){
barLayers
.append('text')
.text(function() {
return d.pointLabel
})
.attr('x', function() {
return x(d.pointKey) + x.rangeBand() / 2;
})
.attr('y', function() {
var textHeight = d3.select(this).node().getBoundingClientRect().height;
//Position the text so it appears below the top edge of the corresponding data bar
return y(d.y0 + d.pointValue) + textHeight;
})
.attr('class', 'data-value')
.attr('fill-opacity', 0)
.transition()
.delay(function(d, i) {
return i * transitionDelayMs + transitionDurationMs;
})
.duration(transitionDurationMs)
.attr('fill-opacity', 1);
});
But I end up with lots of text elements for each of my g that holds a single rect for each of my datapoints.
I feel like I'm close, but need some assistance from you wise people :)
Thanks
whateverTheSelectionIs
.each('end', function(d){
barLayers
.append('text')
.each runs separately for every element in your selection, and inside the each you're adding text elements to every barLayer (barLayers). So you're going to get a (barLayers.size() * selection.size()) number of text elements added overall. You need to add only one text element in the each to the right bar / g.
The below is a fudge that might work. It's tricky because the text you want to add is a sibling of the rects in the selection that calls the .each function..., d3.select(this.parentNode) should move you up to the parent of the rect, which would be the right barLayer.
whateverTheSelectionIs
.each('end', function(d,i){
d3.select(this.parentNode)
.append('text')
I'm trying to add some space/padding for a nvd3 multi bar chart. "groupSpacing" is not what I need, since it only adds space between groups. I'll need space between each bar inside group. I found one link in github support. Can you post any solution or tweak?
I also found a d3 example of grouped bar chart. Any help in this example also very helpful to me.
Thanks.
I have draw a d3 group barchart:
fiddle
You can adjust the groupSpacing by change the code on line 56:
var groupSpacing = 6;
Technically i just achieve it by change the width of each rects' width:
var barsEnter = bars.enter().append('rect')
.attr('class', 'stm-d3-bar')
.attr('x', function(d,i,j) {
return (j * x1.rangeBand() );
})
.attr('y', function(d) { return y(d.y); })
.attr('height', function(d) { return height - y(d.y); })
.attr('width', x0.rangeBand() / barData.length - groupSpacing )
.attr('transform', function(d,i) {
return 'translate(' + x0(d.x) + ',0)';
})
.style("fill", function(d, i, j) {
return color(data[j].key);
});
Hope it helps you understand how you can achieve it in d3.
I minus the number of group spacing from the "width" attribute also. I found that the x-axis label looks a little off after I did that so I add the (group spacing / 2) to the "x" attribute. Here is the example of my code.
var groupSpacing = 15;
var rect = groups.selectAll("rect")
.data(function (d) { return d; })
.enter()
.append("rect")
.attr("x", function (d) { return x(d.x) + (groupSpacing / 2) ; })
.attr("y", function (d) { return y(d.y0 + d.y); })
.attr("height", function (d) { return y(d.y0) - y(d.y0 + d.y); })
.attr("width", x.rangeBand() - groupSpacing)
So that I can transition the bars in a bar chart smoothly I need to set the height before I call transition().
When the chart first renders the bars animate up from the bottom of the chart as required:
chart.svg.selectAll('.bar')
.attr('y', chart.options.height)
.attr('x', function (d) {
return chart.xScale(d.title);
})
.attr('width', chart.xScale.rangeBand())
.attr('height', function () {
return 0;
})
.transition()
.attr('y', function (d) {
return chart.yScale(d.score);
})
.attr('height', function (d) {
return chart.options.height - chart.yScale(d.score);
});
However, when I change the data I don't want to set the height back to 0. Instead I need to set the height to the current height of the rectangle. How can I access this from the attr function?
.attr('height', function () {
return 0; // how do I get the current height
})
When I log this I have access to the DOM element but not sure where to go from there. I tried d3.select(this).attr('height') but it always returns null.
As #LarsKotthoff is hinting at in his comment, just break apart your initial draw from your update:
// intial draw of bars
node
.enter()
.append("rect")
.attr("class", "myBars")
.style("fill", "steelblue")
.attr('y', config.height)
.attr('x', function(d, i) {
return xScale(i);
})
.attr('width', xScale.rangeBand())
.attr('height', function() {
return 0;
});
Then fire the update to transition the bars from their current position:
function update() {
node = svg
.selectAll(".myBars")
.data(data);
node
.transition()
.attr('y', function(d) {
return yScale(d);
})
.attr("height", function(d) {
return config.height - yScale(d);
});
}
Here's the most minimal example I could code up.