My app is fetching some market live data from a web service and displaying them on a chart.
On the X axis I would have time of an event. The problem is I can have several results from the same moment or within one second, or I can have gaps there - so it's not the case that I can have a set number of x points and for each one of them - a single point on my chart. Also points on the chart won't be distributed equally on against the X axis.
I'm also looking for something that could be updated as the data flows in - including the scaling of the X and Y axis. It would be perfect if I could scroll and zoom in/out (like on a UIScrollView) the whole chart.
Is there a ready-made solution for such a case? Preferably one that allows for some good customization of its looks? I'm wondering if ios-charts could help in that?
For you first question, ios-charts does not support well for the time-style x axis, if the time range spans widely. ios-charts distribute equally for each value on x axis, so to reflect the real time-style axis, you have to generate many x values as each second/hour/day etc, but you don't add any y value for these x values.
for the second question, ios-chats can update the chart by moveViewToX, but the animation couterpart is not implemented yet. ios-charts one great feature is it supports zoom/scale for axis-based charts (excluding pie chart, radar chart). The zoom/scale is implemented via CG.
For other potential charts, if you can use swift, then there is SwiftChart, CorePlot (seems a little old) on github, and Shinobi Chart (not free)
I guess you could give a try with ios-charts, search/open issues to see if anything you needed is carried out.
Related
I'm building a Radar Chart using Google Sheets.
However it insists in not centering in zero and I can't tell what crazy scale it is using in the horizontal axis. Does anyone know if there is a way to center both axis in zero? I tried many different parameters in the chart edition box but couldn't find the right one.
Example sheet here
since you are using percentages you can "round it" like this:
In Vaadin 14.6.1, I tried to create a Vaadin heatmap foollowing the documentation / example from here.
However, I encountered a few problems/questions, listed in descending order of importance below:
The heatmap supported 30 rows by 30 columns; but when I tried 40 rows by 40 columns, the entire heatmap showed a single color (blue in my case).
Is it possible to manually set the minimum numeric value and maximum numeric value for the color scheme. This way, if I plot my data one day and it has values in the range of 0 to 1, but on another dataset from another day, the numeric values range from between 0 and 0.5, the color scheme range won't automatically change (to being between 0 and 0.5) and confuse the user.
In the documentation, it has the following methods listed, but they do not seem to exist in Vaadin 14.6.1
plotOptions.setBorderColor(SolidColor.WHITE);
plotOptions.setBorderWidth(2);
When I hover over the datapoints, is there a way that the tooltip can only show the numeric value (and not the x, y coordinate or the series name etc.?)
Is there any limit to the number of datapoints? I'm hoping that if #1 above is resolved that I can plot a 100 by 100 (ie 10,000) point heatmap.
If I plot 100by100, there will be many labels on the x and y axis. In my case, the x and y axis are actually numerical, so I did what the documentation suggested and just placed category labels in the xaxis and yaxis spots. However, is there any way to only display every "nth" label, so that the x-axis and y-axis is not so crowded? (This would essentially mimic what Vaadin does for normal line charts' xaxis and yaxis).
I'm not that experienced with Vaadin Chart, but these are the questions that I can comment on:
(1) With 40x40 items you go over the threshold of 1000 in which the Chart switches into "turbo" mode for performance reasons. This seems to not be compatible with the heatmap series. You can disable turbo mode by setting plotOptions.setTurboThreshold(0);
(2) Unfortunately the ColorAxis doesn't support this, it only has an API for min and max color. Definitely a valid use-case though, and it seems to be supported by the Highcharts library that the Vaadin Chart uses under the hood. You should consider opening a feature request for this in the Github repo.
(3) This seems to be a documentation issue. The methods are available in later Vaadin platform versions, but not in 14.6.
(5) In theory not, but in practice there will be a huge performance hit in the browser due to the excessive amount of DOM elements (quick test of 100x100 froze the browser for 10s). I'm afraid the component isn't really made for such extreme use-cases. In this case it might be better to utilize a low-level JS drawing library using the canvas, or draw an image on the server-side and display that in the browser. Maybe you can also consider modifying your use-case so that you only display one slice of your data and allow the user to switch between slices.
I am using ios-charts library to draw charts on a swift2 app. I am wondering if, for a given X value, I can change its Y associated value by a drag and drop gesture on the chart.
If this is not possible on this library, is it possible to do such a thing using another library?
technically you can. Every time you scroll/zoom the chart, it will trigger a redraw, so everything is redrawing, you can decide your own logic how you want the y axis value changed.
It has two parts:
In computeAxisValues in y axis renderer, the y axis labels(values) are determined. Then in renderAxisLabels, it is drawn using the calculated values.
So you can take a look at these functions and implement your logic. Note, it's your responsibility to make sure what you are doing is valid in your scenario, because if something weird happens, you may not get support on github, because it's not a bug, and sometimes not easy to answer.
I'm currently developing my iOS app and want to depict a graph whose shape is a circle like pie chart, but its radius is dependent on each specific values. Sorry I don't know what the name of such chart is, but I'm sure every sane baseball fans or any sports fans I think should have ever seen such chart. For example, if a team's batting average is the best in the league which consists of 5 teams, its radius is length 5 (or any other length proportional to the other values), and if the same team's earned runs average is fourth in the league, its length is 2, etc, etc... and then those points or "tips" are connected to each other within the chart, and finally the area of the connected figure is filled with any colors.
Sorry for the awful explanation (it's quite difficult for non-English native to explain it more clearly), but my question is, is it feasible to depict such graphs in iOS application? If it can be done in iOS app, how/what library do I use to plot such graphs?
I've read Core Graphics documentation as well as CorePlot example page but I wasn't able to find any such charts in those pages. I don't like the idea of using D3 embedded in UIWebView as suggested in this post since it's slow due to network latency. I don't know any other libraries to be as flexible and versatile as the two libraries above.
I use iOS 7.1 and Xcode 5.1.
[Update]
It's not a bubble chart. Let me explain it a little bit more concretely. The chart is a hexagon if every component of a record or sample is the best among the other competing records or samples and the number of the component to be described is six. In other words, the length of the component from the origin is whatever the longest possible values. But if one component, say, stolen bases, is NOT the best in the samples - say, it's the second best -, then the length of the component from the origin is not the longest; it's the second longest among the samples. And once every components (6 in this case) is plotted on the graph, those plotted points are connected to each other, and it finally is filled with whatever colors to make it the "area" of the record. And then this might be repeated in other records or samples as well. But unlike the bubble chart, one graph is made of one record and six features (or columns or variables) in this case - not all records and one feature (actually, three, but only one is used to make a bubble) which it is in the case of the bubble chart. Hope you get it...
[Update 2]
I finally got such charts on the Internet! The chart is something like this:
.
You're describing a bubble chart. You can make one with Core Plot using a scatter plot. Implement one of the following datasource methods to provide custom plot symbols. Use your data to determine the size of each symbol. They can be different shapes and have varying fills and border line styles, too.
-(NSArray *)symbolsForScatterPlot:(CPTScatterPlot *)plot recordIndexRange:(NSRange)indexRange;
-(CPTPlotSymbol *)symbolForScatterPlot:(CPTScatterPlot *)plot recordIndex:(NSUInteger)idx;
I want to make a multiple plots with the x-axis aligned so that we can compare two set of data. I want it to look like this
https://stackoverflow.com/a/11796553/229075
In my case there are some addition requirement that some of the plot are lines and some are bar. So the default scale does not align even if the data range are the same.
I found some good suggestion about "stacking" the charts. It is a little bit complicated but a promising way to try.
https://stackoverflow.com/a/12179023/229075
However I also have other use case that may push the envelop of simple stacking. For example, I'd like to do scatter plot matrix sometime when both x-axis and y-axis have to align like this
http://www.statmethods.net/graphs/images/spmatrix3.png
Rather than putting many chart in one Highchart, this may requires have many separate charts but have better control in how the axis is layout.
If you want to use one one chart, you can use linkedTo option to connect axis.
If you want more simple charts, you can manage to connect axis using event afterSetExtremes, where you can call setExtremes() for another chart.