How do you use CPScatterPlotInterpolationLinear? - core-plot

I just happened to stumble across "CPScatterPlotInterpolationLinear" via google search for 'interpolation'.
Does this mean that I could plug gaps of scatter/linear data via interpolation?
I had asked a similar question earlier and was told that CP doesn't add points to a graph.
I attempted to create a 6-month fixed-interval scatter plot by creating an array of 180 elements for 180 days/6 months. The missing data/day were filled with [NSNull null] objects... but CP merely plots the non-nulls without the interpolation.
The 'CPScatterPlotInterpolationLinear' enum got me to re-think.
Question: How do I employ 'CPScatterPlotInterpolationLinear' to interpolate missing data on a graph? ... no need to actually add data points, just 'connect the dots'.

When you set the line style on a scatter plot, Core Plot will connect the data points with a line drawn using the given style. The interpolation property controls how the points are connected:
CPTScatterPlotInterpolationLinear: This is the default. Data points are connected with straight lines drawn directly between successive points.
CPTScatterPlotInterpolationStepped: Steps are drawn beginning at each data point.
CPTScatterPlotInterpolationHistogram: Steps are drawn centered at each data point.
CPTScatterPlotInterpolationCurved: Data points are connected with a smooth curved line drawn between successive points.
None of these styles will add data points (i.e., points that can be indicated with plot symbols or data labels). They simply connect the data points provided by the datasource.

Related

How to depict a radar chart in iOS?

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;

Possible to Draw a Loop With HighCharts

We are currently using HighCharts for our typical bar, pie, line charts. But, we have been asked to plot some medical data that would end up resembling an irregular loop.
If I have an array of x,y points, would it be possible for me to draw this sort of graph with HighCharts? And, if so, can you point me to the right section of the documentation. I see that drawing things like rectangles and circles is possible, but I haven't found any info on drawing lines between arbitrary points.
I can see only three ways to achieve that, and none of them is easy, and have some limitations:
1) Use spline series with unsorted data - looks almost good, only tooltip doesn't work for unsorted data
2) Use scatter series with unsorted data - issue with tooltip is gone, but curves aren't smooth
3) Use renderer.path - doesn't have tooltip at all, and requires to add path manually.
And example of all three: http://jsfiddle.net/kEu3w/

Highstock marker points do not display on line series with grouped data

Using highstock v1.2.2 I am trying to set a few red marker points on a line series with approximately 8000 points.
However, the marker points are only displayed when the data is not being grouped.
When i increase the size of my navigator and the data is grouped, the marker points are no longer displayed.
I searched the highstock api and didn't find anything helpful. All i found was this issue: Fixed issue with disappearing point markers after switching from non, that was fixed about a year ago.
I also tried to increase the turboThreshold attribute with no luck. So how can i display marker points on a large data set when the points are grouped?
You say that you set "a few" marker points. In that case, the markers will disappear when those individual points are grouped with other points, since the global option is that markers are disabled.
As an alternative, you should consider using flags for the points you want to emphasize. Or to make them look like regular point markers, you can even use a scatter series on top of the line series.

How to Set Plot Position in Core Plot

I need to draw multiple plots. How can I set the position of each plot in codes instead of setting one by one in storyboard?
The image I want to achieve is here. In this image, each small curve is a plot. So there are in total 20 x 15 small plots. I need to position and feed different data for each of them. But I don't want to set their positions one by one coz it's tedious.
Do you need to allow user interaction or frequently update the plots? If not, your best bet is to use one graph with a single plot. Render it into small images, once for each plot, changing the data each time. Draw the images into a view laid out in your grid.
If you can't use the image approach, you'll probably run out of memory long before setting up 300 individual graphs. Instead, use one graph with a single plot space if possible. Offset and scale the data values for each plot so they appear in the appropriate section. Use as few plots as you can (one for each line style). Separate the line segments with empty (NAN or nil) data values.

How to display live core plot graph in iPad? [duplicate]

I want to use core-plot for drawing line graph dynamically. data won't come at a time, we will be receiving point by point dynamically.
Is it possible to draw the chart dynamically using core-plot i.e drawing point by point as on when we receive the (x,y) point?
Please help me, Thanks.
Yes, you can do this reasonably easily. For each received data point, append it to an array of values to display. As these data points come in, call -reloadData on the Core Plot graph (or just the particular plot) to redraw the graph, passing in the array you just added a value to in response to the -numbersForPlot:field:recordIndexRange: delegate method.
If you need to adjust the plot range to track your data points (for a moving ticker), recalculate the new CPPlotRange for the X axis and set the plot space's xRange property to that.
Use the CPTestApp-iPhone, AAPLot, or StockPlot examples as templates for how to set up the line chart overall, and modify from that starting point.
I do something similar to this on the Mac in a scientific application:
(source: sunsetlakesoftware.com)
Sounds like you could make use of a demo project I put together and wrote about here (not core plot related though).
It draws a EKG graph but should easily be modified to use another input than the repeated "heart beat"...See line 320 in EAGLView.m where the indata is entered into the array.

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